Activator.CreateInstance Method
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Creates an instance of the specified type using the constructor that best matches the specified parameters.
CreateInstance(AppDomain, String, String, Boolean, BindingFlags, Binder, Object[], CultureInfo, Object[], Evidence) |
Obsolete.
Creates an instance of the type whose name is specified in the specified remote domain, using the named assembly and the constructor that best matches the specified parameters. |
CreateInstance(AppDomain, String, String, Boolean, BindingFlags, Binder, Object[], CultureInfo, Object[]) |
Creates an instance of the type whose name is specified in the specified remote domain, using the named assembly and the constructor that best matches the specified parameters. |
CreateInstance(String, String, Boolean, BindingFlags, Binder, Object[], CultureInfo, Object[]) |
Creates an instance of the type whose name is specified, using the named assembly and the constructor that best matches the specified parameters. |
CreateInstance(Type, BindingFlags, Binder, Object[], CultureInfo, Object[]) |
Creates an instance of the specified type using the constructor that best matches the specified parameters. |
CreateInstance(Type, BindingFlags, Binder, Object[], CultureInfo) |
Creates an instance of the specified type using the constructor that best matches the specified parameters. |
CreateInstance(Type, Object[], Object[]) |
Creates an instance of the specified type using the constructor that best matches the specified parameters. |
CreateInstance(String, String, Object[]) |
Creates an instance of the type whose name is specified, using the named assembly and parameterless constructor. |
CreateInstance(String, String, Boolean, BindingFlags, Binder, Object[], CultureInfo, Object[], Evidence) |
Obsolete.
Creates an instance of the type whose name is specified, using the named assembly and the constructor that best matches the specified parameters. |
CreateInstance(Type, Object[]) |
Creates an instance of the specified type using the constructor that best matches the specified parameters. |
CreateInstance(Type, Boolean) |
Creates an instance of the specified type using that type's parameterless constructor. |
CreateInstance(String, String) |
Creates an instance of the type whose name is specified, using the named assembly and parameterless constructor. |
CreateInstance(ActivationContext, String[]) |
Creates an instance of the type that is designated by the specified ActivationContext object and activated with the specified custom activation data. |
CreateInstance(Type) |
Creates an instance of the specified type using that type's parameterless constructor. |
CreateInstance(ActivationContext) |
Creates an instance of the type designated by the specified ActivationContext object. |
CreateInstance(AppDomain, String, String) |
Creates an instance of the type whose name is specified in the specified remote domain, using the named assembly and parameterless constructor. |
CreateInstance<T>() |
Creates an instance of the type designated by the specified generic type parameter, using the parameterless constructor. |
CreateInstance(AppDomain, String, String, Boolean, BindingFlags, Binder, Object[], CultureInfo, Object[], Evidence)
Caution
Methods which use evidence to sandbox are obsolete and will be removed in a future release of the .NET Framework. Please use an overload of CreateInstance which does not take an Evidence parameter. See http://go.microsoft.com/fwlink/?LinkID=155570 for more information.
Creates an instance of the type whose name is specified in the specified remote domain, using the named assembly and the constructor that best matches the specified parameters.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(AppDomain ^ domain, System::String ^ assemblyName, System::String ^ typeName, bool ignoreCase, System::Reflection::BindingFlags bindingAttr, System::Reflection::Binder ^ binder, cli::array <System::Object ^> ^ args, System::Globalization::CultureInfo ^ culture, cli::array <System::Object ^> ^ activationAttributes, System::Security::Policy::Evidence ^ securityAttributes);
public static System.Runtime.Remoting.ObjectHandle CreateInstance (AppDomain domain, string assemblyName, string typeName, bool ignoreCase, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes, System.Security.Policy.Evidence securityAttributes);
[System.Obsolete("Methods which use evidence to sandbox are obsolete and will be removed in a future release of the .NET Framework. Please use an overload of CreateInstance which does not take an Evidence parameter. See http://go.microsoft.com/fwlink/?LinkID=155570 for more information.")]
[System.Security.SecurityCritical]
public static System.Runtime.Remoting.ObjectHandle CreateInstance (AppDomain domain, string assemblyName, string typeName, bool ignoreCase, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes, System.Security.Policy.Evidence securityAttributes);
static member CreateInstance : AppDomain * string * string * bool * System.Reflection.BindingFlags * System.Reflection.Binder * obj[] * System.Globalization.CultureInfo * obj[] * System.Security.Policy.Evidence -> System.Runtime.Remoting.ObjectHandle
[<System.Obsolete("Methods which use evidence to sandbox are obsolete and will be removed in a future release of the .NET Framework. Please use an overload of CreateInstance which does not take an Evidence parameter. See http://go.microsoft.com/fwlink/?LinkID=155570 for more information.")>]
[<System.Security.SecurityCritical>]
static member CreateInstance : AppDomain * string * string * bool * System.Reflection.BindingFlags * System.Reflection.Binder * obj[] * System.Globalization.CultureInfo * obj[] * System.Security.Policy.Evidence -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (domain As AppDomain, assemblyName As String, typeName As String, ignoreCase As Boolean, bindingAttr As BindingFlags, binder As Binder, args As Object(), culture As CultureInfo, activationAttributes As Object(), securityAttributes As Evidence) As ObjectHandle
Parameters
- domain
- AppDomain
The domain where the type named typeName
is created.
- assemblyName
- String
The name of the assembly where the type named typeName
is sought. If assemblyName
is null
, the executing assembly is searched.
- typeName
- String
The fully qualified name of the type to create an instance of.
- ignoreCase
- Boolean
true
to specify that the search for typeName
is not case-sensitive; false
to specify that the search is case-sensitive.
- bindingAttr
- BindingFlags
A combination of zero or more bit flags that affect the search for the typeName
constructor. If bindingAttr
is zero, a case-sensitive search for public constructors is conducted.
- binder
- Binder
An object that uses bindingAttr
and args
to seek and identify the typeName
constructor. If binder
is null
, the default binder is used.
- args
- Object[]
An array of arguments that match in number, order, and type the parameters of the constructor to invoke. If args
is an empty array or null
, the constructor that takes no parameters (the parameterless constructor) is invoked.
- culture
- CultureInfo
Culture-specific information that governs the coercion of args
to the formal types declared for the typeName
constructor. If culture
is null
, the CultureInfo for the current thread is used.
- activationAttributes
- Object[]
An array of one or more attributes that can participate in activation. This is typically an array that contains a single UrlAttribute object. The UrlAttribute specifies the URL that is required to activate a remote object.
- securityAttributes
- Evidence
Information used to make security policy decisions and grant code permissions.
Returns
A handle that must be unwrapped to access the newly created object, or null
for Nullable<T> instances with no value.
- Attributes
Exceptions
domain
or typeName
is null
.
No matching constructor was found.
typeName
was not found in assemblyName
.
assemblyName
was not found.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The constructor, which was invoked through reflection, threw an exception.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
activationAttributes
is not an empty array, and the type being created does not derive from MarshalByRefObject.
-or-
The constructor that best matches args
has varargs
arguments.
assemblyName
is not a valid assembly.
-or-
The common language runtime (CLR) version 2.0 or later is currently loaded, and assemblyName
was compiled for a version of the CLR that is later than the currently loaded version. Note that the .NET Framework versions 2.0, 3.0, and 3.5 all use CLR version 2.0.
An assembly or module was loaded twice with two different evidences.
-or-
The assembly name or code base is invalid.
Remarks
Use CreateInstance when a host needs to execute code in an application domain that has restricted security permissions.
Use ObjectHandle.Unwrap to unwrap the return value.
Applies to
.NET Framework 4.8.1 och andra versioner
Produkt | Versioner (Föråldrad) |
---|---|
.NET Framework | 2.0, 3.0, 3.5 (4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1) |
CreateInstance(AppDomain, String, String, Boolean, BindingFlags, Binder, Object[], CultureInfo, Object[])
Creates an instance of the type whose name is specified in the specified remote domain, using the named assembly and the constructor that best matches the specified parameters.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(AppDomain ^ domain, System::String ^ assemblyName, System::String ^ typeName, bool ignoreCase, System::Reflection::BindingFlags bindingAttr, System::Reflection::Binder ^ binder, cli::array <System::Object ^> ^ args, System::Globalization::CultureInfo ^ culture, cli::array <System::Object ^> ^ activationAttributes);
[System.Security.SecurityCritical]
public static System.Runtime.Remoting.ObjectHandle CreateInstance (AppDomain domain, string assemblyName, string typeName, bool ignoreCase, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes);
[<System.Security.SecurityCritical>]
static member CreateInstance : AppDomain * string * string * bool * System.Reflection.BindingFlags * System.Reflection.Binder * obj[] * System.Globalization.CultureInfo * obj[] -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (domain As AppDomain, assemblyName As String, typeName As String, ignoreCase As Boolean, bindingAttr As BindingFlags, binder As Binder, args As Object(), culture As CultureInfo, activationAttributes As Object()) As ObjectHandle
Parameters
- domain
- AppDomain
The domain where the type named typeName
is created.
- assemblyName
- String
The name of the assembly where the type named typeName
is sought. If assemblyName
is null
, the executing assembly is searched.
- typeName
- String
The fully qualified name of the type to create an instance of.
- ignoreCase
- Boolean
true
to specify that the search for typeName
is not case-sensitive; false
to specify that the search is case-sensitive.
- bindingAttr
- BindingFlags
A combination of zero or more bit flags that affect the search for the typeName
constructor. If bindingAttr
is zero, a case-sensitive search for public constructors is conducted.
- binder
- Binder
An object that uses bindingAttr
and args
to seek and identify the typeName
constructor. If binder
is null
, the default binder is used.
- args
- Object[]
An array of arguments that match in number, order, and type the parameters of the constructor to invoke. If args
is an empty array or null
, the constructor that takes no parameters (the parameterless constructor) is invoked.
- culture
- CultureInfo
Culture-specific information that governs the coercion of args
to the formal types declared for the typeName
constructor. If culture
is null
, the CultureInfo for the current thread is used.
- activationAttributes
- Object[]
An array of one or more attributes that can participate in activation. This is typically an array that contains a single UrlAttribute object that specifies the URL that is required to activate a remote object.
This parameter is related to client-activated objects. Client activation is a legacy technology that is retained for backward compatibility but is not recommended for new development. Distributed applications should instead use Windows Communication Foundation.
Returns
A handle that must be unwrapped to access the newly created object, or null
for Nullable<T> instances with no value.
- Attributes
Exceptions
domain
or typeName
is null
.
No matching constructor was found.
typeName
was not found in assemblyName
.
assemblyName
was not found.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The constructor, which was invoked through reflection, threw an exception.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
activationAttributes
is not an empty array, and the type being created does not derive from MarshalByRefObject.
-or-
The constructor that best matches args
has varargs
arguments.
assemblyName
is not a valid assembly.
-or-
The common language runtime (CLR) version 2.0 or later is currently loaded, and assemblyName
was compiled for a version of the CLR that is later than the currently loaded version. Note that the .NET Framework versions 2.0, 3.0, and 3.5 all use CLR version 2.0.
An assembly or module was loaded twice with two different evidences.
-or-
The assembly name or code base is invalid.
Remarks
Use CreateInstance when a host needs to execute code in an application domain that has restricted security permissions.
Use ObjectHandle.Unwrap to unwrap the return value.
Applies to
.NET Framework 4.8.1 och andra versioner
Produkt | Versioner |
---|---|
.NET Framework | 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
Creates an instance of the type whose name is specified, using the named assembly and the constructor that best matches the specified parameters.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(System::String ^ assemblyName, System::String ^ typeName, bool ignoreCase, System::Reflection::BindingFlags bindingAttr, System::Reflection::Binder ^ binder, cli::array <System::Object ^> ^ args, System::Globalization::CultureInfo ^ culture, cli::array <System::Object ^> ^ activationAttributes);
public static System.Runtime.Remoting.ObjectHandle? CreateInstance (string assemblyName, string typeName, bool ignoreCase, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder? binder, object?[]? args, System.Globalization.CultureInfo? culture, object?[]? activationAttributes);
public static System.Runtime.Remoting.ObjectHandle CreateInstance (string assemblyName, string typeName, bool ignoreCase, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes);
static member CreateInstance : string * string * bool * System.Reflection.BindingFlags * System.Reflection.Binder * obj[] * System.Globalization.CultureInfo * obj[] -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (assemblyName As String, typeName As String, ignoreCase As Boolean, bindingAttr As BindingFlags, binder As Binder, args As Object(), culture As CultureInfo, activationAttributes As Object()) As ObjectHandle
Parameters
- assemblyName
- String
The name of the assembly where the type named typeName
is sought. If assemblyName
is null
, the executing assembly is searched.
- typeName
- String
The fully qualified name of the type to create an instance of.
- ignoreCase
- Boolean
true
to specify that the search for typeName
is not case-sensitive; false
to specify that the search is case-sensitive.
- bindingAttr
- BindingFlags
A combination of zero or more bit flags that affect the search for the typeName
constructor. If bindingAttr
is zero, a case-sensitive search for public constructors is conducted.
- binder
- Binder
An object that uses bindingAttr
and args
to seek and identify the typeName
constructor. If binder
is null
, the default binder is used.
- args
- Object[]
An array of arguments that match in number, order, and type the parameters of the constructor to invoke. If args
is an empty array or null
, the constructor that takes no parameters (the parameterless constructor) is invoked.
- culture
- CultureInfo
Culture-specific information that governs the coercion of args
to the formal types declared for the typeName
constructor. If culture
is null
, the CultureInfo for the current thread is used.
- activationAttributes
- Object[]
An array of one or more attributes that can participate in activation. This is typically an array that contains a single UrlAttribute object that specifies the URL that is required to activate a remote object.
This parameter is related to client-activated objects. Client activation is a legacy technology that is retained for backward compatibility but is not recommended for new development. Distributed applications should instead use Windows Communication Foundation.
Returns
A handle that must be unwrapped to access the newly created instance, or null
for Nullable<T> instances with no value.
Exceptions
typeName
is null
.
No matching constructor was found.
typeName
was not found in assemblyName
.
assemblyName
was not found.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The constructor, which was invoked through reflection, threw an exception.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
activationAttributes
is not an empty array, and the type being created does not derive from MarshalByRefObject.
-or-
The constructor that best matches args
has varargs
arguments.
assemblyName
is not a valid assembly.
-or-
The common language runtime (CLR) version 2.0 or later is currently loaded, and assemblyName
was compiled for a version of the CLR that is later than the currently loaded version. Note that the .NET Framework versions 2.0, 3.0, and 3.5 all use CLR version 2.0.
An assembly or module was loaded twice with two different evidences.
-or-
The assembly name or code base is invalid.
Remarks
Use ObjectHandle.Unwrap to unwrap the return value.
Anteckning
Starting with .NET Framework 2.0, this method can be used to create nonpublic types and members if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the assembly that contains the nonpublic types and members is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
Creates an instance of the specified type using the constructor that best matches the specified parameters.
public:
static System::Object ^ CreateInstance(Type ^ type, System::Reflection::BindingFlags bindingAttr, System::Reflection::Binder ^ binder, cli::array <System::Object ^> ^ args, System::Globalization::CultureInfo ^ culture, cli::array <System::Object ^> ^ activationAttributes);
public static object? CreateInstance (Type type, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder? binder, object?[]? args, System.Globalization.CultureInfo? culture, object?[]? activationAttributes);
public static object CreateInstance (Type type, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes);
static member CreateInstance : Type * System.Reflection.BindingFlags * System.Reflection.Binder * obj[] * System.Globalization.CultureInfo * obj[] -> obj
Public Shared Function CreateInstance (type As Type, bindingAttr As BindingFlags, binder As Binder, args As Object(), culture As CultureInfo, activationAttributes As Object()) As Object
Parameters
- type
- Type
The type of object to create.
- bindingAttr
- BindingFlags
A combination of zero or more bit flags that affect the search for the type
constructor. If bindingAttr
is zero, a case-sensitive search for public constructors is conducted.
- binder
- Binder
An object that uses bindingAttr
and args
to seek and identify the type
constructor. If binder
is null
, the default binder is used.
- args
- Object[]
An array of arguments that match in number, order, and type the parameters of the constructor to invoke. If args
is an empty array or null
, the constructor that takes no parameters (the parameterless constructor) is invoked.
- culture
- CultureInfo
Culture-specific information that governs the coercion of args
to the formal types declared for the type
constructor. If culture
is null
, the CultureInfo for the current thread is used.
- activationAttributes
- Object[]
An array of one or more attributes that can participate in activation. This is typically an array that contains a single UrlAttribute object that specifies the URL that is required to activate a remote object.
This parameter is related to client-activated objects. Client activation is a legacy technology that is retained for backward compatibility but is not recommended for new development. Distributed applications should instead use Windows Communication Foundation.
Returns
A reference to the newly created object, or null
for Nullable<T> instances with no value.
Exceptions
type
is null
.
type
is not a RuntimeType
.
-or-
type
is an open generic type (that is, the ContainsGenericParameters property returns true
).
type
cannot be a TypeBuilder.
-or-
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
activationAttributes
is not an empty array, and the type being created does not derive from MarshalByRefObject.
-or-
The assembly that contains type
is a dynamic assembly that was created with Save.
-or-
The constructor that best matches args
has varargs
arguments.
The constructor being called throws an exception.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
No matching constructor was found.
type
is a COM object but the class identifier used to obtain the type is invalid, or the identified class is not registered.
type
is not a valid type.
Remarks
The constructor to be invoked must provide the most specific match with the specified argument list under the constraints of the specified binder and binding attributes.
Anteckning
Starting with .NET Framework 2.0, this method can be used to access nonpublic types and members if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the nonpublic types and members is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
- Source:
- Activator.cs
- Source:
- Activator.cs
- Source:
- Activator.cs
Creates an instance of the specified type using the constructor that best matches the specified parameters.
public:
static System::Object ^ CreateInstance(Type ^ type, System::Reflection::BindingFlags bindingAttr, System::Reflection::Binder ^ binder, cli::array <System::Object ^> ^ args, System::Globalization::CultureInfo ^ culture);
public static object? CreateInstance (Type type, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder? binder, object?[]? args, System.Globalization.CultureInfo? culture);
public static object CreateInstance (Type type, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture);
static member CreateInstance : Type * System.Reflection.BindingFlags * System.Reflection.Binder * obj[] * System.Globalization.CultureInfo -> obj
Public Shared Function CreateInstance (type As Type, bindingAttr As BindingFlags, binder As Binder, args As Object(), culture As CultureInfo) As Object
Parameters
- type
- Type
The type of object to create.
- bindingAttr
- BindingFlags
A combination of zero or more bit flags that affect the search for the type
constructor. If bindingAttr
is zero, a case-sensitive search for public constructors is conducted.
- binder
- Binder
An object that uses bindingAttr
and args
to seek and identify the type
constructor. If binder
is null
, the default binder is used.
- args
- Object[]
An array of arguments that match in number, order, and type the parameters of the constructor to invoke. If args
is an empty array or null
, the constructor that takes no parameters (the parameterless constructor) is invoked.
- culture
- CultureInfo
Culture-specific information that governs the coercion of args
to the formal types declared for the type
constructor. If culture
is null
, the CultureInfo for the current thread is used.
Returns
A reference to the newly created object, or null
for Nullable<T> instances with no value.
Exceptions
type
is null
.
type
is not a RuntimeType
.
-or-
type
is an open generic type (that is, the ContainsGenericParameters property returns true
).
type
cannot be a TypeBuilder.
-or-
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
The assembly that contains type
is a dynamic assembly that was created with Save.
-or-
The constructor that best matches args
has varargs
arguments.
The constructor being called throws an exception.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
No matching constructor was found.
type
is a COM object but the class identifier used to obtain the type is invalid, or the identified class is not registered.
type
is not a valid type.
Remarks
The constructor to be invoked must provide the most specific match with the specified argument list under the constraints of the specified binder and binding attributes.
Anteckning
Starting with .NET Framework 2.0, this method can be used to access nonpublic types and members if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the assembly that contains the nonpublic types and members is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
- Source:
- Activator.cs
- Source:
- Activator.cs
- Source:
- Activator.cs
Creates an instance of the specified type using the constructor that best matches the specified parameters.
public:
static System::Object ^ CreateInstance(Type ^ type, cli::array <System::Object ^> ^ args, cli::array <System::Object ^> ^ activationAttributes);
public static object? CreateInstance (Type type, object?[]? args, object?[]? activationAttributes);
public static object CreateInstance (Type type, object[] args, object[] activationAttributes);
static member CreateInstance : Type * obj[] * obj[] -> obj
Public Shared Function CreateInstance (type As Type, args As Object(), activationAttributes As Object()) As Object
Parameters
- type
- Type
The type of object to create.
- args
- Object[]
An array of arguments that match in number, order, and type the parameters of the constructor to invoke. If args
is an empty array or null
, the constructor that takes no parameters (the parameterless constructor) is invoked.
- activationAttributes
- Object[]
An array of one or more attributes that can participate in activation. This is typically an array that contains a single UrlAttribute object that specifies the URL that is required to activate a remote object.
This parameter is related to client-activated objects. Client activation is a legacy technology that is retained for backward compatibility but is not recommended for new development. Distributed applications should instead use Windows Communication Foundation.
Returns
A reference to the newly created object, or null
for Nullable<T> instances with no value.
Exceptions
type
is null
.
type
is not a RuntimeType
.
-or-
type
is an open generic type (that is, the ContainsGenericParameters property returns true
).
type
cannot be a TypeBuilder.
-or-
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
activationAttributes
is not an empty array, and the type being created does not derive from MarshalByRefObject.
-or-
The assembly that contains type
is a dynamic assembly that was created with Save.
-or-
The constructor that best matches args
has varargs
arguments.
The constructor being called throws an exception.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
No matching public constructor was found.
type
is a COM object but the class identifier used to obtain the type is invalid, or the identified class is not registered.
type
is not a valid type.
Remarks
The constructor to be invoked must be accessible and must provide the most specific match with the specified argument list.
Anteckning
Starting with .NET Framework 2.0, this method can be used to access nonpublic types if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the assembly that contains the nonpublic types is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 2.0, 2.1 |
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
Creates an instance of the type whose name is specified, using the named assembly and parameterless constructor.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(System::String ^ assemblyName, System::String ^ typeName, cli::array <System::Object ^> ^ activationAttributes);
public static System.Runtime.Remoting.ObjectHandle? CreateInstance (string assemblyName, string typeName, object?[]? activationAttributes);
public static System.Runtime.Remoting.ObjectHandle CreateInstance (string assemblyName, string typeName, object[] activationAttributes);
static member CreateInstance : string * string * obj[] -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (assemblyName As String, typeName As String, activationAttributes As Object()) As ObjectHandle
Parameters
- assemblyName
- String
The name of the assembly where the type named typeName
is sought. If assemblyName
is null
, the executing assembly is searched.
- typeName
- String
The fully qualified name of the type to create an instance of.
- activationAttributes
- Object[]
An array of one or more attributes that can participate in activation. This is typically an array that contains a single UrlAttribute object that specifies the URL that is required to activate a remote object.
This parameter is related to client-activated objects. Client activation is a legacy technology that is retained for backward compatibility but is not recommended for new development. Distributed applications should instead use Windows Communication Foundation.
Returns
A handle that must be unwrapped to access the newly created object, or null
for Nullable<T> instances.
Exceptions
typeName
is null
.
No matching public constructor was found.
typeName
was not found in assemblyName
.
assemblyName
was not found.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
activationAttributes
is not an empty array, and the type being created does not derive from MarshalByRefObject.
-or-
activationAttributes
is not a UrlAttribute
array.
assemblyName
is not a valid assembly.
-or-
The common language runtime (CLR) version 2.0 or later is currently loaded, and assemblyName
was compiled for a version of the CLR that is later than the currently loaded version. Note that the .NET Framework versions 2.0, 3.0, and 3.5 all use CLR version 2.0.
An assembly or module was loaded twice with two different evidences.
-or-
The assembly name or code base is invalid.
The invoked constructor throws an exception.
-or-
An error occurred when attempting remote activation in a target specified in activationAttributes
.
Remarks
Use ObjectHandle.Unwrap to unwrap the return value.
Anteckning
Starting with .NET Framework 2.0, this method can be used to create nonpublic types if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the nonpublic types is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
CreateInstance(String, String, Boolean, BindingFlags, Binder, Object[], CultureInfo, Object[], Evidence)
Caution
Methods which use evidence to sandbox are obsolete and will be removed in a future release of the .NET Framework. Please use an overload of CreateInstance which does not take an Evidence parameter. See http://go.microsoft.com/fwlink/?LinkID=155570 for more information.
Creates an instance of the type whose name is specified, using the named assembly and the constructor that best matches the specified parameters.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(System::String ^ assemblyName, System::String ^ typeName, bool ignoreCase, System::Reflection::BindingFlags bindingAttr, System::Reflection::Binder ^ binder, cli::array <System::Object ^> ^ args, System::Globalization::CultureInfo ^ culture, cli::array <System::Object ^> ^ activationAttributes, System::Security::Policy::Evidence ^ securityInfo);
public static System.Runtime.Remoting.ObjectHandle CreateInstance (string assemblyName, string typeName, bool ignoreCase, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes, System.Security.Policy.Evidence securityInfo);
[System.Obsolete("Methods which use evidence to sandbox are obsolete and will be removed in a future release of the .NET Framework. Please use an overload of CreateInstance which does not take an Evidence parameter. See http://go.microsoft.com/fwlink/?LinkID=155570 for more information.")]
public static System.Runtime.Remoting.ObjectHandle CreateInstance (string assemblyName, string typeName, bool ignoreCase, System.Reflection.BindingFlags bindingAttr, System.Reflection.Binder binder, object[] args, System.Globalization.CultureInfo culture, object[] activationAttributes, System.Security.Policy.Evidence securityInfo);
static member CreateInstance : string * string * bool * System.Reflection.BindingFlags * System.Reflection.Binder * obj[] * System.Globalization.CultureInfo * obj[] * System.Security.Policy.Evidence -> System.Runtime.Remoting.ObjectHandle
[<System.Obsolete("Methods which use evidence to sandbox are obsolete and will be removed in a future release of the .NET Framework. Please use an overload of CreateInstance which does not take an Evidence parameter. See http://go.microsoft.com/fwlink/?LinkID=155570 for more information.")>]
static member CreateInstance : string * string * bool * System.Reflection.BindingFlags * System.Reflection.Binder * obj[] * System.Globalization.CultureInfo * obj[] * System.Security.Policy.Evidence -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (assemblyName As String, typeName As String, ignoreCase As Boolean, bindingAttr As BindingFlags, binder As Binder, args As Object(), culture As CultureInfo, activationAttributes As Object(), securityInfo As Evidence) As ObjectHandle
Parameters
- assemblyName
- String
The name of the assembly where the type named typeName
is sought. If assemblyName
is null
, the executing assembly is searched.
- typeName
- String
The fully qualified name of the type to create an instance of.
- ignoreCase
- Boolean
true
to specify that the search for typeName
is not case-sensitive; false
to specify that the search is case-sensitive.
- bindingAttr
- BindingFlags
A combination of zero or more bit flags that affect the search for the typeName
constructor. If bindingAttr
is zero, a case-sensitive search for public constructors is conducted.
- binder
- Binder
An object that uses bindingAttr
and args
to seek and identify the typeName
constructor. If binder
is null
, the default binder is used.
- args
- Object[]
An array of arguments that match in number, order, and type the parameters of the constructor to invoke. If args
is an empty array or null
, the constructor that takes no parameters (the parameterless constructor) is invoked.
- culture
- CultureInfo
Culture-specific information that governs the coercion of args
to the formal types declared for the typeName
constructor. If culture
is null
, the CultureInfo for the current thread is used.
- activationAttributes
- Object[]
An array of one or more attributes that can participate in activation. This is typically an array that contains a single UrlAttribute object that specifies the URL that is required to activate a remote object.
This parameter is related to client-activated objects. Client activation is a legacy technology that is retained for backward compatibility but is not recommended for new development. Distributed applications should instead use Windows Communication Foundation.
- securityInfo
- Evidence
Information used to make security policy decisions and grant code permissions.
Returns
A handle that must be unwrapped to access the newly created object, or null
for Nullable<T> instances with no value.
- Attributes
Exceptions
typeName
is null
.
No matching constructor was found.
typeName
was not found in assemblyName
.
assemblyName
was not found.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The constructor, which was invoked through reflection, threw an exception.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
activationAttributes
is not an empty array, and the type being created does not derive from MarshalByRefObject.
-or-
The constructor that best matches args
has varargs
arguments.
assemblyName
is not a valid assembly.
-or-
The common language runtime (CLR) version 2.0 or later is currently loaded, and assemblyName
was compiled for a version of the CLR that is later than the currently loaded version. Note that the .NET Framework versions 2.0, 3.0, and 3.5 all use CLR version 2.0.
An assembly or module was loaded twice with two different evidences.
-or-
The assembly name or code base is invalid.
Remarks
Use ObjectHandle.Unwrap to unwrap the return value.
Anteckning
Starting with .NET Framework 2.0, this method can be used to create nonpublic types and members if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the assembly that contains the nonpublic types and members is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET Framework 4.8.1 och andra versioner
Produkt | Versioner (Föråldrad) |
---|---|
.NET Framework | 1.1, 2.0, 3.0, 3.5 (4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1) |
- Source:
- Activator.cs
- Source:
- Activator.cs
- Source:
- Activator.cs
Creates an instance of the specified type using the constructor that best matches the specified parameters.
public:
static System::Object ^ CreateInstance(Type ^ type, ... cli::array <System::Object ^> ^ args);
public:
static System::Object ^ CreateInstance(Type ^ type, cli::array <System::Object ^> ^ args);
public static object CreateInstance (Type type, params object[] args);
public static object? CreateInstance (Type type, params object?[]? args);
public static object CreateInstance (Type type, object[] args);
static member CreateInstance : Type * obj[] -> obj
Public Shared Function CreateInstance (type As Type, ParamArray args As Object()) As Object
Public Shared Function CreateInstance (type As Type, args As Object()) As Object
Parameters
- type
- Type
The type of object to create.
- args
- Object[]
An array of arguments that match in number, order, and type the parameters of the constructor to invoke. If args
is an empty array or null
, the constructor that takes no parameters (the parameterless constructor) is invoked.
Returns
A reference to the newly created object, or null
for Nullable<T> instances with no value.
Exceptions
type
is null
.
type
is not a RuntimeType
.
-or-
type
is an open generic type (that is, the ContainsGenericParameters property returns true
).
type
cannot be a TypeBuilder.
-or-
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
The assembly that contains type
is a dynamic assembly that was created with Save.
-or-
The constructor that best matches args
has varargs
arguments.
The constructor being called throws an exception.
The caller does not have permission to call this constructor.
Note: In .NET for Windows Store apps or the Portable Class Library, catch the base class exception, MemberAccessException, instead.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
No matching public constructor was found.
Note: In .NET for Windows Store apps or the Portable Class Library, catch the base class exception, MissingMemberException, instead.
type
is a COM object but the class identifier used to obtain the type is invalid, or the identified class is not registered.
type
is not a valid type.
Examples
The following example calls the CreateInstance(Type, Object[]) method to create a String object. It calls the String.String(Char[], Int32, Int32) constructor to instantiate a string that contains ten elements from a character array starting at the fourteenth position.
using System;
public class Example
{
public static void Main()
{
// Initialize array of characters from a to z.
char[] chars = new char[26];
for (int ctr = 0; ctr < 26; ctr++)
chars[ctr] = (char) (ctr + 0x0061);
object obj = Activator.CreateInstance(typeof(string),
new object[] { chars, 13, 10 } );
Console.WriteLine(obj);
}
}
// The example displays the following output:
// nopqrstuvw
open System
// Initialize array of characters from a to z.
let chars = [| 'a' .. 'z' |]
let obj = Activator.CreateInstance(typeof<string>, chars[13..22])
printfn $"{obj}"
// The example displays the following output:
// nopqrstuvw
Module Example
Public Sub Main()
' Initialize array of characters from a to z.
Dim chars(25) As Char
For ctr As Short = 0 To 25
chars(ctr) = ChrW(ctr + &h0061)
Next
Dim obj As Object = Activator.CreateInstance(GetType(String),
{ chars, 13, 10 })
Console.WriteLine(obj)
End Sub
End Module
' The example displays the following output:
' nopqrstuvw
The following example creates a jagged array whose elements are arguments to be passed to a String constructor. The example then passes each array to the CreateInstance(Type, Object[]) method to invoke the appropriate string constructor.
using System;
public class Example
{
public static void Main()
{
char[] characters = { 'a', 'b', 'c', 'd', 'e', 'f' };
object[][] arguments = new object[3][] { new object[] { characters },
new object[] { characters, 1, 4 },
new object[] { characters[1], 20 } };
for (int ctr = 0; ctr <= arguments.GetUpperBound(0); ctr++) {
object[] args = arguments[ctr];
object result = Activator.CreateInstance(typeof(string), args);
Console.WriteLine("{0}: {1}", result.GetType().Name, result);
}
}
}
// The example displays the following output:
// String: abcdef
// String: bcde
// String: bbbbbbbbbbbbbbbbbbbb
open System
let chars = [| 'a' .. 'f' |]
let arguments =
[| chars
chars[1..4]
Array.create 20 chars[1] |]
for args in arguments do
let result =
Activator.CreateInstance(typeof<string>, args)
printfn $"{result.GetType().Name}: {result}"
// The example displays the following output:
// String: abcdef
// String: bcde
// String: bbbbbbbbbbbbbbbbbbbb
Module Example
Public Sub Main()
Dim characters() As Char = { "a"c, "b"c, "c"c, "d"c, "e"c, "f"c }
Dim arguments()() As Object = new Object(2)() { New Object() { characters },
New Object() { characters, 1, 4 },
New Object() { characters(1), 20 } }
For ctr As Integer = 0 To arguments.GetUpperBound(0)
Dim args() As Object = arguments(ctr)
Dim result As Object = Activator.CreateInstance(GetType(String), args)
Console.WriteLine("{0}: {1}", result.GetType().Name, result)
Next
End Sub
End Module
' The example displays the following output:
' String: abcdef
' String: bcde
' String: bbbbbbbbbbbbbbbbbbbb
Remarks
The constructor to be invoked must be accessible and must provide the most specific match with the specified argument list.
Anteckning
Starting with .NET Framework 2.0, this method can be used to access nonpublic types if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the assembly that contains the nonpublic types is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1 |
UWP | 10.0 |
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
Creates an instance of the specified type using that type's parameterless constructor.
public:
static System::Object ^ CreateInstance(Type ^ type, bool nonPublic);
public static object? CreateInstance (Type type, bool nonPublic);
public static object CreateInstance (Type type, bool nonPublic);
static member CreateInstance : Type * bool -> obj
Public Shared Function CreateInstance (type As Type, nonPublic As Boolean) As Object
Parameters
- type
- Type
The type of object to create.
- nonPublic
- Boolean
true
if a public or nonpublic parameterless constructor can match; false
if only a public parameterless constructor can match.
Returns
A reference to the newly created object, or null
for Nullable<T> instances.
Exceptions
type
is null
.
type
is not a RuntimeType
.
-or-
type
is an open generic type (that is, the ContainsGenericParameters property returns true
).
type
cannot be a TypeBuilder.
-or-
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
The assembly that contains type
is a dynamic assembly that was created with Save.
The constructor being called throws an exception.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
No matching public constructor was found.
type
is a COM object but the class identifier used to obtain the type is invalid, or the identified class is not registered.
type
is not a valid type.
Remarks
Anteckning
Starting with .NET Framework 2.0, this method can be used to access nonpublic types and members if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the assembly that contains the nonpublic types and members is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.5, 1.6, 2.0, 2.1 |
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
Creates an instance of the type whose name is specified, using the named assembly and parameterless constructor.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(System::String ^ assemblyName, System::String ^ typeName);
public static System.Runtime.Remoting.ObjectHandle? CreateInstance (string assemblyName, string typeName);
public static System.Runtime.Remoting.ObjectHandle CreateInstance (string assemblyName, string typeName);
static member CreateInstance : string * string -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (assemblyName As String, typeName As String) As ObjectHandle
Parameters
- assemblyName
- String
The name of the assembly where the type named typeName
is sought. If assemblyName
is null
, the executing assembly is searched.
- typeName
- String
The fully qualified name of the type to create an instance of.
Returns
A handle that must be unwrapped to access the newly created object, or null
for Nullable<T> instances.
Exceptions
typeName
is null
.
No matching public constructor was found.
typeName
was not found in assemblyName
.
assemblyName
was not found.
The caller does not have permission to call this constructor.
You cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The constructor, which was invoked through reflection, threw an exception.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
assemblyName
is not a valid assembly.
-or-
The common language runtime (CLR) version 2.0 or later is currently loaded, and assemblyName
was compiled for a version of the CLR that is later than the currently loaded version. Note that the .NET Framework versions 2.0, 3.0, and 3.5 all use CLR version 2.0.
An assembly or module was loaded twice with two different evidences.
-or-
The assembly name or code base is invalid.
Examples
The following example defines a class named Person
in an assembly named PersonInfo
. Note that the Person
class has two constructors, one of which is parameterless.
using System;
public class Person
{
private string _name;
public Person()
{ }
public Person(string name)
{
this._name = name;
}
public string Name
{ get { return this._name; }
set { this._name = value; } }
public override string ToString()
{
return this._name;
}
}
type Person(name) =
member val Name = name with get, set
override this.ToString() = this.Name
new () = Person Unchecked.defaultof<string>
Public Class Person
Private _name As String
Public Sub New()
End Sub
Public Sub New(name As String)
Me._name = name
End Sub
Public Property Name As String
Get
Return Me._name
End Get
Set
Me._name = value
End Set
End Property
Public Overrides Function ToString() As String
Return Me._name
End Function
End Class
The following example calls the CreateInstance(String, String) method to instantiate the Person
class. It requires a reference to PersonInfo.dll to be added to the project. Because the CreateInstance(String, String) method calls the Person
class parameterless constructor, the example assigns a value to its Name
property.
using System;
using System.Runtime.Remoting;
public class Example
{
public static void Main()
{
ObjectHandle handle = Activator.CreateInstance("PersonInfo", "Person");
Person p = (Person) handle.Unwrap();
p.Name = "Samuel";
Console.WriteLine(p);
}
}
// The example displays the following output:
// Samuel
open System
let handle = Activator.CreateInstance("PersonInfo", "Person")
let p = handle.Unwrap() :?> Person
p.Name <- "Samuel"
printfn $"{p}"
// The example displays the following output:
// Samuel
Imports System.Runtime.Remoting
Module Example
Public Sub Main()
Dim handle As ObjectHandle = Activator.CreateInstance("PersonInfo", "Person")
Dim p As Person = CType(handle.Unwrap(), Person)
p.Name = "Samuel"
Console.WriteLine(p)
End Sub
End Module
' The example displays the following output:
' Samuel
However, CreateInstance is frequently called to instantiate a type that crosses machine boundaries or that is not known at design time. In this case, you cannot include a reference to the assembly in the project and cannot make early-bound calls to the type's members. To work around this limitation, the following example uses the CreateInstance method along with reflection to assign a value to the Person
object's Name
property and to display its value.
using System;
using System.Reflection;
using System.Runtime.Remoting;
public class Example
{
public static void Main()
{
ObjectHandle handle = Activator.CreateInstance("PersonInfo", "Person");
object p = handle.Unwrap();
Type t = p.GetType();
PropertyInfo prop = t.GetProperty("Name");
if (prop != null)
prop.SetValue(p, "Samuel");
MethodInfo method = t.GetMethod("ToString");
object retVal = method.Invoke(p, null);
if (retVal != null)
Console.WriteLine(retVal);
}
}
// The example displays the following output:
// Samuel
open System
let handle =
Activator.CreateInstance("PersonInfo", "Person")
let p = handle.Unwrap()
let t = p.GetType()
let prop = t.GetProperty "Name"
if not (isNull prop) then
prop.SetValue(p, "Samuel")
let method = t.GetMethod "ToString"
let retVal = method.Invoke(p, null)
if not (isNull retVal) then
printfn $"{retVal}"
// The example displays the following output:
// Samuel
Imports System.Reflection
Imports System.Runtime.Remoting
Module Example
Public Sub Main()
Dim handle As ObjectHandle = Activator.CreateInstance("PersonInfo", "Person")
Dim p As Object = handle.Unwrap()
Dim t As Type = p.GetType()
Dim prop As PropertyInfo = t.GetProperty("Name")
if Not prop Is Nothing Then
prop.SetValue(p, "Samuel")
End If
Dim method As MethodInfo = t.GetMethod("ToString")
Dim retVal As Object = method.Invoke(p, Nothing)
If Not retVal Is Nothing Then
Console.WriteLine(retVal)
End If
End Sub
End Module
' The example displays the following output:
' Samuel
Remarks
Use ObjectHandle.Unwrap to unwrap the return value.
assemblyName
can be either of the following:
The simple name of an assembly, without its path or file extension. For example, you would specify
TypeExtensions
for an assembly whose path and name are .\bin\TypeExtensions.dll.The full name of a signed assembly, which consists of its simple name, version, culture, and public key token; for example, "TypeExtensions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=181869f2f7435b51".
For more information on how the common language runtime identifies and loads assemblies, see How the Runtime Locates Assemblies. For information on using the application configuration file to define assembly locations, see Specifying an Assembly's Location. If assemblyName
is found, it is loaded in the default context.
Anteckning
Starting with .NET Framework 2.0, this method can be used to create nonpublic types if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the assembly that contains the nonpublic types is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
Creates an instance of the type that is designated by the specified ActivationContext object and activated with the specified custom activation data.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(ActivationContext ^ activationContext, cli::array <System::String ^> ^ activationCustomData);
public static System.Runtime.Remoting.ObjectHandle CreateInstance (ActivationContext activationContext, string[] activationCustomData);
static member CreateInstance : ActivationContext * string[] -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (activationContext As ActivationContext, activationCustomData As String()) As ObjectHandle
Parameters
- activationContext
- ActivationContext
An activation context object that specifies the object to create.
- activationCustomData
- String[]
An array of Unicode strings that contain custom activation data.
Returns
A handle that must be unwrapped to access the newly created object, or null
for Nullable<T> instances.
Remarks
Use the ObjectHandle.Unwrap method to unwrap the return value.
The activation context is used during manifest-based activation to set up the domain policy and to provide an application-based security model. The ActivationContext class contains an ApplicationIdentity object that provides access to the application manifest. For more information, see the ApplicationSecurityManager class.
See also
Applies to
.NET Framework 4.8.1 och andra versioner
Produkt | Versioner |
---|---|
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
- Source:
- Activator.cs
- Source:
- Activator.cs
- Source:
- Activator.cs
Creates an instance of the specified type using that type's parameterless constructor.
public:
static System::Object ^ CreateInstance(Type ^ type);
public static object CreateInstance (Type type);
public static object? CreateInstance (Type type);
static member CreateInstance : Type -> obj
Public Shared Function CreateInstance (type As Type) As Object
Parameters
- type
- Type
The type of object to create.
Returns
A reference to the newly created object, or null
for Nullable<T> instances.
Exceptions
type
is null
.
type
is not a RuntimeType
.
-or-
type
is an open generic type (that is, the ContainsGenericParameters property returns true
).
type
cannot be a TypeBuilder.
-or-
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
-or-
The assembly that contains type
is a dynamic assembly that was created with Save.
The constructor being called throws an exception.
The caller does not have permission to call this constructor.
Note: In .NET for Windows Store apps or the Portable Class Library, catch the base class exception, MemberAccessException, instead.
Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
No matching public constructor was found.
Note: In .NET for Windows Store apps or the Portable Class Library, catch the base class exception, MissingMemberException, instead.
type
is a COM object but the class identifier used to obtain the type is invalid, or the identified class is not registered.
type
is not a valid type.
Examples
The following code example demonstrates how to call the CreateInstance(Type) method. Instances of several different types are created and their default values are displayed.
using namespace System;
ref class DynamicInstanceList
{
private:
static String^ instanceSpec = "System.EventArgs;System.Random;" +
"System.Exception;System.Object;System.Version";
public:
static void Main()
{
array<String^>^ instances = instanceSpec->Split(';');
Array^ instlist = Array::CreateInstance(Object::typeid, instances->Length);
Object^ item;
for (int i = 0; i < instances->Length; i++)
{
// create the object from the specification string
Console::WriteLine("Creating instance of: {0}", instances[i]);
item = Activator::CreateInstance(Type::GetType(instances[i]));
instlist->SetValue(item, i);
}
Console::WriteLine("\nObjects and their default values:\n");
for each (Object^ o in instlist)
{
Console::WriteLine("Type: {0}\nValue: {1}\nHashCode: {2}\n",
o->GetType()->FullName, o->ToString(), o->GetHashCode());
}
}
};
int main()
{
DynamicInstanceList::Main();
}
// This program will display output similar to the following:
//
// Creating instance of: System.EventArgs
// Creating instance of: System.Random
// Creating instance of: System.Exception
// Creating instance of: System.Object
// Creating instance of: System.Version
//
// Objects and their default values:
//
// Type: System.EventArgs
// Value: System.EventArgs
// HashCode: 46104728
//
// Type: System.Random
// Value: System.Random
// HashCode: 12289376
//
// Type: System.Exception
// Value: System.Exception: Exception of type 'System.Exception' was thrown.
// HashCode: 55530882
//
// Type: System.Object
// Value: System.Object
// HashCode: 30015890
//
// Type: System.Version
// Value: 0.0
// HashCode: 1048575
using System;
class DynamicInstanceList
{
private static string instanceSpec = "System.EventArgs;System.Random;" +
"System.Exception;System.Object;System.Version";
public static void Main()
{
string[] instances = instanceSpec.Split(';');
Array instlist = Array.CreateInstance(typeof(object), instances.Length);
object item;
for (int i = 0; i < instances.Length; i++)
{
// create the object from the specification string
Console.WriteLine("Creating instance of: {0}", instances[i]);
item = Activator.CreateInstance(Type.GetType(instances[i]));
instlist.SetValue(item, i);
}
Console.WriteLine("\nObjects and their default values:\n");
foreach (object o in instlist)
{
Console.WriteLine("Type: {0}\nValue: {1}\nHashCode: {2}\n",
o.GetType().FullName, o.ToString(), o.GetHashCode());
}
}
}
// This program will display output similar to the following:
//
// Creating instance of: System.EventArgs
// Creating instance of: System.Random
// Creating instance of: System.Exception
// Creating instance of: System.Object
// Creating instance of: System.Version
//
// Objects and their default values:
//
// Type: System.EventArgs
// Value: System.EventArgs
// HashCode: 46104728
//
// Type: System.Random
// Value: System.Random
// HashCode: 12289376
//
// Type: System.Exception
// Value: System.Exception: Exception of type 'System.Exception' was thrown.
// HashCode: 55530882
//
// Type: System.Object
// Value: System.Object
// HashCode: 30015890
//
// Type: System.Version
// Value: 0.0
// HashCode: 1048575
open System
let instanceSpec =
"System.EventArgs;System.Random;System.Exception;System.Object;System.Version"
let instances = instanceSpec.Split ';'
let instlist = Array.zeroCreate instances.Length
let mutable item = obj ()
for i = 0 to instances.Length - 1 do
// create the object from the specification string
printfn $"Creating instance of: {instances.[i]}"
item <- Activator.CreateInstance(Type.GetType instances.[i])
instlist.[i] <- item
printfn "\nObjects and their default values:\n"
for o in instlist do
printfn $"Type: {o.GetType().FullName}\nValue: {o}\nHashCode: {o.GetHashCode()}\n"
// This program will display output similar to the following:
//
// Creating instance of: System.EventArgs
// Creating instance of: System.Random
// Creating instance of: System.Exception
// Creating instance of: System.Object
// Creating instance of: System.Version
//
// Objects and their default values:
//
// Type: System.EventArgs
// Value: System.EventArgs
// HashCode: 46104728
//
// Type: System.Random
// Value: System.Random
// HashCode: 12289376
//
// Type: System.Exception
// Value: System.Exception: Exception of type 'System.Exception' was thrown.
// HashCode: 55530882
//
// Type: System.Object
// Value: System.Object
// HashCode: 30015890
//
// Type: System.Version
// Value: 0.0
// HashCode: 1048575
Class DynamicInstanceList
Private Shared instanceSpec As String = "System.EventArgs;System.Random;" + _
"System.Exception;System.Object;System.Version"
Public Shared Sub Main()
Dim instances() As String = instanceSpec.Split(";")
Dim instlist As Array = Array.CreateInstance(GetType(Object), instances.Length)
Dim item As Object
For i As Integer = 0 To instances.Length -1
' create the object from the specification string
Console.WriteLine("Creating instance of: {0}", instances(i))
item = Activator.CreateInstance(Type.GetType(instances(i)))
instlist.SetValue(item, i)
Next i
Console.WriteLine(Environment.NewLine + "Objects and their default values:" + Environment.NewLine)
For Each o As Object In instlist
Console.WriteLine("Type: {0}" + Environment.NewLine + "Value: {1}" + _
Environment.NewLine + "HashCode: {2}" + Environment.NewLine, _
o.GetType().FullName, o.ToString(), o.GetHashCode())
Next o
End Sub
End Class
' This program will display output similar to the following:
'
' Creating instance of: System.EventArgs
' Creating instance of: System.Random
' Creating instance of: System.Exception
' Creating instance of: System.Object
' Creating instance of: System.Version
'
' Objects and their default values:
'
' Type: System.EventArgs
' Value: System.EventArgs
' HashCode: 46104728
'
' Type: System.Random
' Value: System.Random
' HashCode: 12289376
'
' Type: System.Exception
' Value: System.Exception: Exception of type 'System.Exception' was thrown.
' HashCode: 55530882
'
' Type: System.Object
' Value: System.Object
' HashCode: 30015890
'
' Type: System.Version
' Value: 0.0
' HashCode: 1048575
Remarks
The constructor to be invoked must be accessible.
Anteckning
Starting with .NET Framework 2.0, this method can be used to access nonpublic types if the caller has been granted ReflectionPermission with the ReflectionPermissionFlag.RestrictedMemberAccess flag and if the grant set of the assembly that contains the nonpublic types is restricted to the caller's grant set or to a subset thereof. (See Security Considerations for Reflection.) To use this functionality, your application should target .NET Framework 3.5 or later.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1 |
UWP | 10.0 |
Creates an instance of the type designated by the specified ActivationContext object.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(ActivationContext ^ activationContext);
public static System.Runtime.Remoting.ObjectHandle CreateInstance (ActivationContext activationContext);
static member CreateInstance : ActivationContext -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (activationContext As ActivationContext) As ObjectHandle
Parameters
- activationContext
- ActivationContext
An activation context object that specifies the object to create.
Returns
A handle that must be unwrapped to access the newly created object, or null
for Nullable<T> instances.
Remarks
Use the ObjectHandle.Unwrap method to unwrap the return value.
The activation context is used during manifest-based activation to set up the domain policy and to provide an application-based security model. The ActivationContext class contains an ApplicationIdentity object that provides access to the application manifest. For more information, see the ApplicationSecurityManager class.
See also
Applies to
.NET Framework 4.8.1 och andra versioner
Produkt | Versioner |
---|---|
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
Creates an instance of the type whose name is specified in the specified remote domain, using the named assembly and parameterless constructor.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateInstance(AppDomain ^ domain, System::String ^ assemblyName, System::String ^ typeName);
public static System.Runtime.Remoting.ObjectHandle CreateInstance (AppDomain domain, string assemblyName, string typeName);
[System.Security.SecurityCritical]
public static System.Runtime.Remoting.ObjectHandle CreateInstance (AppDomain domain, string assemblyName, string typeName);
static member CreateInstance : AppDomain * string * string -> System.Runtime.Remoting.ObjectHandle
[<System.Security.SecurityCritical>]
static member CreateInstance : AppDomain * string * string -> System.Runtime.Remoting.ObjectHandle
Public Shared Function CreateInstance (domain As AppDomain, assemblyName As String, typeName As String) As ObjectHandle
Parameters
- domain
- AppDomain
The remote domain where the type named typeName
is created.
- assemblyName
- String
The name of the assembly where the type named typeName
is sought. If assemblyName
is null
, the executing assembly is searched.
- typeName
- String
The fully qualified name of the type to create an instance of.
Returns
A handle that must be unwrapped to access the newly created object, or null
for Nullable<T> instances.
- Attributes
Exceptions
typeName
or domain
is null
.
No matching public constructor was found.
typeName
was not found in assemblyName
.
assemblyName
was not found.
The caller does not have permission to call this constructor.
Cannot create an instance of an abstract type.
-or-
This member was invoked with a late-binding mechanism.
The constructor, which was invoked through reflection, threw an exception.
The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.
Creation of TypedReference, ArgIterator, Void, and RuntimeArgumentHandle types, or arrays of those types, is not supported.
assemblyName
is not a valid assembly.
-or-
The common language runtime (CLR) version 2.0 or later is currently loaded, and assemblyName
was compiled for a version of the CLR that is later than the currently loaded version. Note that the .NET Framework versions 2.0, 3.0, and 3.5 all use CLR version 2.0.
An assembly or module was loaded twice with two different evidences.
-or-
The assembly name or code base is invalid.
Remarks
Use CreateInstance when a host needs to execute code in an application domain that has restricted security permissions.
Use ObjectHandle.Unwrap to unwrap the return value.
Applies to
.NET Framework 4.8.1 och andra versioner
Produkt | Versioner |
---|---|
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
- Source:
- Activator.RuntimeType.cs
Creates an instance of the type designated by the specified generic type parameter, using the parameterless constructor.
public:
generic <typename T>
static T CreateInstance();
public static T CreateInstance<T> ();
static member CreateInstance : unit -> 'T
Public Shared Function CreateInstance(Of T) () As T
Type Parameters
- T
The type to create.
Returns
A reference to the newly created object, or null
for Nullable<T> instances.
Exceptions
Cannot create an instance of an abstract class, or the type that is specified for T
does not have a parameterless constructor.
Note: In .NET for Windows Store apps or the Portable Class Library, catch the base class exception, MissingMemberException, instead.
Remarks
The CreateInstance<T>() generic method is used by compilers to implement the instantiation of types specified by type parameters. For example, in the following generic method, the implementation of new T()
(gcnew T()
in C++) uses the CreateInstance<T>() generic method.
public:
generic <typename T> where T:gcnew()
static T Bar()
{
return gcnew T();
}
public static T Factory<T>() where T : new()
{
return new T();
}
let factory<'T when 'T : (new: unit -> 'T)> =
new 'T()
Public Shared Function Factory(Of T As New)() As T
Return New T()
End Function
In general, there is no use for the CreateInstance<T>() generic method in application code, because the type must be known at compile time. If the type is known at compile time, normal instantiation syntax can be used (new
operator in C#, New
in Visual Basic, gcnew
in C++). If the type is not known at compile time, you can call a non-generic overload of CreateInstance.
There are no overloads of the CreateInstance<T>() generic method that take argument lists, because the non-generic overloads of CreateInstance already provide late-bound constructor resolution.
Applies to
.NET 9 och andra versioner
Produkt | Versioner |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1 |
UWP | 10.0 |
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