Activator.CreateComInstanceFrom Method
Definition
Important
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Creates an instance of the COM object whose name is specified.
Overloads
| CreateComInstanceFrom(String, String) |
Creates an instance of the COM object whose name is specified, using the named assembly file and the parameterless constructor. |
| CreateComInstanceFrom(String, String, Byte[], AssemblyHashAlgorithm) |
Creates an instance of the COM object whose name is specified, using the named assembly file and the parameterless constructor. |
CreateComInstanceFrom(String, String)
Creates an instance of the COM object whose name is specified, using the named assembly file and the parameterless constructor.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateComInstanceFrom(System::String ^ assemblyName, System::String ^ typeName);public static System.Runtime.Remoting.ObjectHandle CreateComInstanceFrom (string assemblyName, string typeName);static member CreateComInstanceFrom : string * string -> System.Runtime.Remoting.ObjectHandlePublic Shared Function CreateComInstanceFrom (assemblyName As String, typeName As String) As ObjectHandleParameters
- assemblyName
- String
The name of a file that contains an assembly where the type named typeName is sought.
- typeName
- String
The 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 or assemblyName is null.
An instance cannot be created through COM.
-or-
typeName was not found in assemblyName.
No matching constructor was found.
assemblyName is not found, or the module you are trying to load does not specify a file name extension.
Cannot create an instance of an abstract class.
-or-
This member was invoked with a late-binding mechanism.
The caller cannot provide activation attributes for an object that does not inherit from MarshalByRefObject.
assemblyName is the empty string ("").
Remarks
Use the ObjectHandle.Unwrap method to unwrap the return value.
A System.Runtime.InteropServices.ComVisibleAttribute attribute with a value of true must be applied either explicitly or by default to the COM type so the CreateComInstanceFrom method can create an instance of that type; otherwise, TypeLoadException is thrown.
For information about other exceptions that can be thrown by invoked methods, see the Exceptions section of the Assembly.LoadFrom and CreateInstance methods.
Note
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
CreateComInstanceFrom(String, String, Byte[], AssemblyHashAlgorithm)
Creates an instance of the COM object whose name is specified, using the named assembly file and the parameterless constructor.
public:
static System::Runtime::Remoting::ObjectHandle ^ CreateComInstanceFrom(System::String ^ assemblyName, System::String ^ typeName, cli::array <System::Byte> ^ hashValue, System::Configuration::Assemblies::AssemblyHashAlgorithm hashAlgorithm);public static System.Runtime.Remoting.ObjectHandle CreateComInstanceFrom (string assemblyName, string typeName, byte[] hashValue, System.Configuration.Assemblies.AssemblyHashAlgorithm hashAlgorithm);static member CreateComInstanceFrom : string * string * byte[] * System.Configuration.Assemblies.AssemblyHashAlgorithm -> System.Runtime.Remoting.ObjectHandlePublic Shared Function CreateComInstanceFrom (assemblyName As String, typeName As String, hashValue As Byte(), hashAlgorithm As AssemblyHashAlgorithm) As ObjectHandleParameters
- assemblyName
- String
The name of a file that contains an assembly where the type named typeName is sought.
- typeName
- String
The name of the type to create an instance of.
- hashValue
- Byte[]
The value of the computed hash code.
- hashAlgorithm
- AssemblyHashAlgorithm
The hash algorithm used for hashing files and generating the strong name.
Returns
A handle that must be unwrapped to access the newly created object, or null for Nullable<T> instances.
Exceptions
typeName or assemblyName is null.
assemblyName is the empty string ("").
An assembly or module was loaded twice with two different evidences.
-or-
assemblyName is longer than the system-defined maximum length.
assemblyName is not found, or the module you are trying to load does not specify a file name extension.
assemblyName is found but cannot be loaded.
assemblyName is not a valid assembly.
A code base that does not start with "file://" was specified without the required WebPermission.
An instance cannot be created through COM.
-or-
typeName was not found in assemblyName.
No matching constructor was found.
An instance of an abstract class cannot be created.
-or-
This member was invoked with a late-binding mechanism.
The caller cannot provide activation attributes for an object that does not inherit from MarshalByRefObject.
Remarks
Use the ObjectHandle.Unwrap method to unwrap the return value.
A System.Runtime.InteropServices.ComVisibleAttribute attribute with a value of true must be applied either explicitly or by default to the COM type so the CreateComInstanceFrom method can create an instance of that type; otherwise, TypeLoadException is thrown.
For information about other exceptions that can be thrown by invoked methods, see the Exceptions section of the Assembly.LoadFrom and CreateInstance methods.
Note
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.
