ConstructorInfo Class

Definition

Namespace:

System.Reflection

Assembly:

System.Runtime.dll

Source:

ConstructorInfo.cs

Discovers the attributes of a class constructor and provides access to constructor metadata.

public ref class ConstructorInfo abstract : System::Reflection::MethodBase

public abstract class ConstructorInfo : System.Reflection.MethodBase

type ConstructorInfo = class
    inherit MethodBase

Public MustInherit Class ConstructorInfo
Inherits MethodBase

Inheritance

Object

MemberInfo

MethodBase

ConstructorInfo

Derived

Microsoft.JScript.JSConstructor

System.Reflection.Emit.ConstructorBuilder

Examples

The following example uses ConstructorInfo with GetConstructor and BindingFlags to find the constructors that match the specified search criteria.

using namespace System;
using namespace System::Reflection;
using namespace System::Security;
public ref class MyClass1
{
public:
   MyClass1( int i ){}

};

int main()
{
   try
   {
      Type^ myType = MyClass1::typeid;
      array<Type^>^types = gcnew array<Type^>(1);
      types[ 0 ] = int::typeid;
      
      // Get the public instance constructor that takes an integer parameter.
      ConstructorInfo^ constructorInfoObj = myType->GetConstructor( static_cast<BindingFlags>(BindingFlags::Instance | BindingFlags::Public), nullptr, CallingConventions::HasThis, types, nullptr );
      if ( constructorInfoObj != nullptr )
      {
         Console::WriteLine( "The constructor of MyClass1 that is a public instance method and takes an integer as a parameter is: " );
         Console::WriteLine( constructorInfoObj );
      }
      else
      {
         Console::WriteLine( "The constructor of MyClass1 that is a public instance method and takes an integer as a parameter is not available." );
      }
   }
   catch ( ArgumentNullException^ e ) 
   {
      Console::WriteLine( "ArgumentNullException: {0}", e->Message );
   }
   catch ( ArgumentException^ e ) 
   {
      Console::WriteLine( "ArgumentException: {0}", e->Message );
   }
   catch ( SecurityException^ e ) 
   {
      Console::WriteLine( "SecurityException: {0}", e->Message );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception: {0}", e->Message );
   }
}

using System;
using System.Reflection;
using System.Security;

public class MyClass3
{
    public MyClass3(int i) { }
    public static void Main()
    {
        try
        {
            Type myType = typeof(MyClass3);
            Type[] types = new Type[1];
            types[0] = typeof(int);
            // Get the public instance constructor that takes an integer parameter.
            ConstructorInfo constructorInfoObj = myType.GetConstructor(
                BindingFlags.Instance | BindingFlags.Public, null,
                CallingConventions.HasThis, types, null);
            if (constructorInfoObj != null)
            {
                Console.WriteLine("The constructor of MyClass3 that is a public " +
                    "instance method and takes an integer as a parameter is: ");
                Console.WriteLine(constructorInfoObj.ToString());
            }
            else
            {
                Console.WriteLine("The constructor of MyClass3 that is a public instance " +
                    "method and takes an integer as a parameter is not available.");
            }
        }
        catch (ArgumentNullException e)
        {
            Console.WriteLine("ArgumentNullException: " + e.Message);
        }
        catch (ArgumentException e)
        {
            Console.WriteLine("ArgumentException: " + e.Message);
        }
        catch (SecurityException e)
        {
            Console.WriteLine("SecurityException: " + e.Message);
        }
        catch (Exception e)
        {
            Console.WriteLine("Exception: " + e.Message);
        }
    }
}

Public Class MyClass1
    Public Sub New(ByVal i As Integer)
    End Sub
    Public Shared Sub Main()
        Try
            Dim myType As Type = GetType(MyClass1)
            Dim types(0) As Type
            types(0) = GetType(Integer)
            ' Get the public instance constructor that takes an integer parameter.
            Dim constructorInfoObj As ConstructorInfo = _
                        myType.GetConstructor(BindingFlags.Instance Or _
                        BindingFlags.Public, Nothing, _
                        CallingConventions.HasThis, types, Nothing)
            If Not (constructorInfoObj Is Nothing) Then
                Console.WriteLine("The constructor of MyClass1 that " + _
                                  "is a public instance method and takes an " + _
                                  "integer as a parameter is: ")
                Console.WriteLine(constructorInfoObj.ToString())
            Else
                Console.WriteLine("The constructor MyClass1 that " + _
                                  "is a public instance method and takes an " + _
                                  "integer as a parameter is not available.")
            End If
        Catch e As ArgumentNullException
            Console.WriteLine("ArgumentNullException: " + e.Message)
        Catch e As ArgumentException
            Console.WriteLine("ArgumentException: " + e.Message)
        Catch e As SecurityException
            Console.WriteLine("SecurityException: " + e.Message)
        Catch e As Exception
            Console.WriteLine("Exception: " + e.Message)
        End Try
    End Sub
End Class

Remarks

ConstructorInfo is used to discover the attributes of a constructor as well as to invoke a constructor. Objects are created by calling Invoke on a ConstructorInfo returned by either the GetConstructors or GetConstructor method of a Type object.

Note

ConstructorInfo inherits from MethodBase several members, such as IsGenericMethod, that can be used to examine generic methods. In the .NET Framework version 2.0 constructors cannot be generic, so these members return false or null.

Notes to Implementers

When you inherit from ConstructorInfo, you must override the following member overload: Invoke(BindingFlags, Binder, Object[], CultureInfo).

Constructors

ConstructorInfo()

Initializes a new instance of the ConstructorInfo class.

Fields

ConstructorName	Represents the name of the class constructor method as it is stored in metadata. This name is always ".ctor". This field is read-only.
TypeConstructorName	Represents the name of the type constructor method as it is stored in metadata. This name is always ".cctor". This property is read-only.

Properties

Attributes	Gets the attributes associated with this method. (Inherited from MethodBase)
CallingConvention	Gets a value indicating the calling conventions for this method. (Inherited from MethodBase)
ContainsGenericParameters	Gets a value indicating whether the generic method contains unassigned generic type parameters. (Inherited from MethodBase)
CustomAttributes	Gets a collection that contains this member's custom attributes. (Inherited from MemberInfo)
DeclaringType	Gets the class that declares this member. (Inherited from MemberInfo)
IsAbstract	Gets a value indicating whether the method is abstract. (Inherited from MethodBase)
IsAssembly	Gets a value indicating whether the potential visibility of this method or constructor is described by Assembly; that is, the method or constructor is visible at most to other types in the same assembly, and is not visible to derived types outside the assembly. (Inherited from MethodBase)
IsCollectible	Gets a value that indicates whether this MemberInfo object is part of an assembly held in a collectible AssemblyLoadContext. (Inherited from MemberInfo)
IsConstructedGenericMethod	(Inherited from MethodBase)
IsConstructor	Gets a value indicating whether the method is a constructor. (Inherited from MethodBase)
IsFamily	Gets a value indicating whether the visibility of this method or constructor is described by Family; that is, the method or constructor is visible only within its class and derived classes. (Inherited from MethodBase)
IsFamilyAndAssembly	Gets a value indicating whether the visibility of this method or constructor is described by FamANDAssem; that is, the method or constructor can be called by derived classes, but only if they are in the same assembly. (Inherited from MethodBase)
IsFamilyOrAssembly	Gets a value indicating whether the potential visibility of this method or constructor is described by FamORAssem; that is, the method or constructor can be called by derived classes wherever they are, and by classes in the same assembly. (Inherited from MethodBase)
IsFinal	Gets a value indicating whether this method is final. (Inherited from MethodBase)
IsGenericMethod	Gets a value indicating whether the method is generic. (Inherited from MethodBase)
IsGenericMethodDefinition	Gets a value indicating whether the method is a generic method definition. (Inherited from MethodBase)
IsHideBySig	Gets a value indicating whether only a member of the same kind with exactly the same signature is hidden in the derived class. (Inherited from MethodBase)
IsPrivate	Gets a value indicating whether this member is private. (Inherited from MethodBase)
IsPublic	Gets a value indicating whether this is a public method. (Inherited from MethodBase)
IsSecurityCritical	Gets a value that indicates whether the current method or constructor is security-critical or security-safe-critical at the current trust level, and therefore can perform critical operations. (Inherited from MethodBase)
IsSecuritySafeCritical	Gets a value that indicates whether the current method or constructor is security-safe-critical at the current trust level; that is, whether it can perform critical operations and can be accessed by transparent code. (Inherited from MethodBase)
IsSecurityTransparent	Gets a value that indicates whether the current method or constructor is transparent at the current trust level, and therefore cannot perform critical operations. (Inherited from MethodBase)
IsSpecialName	Gets a value indicating whether this method has a special name. (Inherited from MethodBase)
IsStatic	Gets a value indicating whether the method is static. (Inherited from MethodBase)
IsVirtual	Gets a value indicating whether the method is virtual. (Inherited from MethodBase)
MemberType	Gets a MemberTypes value indicating that this member is a constructor.
MetadataToken	Gets a value that identifies a metadata element. (Inherited from MemberInfo)
MethodHandle	Gets a handle to the internal metadata representation of a method. (Inherited from MethodBase)
MethodImplementationFlags	Gets the MethodImplAttributes flags that specify the attributes of a method implementation. (Inherited from MethodBase)
Module	Gets the module in which the type that declares the member represented by the current MemberInfo is defined. (Inherited from MemberInfo)
Name	Gets the name of the current member. (Inherited from MemberInfo)
ReflectedType	Gets the class object that was used to obtain this instance of MemberInfo. (Inherited from MemberInfo)

Methods

Equals(Object)	Returns a value that indicates whether this instance is equal to a specified object.
GetCustomAttributes(Boolean)	When overridden in a derived class, returns an array of all custom attributes applied to this member. (Inherited from MemberInfo)
GetCustomAttributes(Type, Boolean)	When overridden in a derived class, returns an array of custom attributes applied to this member and identified by Type. (Inherited from MemberInfo)
GetCustomAttributesData()	Returns a list of CustomAttributeData objects representing data about the attributes that have been applied to the target member. (Inherited from MemberInfo)
GetGenericArguments()	Returns an array of Type objects that represent the type arguments of a generic method or the type parameters of a generic method definition. (Inherited from MethodBase)
GetHashCode()	Returns the hash code for this instance.
GetMethodBody()	When overridden in a derived class, gets a MethodBody object that provides access to the MSIL stream, local variables, and exceptions for the current method. (Inherited from MethodBase)
GetMethodImplementationFlags()	When overridden in a derived class, returns the MethodImplAttributes flags. (Inherited from MethodBase)
GetParameters()	When overridden in a derived class, gets the parameters of the specified method or constructor. (Inherited from MethodBase)
GetType()	(Inherited from MethodBase)
HasSameMetadataDefinitionAs(MemberInfo)	(Inherited from MemberInfo)
Invoke(BindingFlags, Binder, Object[], CultureInfo)	When implemented in a derived class, invokes the constructor reflected by this ConstructorInfo with the specified arguments, under the constraints of the specified Binder.
Invoke(Object, BindingFlags, Binder, Object[], CultureInfo)	When overridden in a derived class, invokes the reflected method or constructor with the given parameters. (Inherited from MethodBase)
Invoke(Object, Object[])	Invokes the method or constructor represented by the current instance, using the specified parameters. (Inherited from MethodBase)
Invoke(Object[])	Invokes the constructor reflected by the instance that has the specified parameters, providing default values for the parameters not commonly used.
IsDefined(Type, Boolean)	When overridden in a derived class, indicates whether one or more attributes of the specified type or of its derived types is applied to this member. (Inherited from MemberInfo)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Operators

Equality(ConstructorInfo, ConstructorInfo)	Indicates whether two ConstructorInfo objects are equal.
Inequality(ConstructorInfo, ConstructorInfo)	Indicates whether two ConstructorInfo objects are not equal.

Extension Methods

GetCustomAttribute(MemberInfo, Type)	Retrieves a custom attribute of a specified type that is applied to a specified member.
GetCustomAttribute(MemberInfo, Type, Boolean)	Retrieves a custom attribute of a specified type that is applied to a specified member, and optionally inspects the ancestors of that member.
GetCustomAttribute<T>(MemberInfo)	Retrieves a custom attribute of a specified type that is applied to a specified member.
GetCustomAttribute<T>(MemberInfo, Boolean)	Retrieves a custom attribute of a specified type that is applied to a specified member, and optionally inspects the ancestors of that member.
GetCustomAttributes(MemberInfo)	Retrieves a collection of custom attributes that are applied to a specified member.
GetCustomAttributes(MemberInfo, Boolean)	Retrieves a collection of custom attributes that are applied to a specified member, and optionally inspects the ancestors of that member.
GetCustomAttributes(MemberInfo, Type)	Retrieves a collection of custom attributes of a specified type that are applied to a specified member.
GetCustomAttributes(MemberInfo, Type, Boolean)	Retrieves a collection of custom attributes of a specified type that are applied to a specified member, and optionally inspects the ancestors of that member.
GetCustomAttributes<T>(MemberInfo)	Retrieves a collection of custom attributes of a specified type that are applied to a specified member.
GetCustomAttributes<T>(MemberInfo, Boolean)	Retrieves a collection of custom attributes of a specified type that are applied to a specified member, and optionally inspects the ancestors of that member.
IsDefined(MemberInfo, Type)	Indicates whether custom attributes of a specified type are applied to a specified member.
IsDefined(MemberInfo, Type, Boolean)	Indicates whether custom attributes of a specified type are applied to a specified member, and, optionally, applied to its ancestors.
GetMetadataToken(MemberInfo)	Gets a metadata token for the given member, if available.
HasMetadataToken(MemberInfo)	Returns a value that indicates whether a metadata token is available for the specified member.

Thread Safety

This type is thread safe.