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ConstructorInfo Class

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

Namespace: System.Reflection
Assembly: mscorlib (in mscorlib.dll)

[SerializableAttribute] 
[ComVisibleAttribute(true)] 
[ClassInterfaceAttribute(ClassInterfaceType.None)] 
public abstract class ConstructorInfo : MethodBase, _ConstructorInfo
/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
/** @attribute ClassInterfaceAttribute(ClassInterfaceType.None) */ 
public abstract class ConstructorInfo extends MethodBase implements _ConstructorInfo
SerializableAttribute 
ComVisibleAttribute(true) 
ClassInterfaceAttribute(ClassInterfaceType.None) 
public abstract class ConstructorInfo extends MethodBase implements _ConstructorInfo

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.

NoteNote

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 a null reference (Nothing in Visual Basic).

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

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

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

public class MyClass1
{
    public MyClass1(int i){}
    public static void Main()
    {
        try
        {
            Type  myType = typeof(MyClass1);
            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 MyClass1 that is a public " +
                    "instance method and takes an integer as a parameter is: ");
                Console.WriteLine(constructorInfoObj.ToString());
            }
            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: " + 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);
        }
    }
}

import System.*;
import System.Reflection.*;
import System.Security.*;

public class MyClass1
{
    public MyClass1(int i)
    {
    } //MyClass1

    public static void main(String[] args)
    {
        try {
            Type myType = MyClass1.class.ToType();
            Type types[] = new Type[1];
            types.set_Item(0, int.class.ToType());
            // 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 MyClass1 that is a public "
                    + "instance method and takes an integer as a parameter is: ");
                Console.WriteLine(constructorInfoObj.ToString());
            }
            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: " + e.get_Message());
        }
        catch (ArgumentException e) {
            Console.WriteLine("ArgumentException: " + e.get_Message());
        }
        catch (SecurityException e) {
            Console.WriteLine("SecurityException: " + e.get_Message());
        }
        catch (System.Exception e) {
            Console.WriteLine("Exception: " + e.get_Message());
        }
    } //main
} //MyClass1

This type is safe for multithreaded operations.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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