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Activator.CreateInstance Method (Type)

Creates an instance of the specified type using that type's default constructor.

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

public static Object CreateInstance(
	Type type
)

Parameters

type
Type: System.Type
The type of object to create.

Return Value

Type: System.Object
A reference to the newly created object.

ExceptionCondition
ArgumentNullException

type is null.

ArgumentException

type is not a RuntimeType.

-or-

type is an open generic type (that is, the ContainsGenericParameters property returns true).

NotSupportedException

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 AssemblyBuilderAccess.Save.

TargetInvocationException

The constructor being called throws an exception.

MethodAccessException

The caller does not have permission to call this constructor.

MemberAccessException

Cannot create an instance of an abstract class, or this member was invoked with a late-binding mechanism.

InvalidComObjectException

The COM type was not obtained through GetTypeFromProgID or GetTypeFromCLSID.

MissingMethodException

No matching public constructor was found.

COMException

type is a COM object but the class identifier used to obtain the type is invalid, or the identified class is not registered.

TypeLoadException

type is not a valid type.

The constructor to be invoked must be accessible.

NoteNote

Starting with the .NET Framework version 2.0 Service Pack 1, 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 the .NET Framework version 3.5 or later.

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 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


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

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