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Activator.CreateInstance Method (String, String, Object[])

Creates an instance of the type whose name is specified, using the named assembly and default constructor.

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

public static ObjectHandle CreateInstance(
	string assemblyName,
	string typeName,
	Object[] activationAttributes


Type: System.String

The name of the assembly where the type named typeName is sought. If assemblyName is null, the executing assembly is searched.

Type: System.String

The name of the preferred type.

Type: System.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.

Return Value

Type: System.Runtime.Remoting.ObjectHandle
A handle that must be unwrapped to access the newly created instance.


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.


activationAttributes is not an empty array, and the type being created does not derive from MarshalByRefObject.


activationAttributes is not a UrlAttribute



assemblyName is not a valid assembly.


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.


An error occurred when attempting remote activation in a target specified in activationAttributes.

Use ObjectHandle.Unwrap to unwrap the return value.

The activationAttributes parameter is related to client-activated objects; see Client Activation.


Starting with the .NET Framework version 2.0 Service Pack 1, 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 the .NET Framework version 3.5. For more information, see .NET Framework 3.5 Architecture.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

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