CreateInstance Method (Type)

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.

Exception Condition
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
System_CAPS_noteNote

In the .NET for Windows Store apps or the Portable Class Library, catch the base class exception, MemberAccessException, instead.

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
System_CAPS_noteNote

In the .NET for Windows Store apps or the Portable Class Library, catch the base class exception, MissingMemberException, instead.

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.

System_CAPS_noteNote

Starting with the .NET Framework 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 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

SecurityPermission

for the ability to call unmanaged code when creating an instance of a delegate. Associated enumeration: SecurityPermissionFlag.UnmanagedCode

ReflectionPermission

for accessing a nonpublic type when the grant set of the nonpublic type is restricted to the caller's grant set or to a subset thereof. Associated enumeration: ReflectionPermissionFlag.RestrictedMemberAccess

ReflectionPermission

for accessing nonpublic types regardless of their grant sets. Associated enumeration: ReflectionPermissionFlag.MemberAccess

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Return to top
Show:
© 2016 Microsoft