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Activator.CreateInstanceFrom Method (String, String)

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

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

public static ObjectHandle CreateInstanceFrom (
	string assemblyFile,
	string typeName
)
public static ObjectHandle CreateInstanceFrom (
	String assemblyFile, 
	String typeName
)
public static function CreateInstanceFrom (
	assemblyFile : String, 
	typeName : String
) : ObjectHandle

Parameters

assemblyFile

The name of a file that contains an assembly where the type named typeName is sought.

typeName

The name of the preferred type.

Return Value

A handle that must be unwrapped to access the newly created instance.

Exception typeCondition

ArgumentNullException

typeName is a null reference (Nothing in Visual Basic).

MissingMethodException

No matching public constructor was found.

TypeLoadException

typename was not found in assemblyFile.

FileNotFoundException

assemblyFile was not found.

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.

TargetInvocationException

The constructor, which was invoked through reflection, threw an exception.

SecurityException

The caller does have the required FileIOPermission.

Use the ObjectHandle.Unwrap method to unwrap the return value.

For information about other exceptions that can be thrown by invoked methods, see the Exceptions section of the Assembly.LoadFrom and CreateInstance methods.

The following code example demonstrates calling the CreateInstanceFrom method. This code example is part of a larger example provided for the Activator class.

' Create an instance of the SomeType class that is defined in this assembly.
Dim oh As Runtime.Remoting.ObjectHandle = _
    Activator.CreateInstanceFrom(Assembly.GetEntryAssembly().CodeBase, GetType(SomeType).FullName)

' Call an instance method defined by the SomeType type using this object.
Dim st As SomeType = CType(oh.Unwrap, SomeType)
st.DoSomething(5)

  • SecurityPermission  for the ability to call unmanaged code when creating an instance of a delegate. Associated enumeration: SecurityPermissionFlag/UnmanagedCode
  • ReflectionPermission  for the ability to invoke operations on all type members. Associated enumeration: ReflectionPermissionFlag/MemberAccess
  • FileIOPermission  for the ability to search directory paths and read their contents. Associated enumerations: FileIOPermissionAccess/PathDiscovery and Read

Windows 98, Windows 2000 SP4, Windows Millennium Edition, 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

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