AppDomain.CreateInstanceFrom Method (String, String, Object)
Assembly: mscorlib (in mscorlib.dll)
'Declaration Public Function CreateInstanceFrom ( _ assemblyFile As String, _ typeName As String, _ activationAttributes As Object() _ ) As ObjectHandle 'Usage Dim instance As AppDomain Dim assemblyFile As String Dim typeName As String Dim activationAttributes As Object() Dim returnValue As ObjectHandle returnValue = instance.CreateInstanceFrom(assemblyFile, typeName, activationAttributes)
public final ObjectHandle CreateInstanceFrom ( String assemblyFile, String typeName, Object activationAttributes )
public final function CreateInstanceFrom ( assemblyFile : String, typeName : String, activationAttributes : Object ) : ObjectHandle
The name, including the path, of a file that contains an assembly that defines the requested type. The assembly is loaded using the LoadFrom method.
The fully qualified name of the requested type, including the namespace but not the assembly, as returned by the Type.FullName property.
An array of one or more attributes that can participate in activation. Typically, an array that contains a single UrlAttribute object. The UrlAttribute specifies the URL that is required to activate a remote object. For a detailed description of client-activated objects, see Client Activation.
Return ValueAn object that is a wrapper for the new instance, or a null reference (Nothing in Visual Basic) if typeName is not found. The return value needs to be unwrapped to access the real object.
assemblyFile is a null reference (Nothing in Visual Basic).
assemblyFile was not found.
typeName was not found in assemblyFile.
The caller does not have sufficient permission to call this constructor.
No matching public constructor was found.
The caller cannot provide activation attributes for an object that does not inherit from MarshalByRefObject.
The operation is attempted on an unloaded application domain.
assemblyFile is not a valid assembly.
Version 2.0 or later of the common language runtime is currently loaded and assemblyFile was compiled with a later version.
An assembly or module was loaded twice with two different evidences.
This instance is a null reference (Nothing in Visual Basic).
The default constructor for typeName is invoked.
For more information, see the Activator.CreateInstanceFrom method.
When the CreateInstanceFrom method is used to create an instance in a target application domain, other than the application domain from which the call is made, the assembly is loaded in the target application domain. However, if the instance is unwrapped in the calling application domain, using the unwrapped instance in certain ways can cause the assembly to be loaded into the calling application domain. For example, after the instance is unwrapped, its type information might be requested, in order to call its methods late-bound. When the assembly is loaded into the calling application domain, exceptions can occur.
If another version of the same assembly was previously loaded into the calling application domain, or if the load path of the calling application domain is different from that of the target application domain, exceptions such as MissingMethodException can occur.
If the calling application domain makes early-bound calls to the instance type, InvalidCastException can be thrown when an attempt is made to cast the instance.
- FileIOPermissionAccess for the ability to access the location of the assembly. Associated enumeration: FileIOPermissionAccess.PathDiscovery
- FileIOPermissionAccess for the ability to read the file containing the assembly manifest. Associated enumeration: FileIOPermissionAccess.Read
- WebPermission for the ability to access the location of the assembly if the assembly is not local.
Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter EditionThe Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.