Activator.CreateComInstanceFrom Method

Definition

Namespace:

System

Assembly:

mscorlib.dll

Creates an instance of the COM object whose name is specified.

Overloads

CreateComInstanceFrom(String, String)	Creates an instance of the COM object whose name is specified, using the named assembly file and the parameterless constructor.
CreateComInstanceFrom(String, String, Byte[], AssemblyHashAlgorithm)	Creates an instance of the COM object whose name is specified, using the named assembly file and the parameterless constructor.

CreateComInstanceFrom(String, String)

Creates an instance of the COM object whose name is specified, using the named assembly file and the parameterless constructor.

public:
 static System::Runtime::Remoting::ObjectHandle ^ CreateComInstanceFrom(System::String ^ assemblyName, System::String ^ typeName);

public static System.Runtime.Remoting.ObjectHandle CreateComInstanceFrom (string assemblyName, string typeName);

static member CreateComInstanceFrom : string * string -> System.Runtime.Remoting.ObjectHandle

Public Shared Function CreateComInstanceFrom (assemblyName As String, typeName As String) As ObjectHandle

Parameters

assemblyName

String

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

typeName

String

The name of the type to create an instance of.

Returns

ObjectHandle

A handle that must be unwrapped to access the newly created object, or null for Nullable<T> instances.

Exceptions

ArgumentNullException

typeName or assemblyName is null.

TypeLoadException

An instance cannot be created through COM.

-or-

typename was not found in assemblyName.

MissingMethodException

No matching constructor was found.

FileNotFoundException

assemblyName is not found, or the module you are trying to load does not specify a file name extension.

MemberAccessException

Cannot create an instance of an abstract class.

-or-

This member was invoked with a late-binding mechanism.

NotSupportedException

The caller cannot provide activation attributes for an object that does not inherit from MarshalByRefObject.

ArgumentException

assemblyName is the empty string ("").

Remarks

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

A System.Runtime.InteropServices.ComVisibleAttribute attribute with a value of true must be applied either explicitly or by default to the COM type so the CreateComInstanceFrom method can create an instance of that type; otherwise, TypeLoadException is thrown.

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

Note

Starting with .NET Framework 2.0, 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 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 .NET Framework 3.5 or later.

CreateComInstanceFrom(String, String, Byte[], AssemblyHashAlgorithm)

Creates an instance of the COM object whose name is specified, using the named assembly file and the parameterless constructor.

public:
 static System::Runtime::Remoting::ObjectHandle ^ CreateComInstanceFrom(System::String ^ assemblyName, System::String ^ typeName, cli::array <System::Byte> ^ hashValue, System::Configuration::Assemblies::AssemblyHashAlgorithm hashAlgorithm);

public static System.Runtime.Remoting.ObjectHandle CreateComInstanceFrom (string assemblyName, string typeName, byte[] hashValue, System.Configuration.Assemblies.AssemblyHashAlgorithm hashAlgorithm);

static member CreateComInstanceFrom : string * string * byte[] * System.Configuration.Assemblies.AssemblyHashAlgorithm -> System.Runtime.Remoting.ObjectHandle

Public Shared Function CreateComInstanceFrom (assemblyName As String, typeName As String, hashValue As Byte(), hashAlgorithm As AssemblyHashAlgorithm) As ObjectHandle

Parameters

assemblyName

String

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

typeName

String

The name of the type to create an instance of.

hashValue

Byte[]

The value of the computed hash code.

hashAlgorithm

AssemblyHashAlgorithm

The hash algorithm used for hashing files and generating the strong name.

Returns

ObjectHandle

A handle that must be unwrapped to access the newly created object, or null for Nullable<T> instances.

Exceptions

ArgumentNullException

typeName or assemblyName is null.

ArgumentException

assemblyName is the empty string ("").

PathTooLongException

An assembly or module was loaded twice with two different evidences.

-or-

assemblyName is longer than the system-defined maximum length.

FileNotFoundException

assemblyName is not found, or the module you are trying to load does not specify a file name extension.

FileLoadException

assemblyName is found but cannot be loaded.

BadImageFormatException

assemblyName is not a valid assembly.

SecurityException

A code base that does not start with "file://" was specified without the required WebPermission.

TypeLoadException

An instance cannot be created through COM.

-or-

typename was not found in assemblyName.

MissingMethodException

No matching constructor was found.

MemberAccessException

An instance of an abstract class cannot be created.

-or-

This member was invoked with a late-binding mechanism.

NotSupportedException

The caller cannot provide activation attributes for an object that does not inherit from MarshalByRefObject.

Remarks

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

A System.Runtime.InteropServices.ComVisibleAttribute attribute with a value of true must be applied either explicitly or by default to the COM type so the CreateComInstanceFrom method can create an instance of that type; otherwise, TypeLoadException is thrown.

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

Note

Starting with .NET Framework 2.0, 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 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 .NET Framework 3.5 or later.