ImportedFromTypeLibAttribute Class
 
System_CAPS_noteNote

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Indicates that the types defined within an assembly were originally defined in a type library.

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

SystemObject
   SystemAttribute
    System.Runtime.InteropServicesImportedFromTypeLibAttribute

[AttributeUsageAttribute(AttributeTargets.Assembly, Inherited = false)]
[ComVisibleAttribute(true)]
public sealed class ImportedFromTypeLibAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Assembly, Inherited = false)]
[ComVisibleAttribute(true)]
public ref class ImportedFromTypeLibAttribute sealed : Attribute
[<Sealed>]
[<AttributeUsageAttribute(AttributeTargets.Assembly, Inherited = false)>]
[<ComVisibleAttribute(true)>]
type ImportedFromTypeLibAttribute = 
    class
        inherit Attribute
    end
<AttributeUsageAttribute(AttributeTargets.Assembly, Inherited := False)>
<ComVisibleAttribute(True)>
Public NotInheritable Class ImportedFromTypeLibAttribute
	Inherits Attribute
NameDescription
System_CAPS_pubmethod ImportedFromTypeLibAttribute

Initializes a new instance of the ImportedFromTypeLibAttribute class with the name of the original type library file.

NameDescription
System_CAPS_pubproperty

When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)

System_CAPS_pubproperty

Gets the name of the original type library file.

NameDescription
System_CAPS_pubmethod Equals

This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)

System_CAPS_pubmethod GetHashCode

Returns the hash code for this instance.(Inherited from Attribute.)

System_CAPS_pubmethod GetType

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethod IsDefaultAttribute

When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)

System_CAPS_pubmethod Match

When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)

System_CAPS_pubmethod ToString

Returns a string that represents the current object.(Inherited from Object.)

NameDescription
System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetIDsOfNames

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfo

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeGetTypeInfoCount

Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterface System_CAPS_privmethod _AttributeInvoke

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

You can apply this attribute to assemblies, although the Tlbimp.exe (Type Library Importer) typically applies it for you when it a type library.

The primary use of the attribute is to capture the original source of the type information. For example, you can import A.tlb as an interop assembly called A.dll and have assembly B.dll reference A.dll. When you export B.dll to B.tlb, this attribute causes the references in B.tlb that point to A.dll to point instead to A.tlb. This should not be confused with the ComImportAttribute, which specifies that an individual type is implemented in COM.

using System;
using System.Reflection;
using System.Runtime.InteropServices;

namespace A
{
	class ClassA
	{
		public static bool IsCOMAssembly( Assembly a )
		{
			object[] AsmAttributes = a.GetCustomAttributes( typeof( ImportedFromTypeLibAttribute ), true );
			if( AsmAttributes.Length > 0 )
			{
				ImportedFromTypeLibAttribute imptlb = ( ImportedFromTypeLibAttribute )AsmAttributes[0];
				string strImportedFrom  = imptlb.Value;

				// Print out the the name of the DLL from which the assembly is imported.
				Console.WriteLine( "Assembly " + a.FullName + " is imported from " + strImportedFrom );

				return true;
			}  
			// This is not a COM assembly.
			Console.WriteLine( "Assembly " + a.FullName + " is not imported from COM" );
			return false;
		}
	}
}
Imports System
Imports System.Reflection
Imports System.Runtime.InteropServices

Module A
	Public Function IsCOMAssembly(ByVal a As System.Reflection.Assembly) As Boolean

		Dim AsmAttributes As Object() = a.GetCustomAttributes(GetType(ImportedFromTypeLibAttribute), True)
		If AsmAttributes.Length = 1 Then
			Dim imptlb As ImportedFromTypeLibAttribute = AsmAttributes(0)
			Dim strImportedFrom As String = imptlb.Value

			' Print out the the name of the DLL from which the assembly is imported.
			Console.WriteLine("Assembly " + a.FullName + " is imported from " + strImportedFrom)

			Return True
		End If

		' This is not a COM assembly.
		Console.WriteLine("Assembly " + a.FullName + " is not imported from COM")

		Return False
	End Function
End Module
using namespace System;
using namespace System::Reflection;
using namespace System::Runtime::InteropServices;

class ClassA
{
private:
   static bool IsCOMAssembly( Assembly^ a )
   {
      array<Object^>^AsmAttributes = a->GetCustomAttributes( ImportedFromTypeLibAttribute::typeid, true );
      if ( AsmAttributes->Length > 0 )
      {
         ImportedFromTypeLibAttribute^ imptlb = dynamic_cast<ImportedFromTypeLibAttribute^>(AsmAttributes[ 0 ]);
         String^ strImportedFrom = imptlb->Value;

         // Print out the name of the DLL from which the assembly is imported.
         Console::WriteLine( "Assembly {0} is imported from {1}", a->FullName, strImportedFrom );
         return true;
      }

      // This is not a COM assembly.
      Console::WriteLine( "Assembly {0} is not imported from COM", a->FullName );
      return false;
   }
};
.NET Framework
Available since 1.1

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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