Tlbexp.exe (Type Library Exporter)

The Type Library Exporter generates a type library that describes the types defined in a common language runtime assembly.

This tool is automatically installed with Visual Studio. To run the tool, use Visual Studio Developer Command Prompt or Visual Studio Developer PowerShell.

At the command prompt, type the following:

Syntax

tlbexp assemblyName [options]  

Parameters

Remarks

Tlbexp.exe generates a type library that contains definitions of the types defined in the assembly. Applications such as Visual Basic 6.0 can use the generated type library to bind to the .NET types defined in the assembly.

The entire assembly is converted at once. You cannot use Tlbexp.exe to generate type information for a subset of the types defined in an assembly.

You cannot use Tlbexp.exe to produce a type library from an assembly that was imported using the Type Library Importer (Tlbimp.exe). Instead, you should refer to the original type library that was imported with Tlbimp.exe. You can export a type library from an assembly that references assemblies that were imported using Tlbimp.exe. See the examples section below.

Tlbexp.exe places generated type libraries in the current working directory or the directory specified for the output file. A single assembly might cause several type libraries to be generated.

Tlbexp.exe generates a type library but does not register it. This is in contrast to the Assembly Registration tool (Regasm.exe), which both generates and registers a type library. To generate and register a type library with COM, use Regasm.exe.

If you do not specify either the /win32 or /win64 option, Tlbexp.exe generates a 32-bit or 64-bit type library that corresponds to the type of computer on which you are performing the compilation (32-bit or 64-bit computer). For cross-compilation purposes, you can use the /win64 option on a 32-bit computer to generate a 64-bit type library and you can use the /win32 option on a 64-bit computer to generate a 32-bit type library. In 32-bit type libraries, the SYSKIND value is set to SYS_WIN32. In 64-bit type libraries, the SYSKIND value is set to SYS_WIN64. All data type transformations (for example, pointer-sized data types such as IntPtr and UIntPtr) are converted appropriately.

If you use the MarshalAsAttribute attribute to specify a SafeArraySubType value of VT_UNKNOWN or VT_DISPATCH, Tlbexp.exe ignores any subsequent use of the SafeArrayUserDefinedSubType field. For example, given the following signatures:

[return:MarshalAs(UnmanagedType.SafeArray, SafeArraySubType=VarEnum.VT_UNKNOWN, SafeArrayUserDefinedSubType=typeof(ConsoleKeyInfo))] public Array StructUnkSafe(){return null;}  
[return:MarshalAs(UnmanagedType.SafeArray, SafeArraySubType=VarEnum.VT_DISPATCH, SafeArrayUserDefinedSubType=typeof(ConsoleKeyInfo))] public Array StructDispSafe(){return null;}  

the following type library is generated:

[id(0x60020004)]  
HRESULT StructUnkSafe([out, retval] SAFEARRAY(IUnknown*)* pRetVal);  
[id(0x60020005)]  
HRESULT StructDispSafe([out, retval] SAFEARRAY(IDispatch*)* pRetVal);  

Note that Tlbexp.exe ignores the SafeArrayUserDefinedSubType field.

Because type libraries cannot accommodate all the information found in assemblies, Tlbexp.exe might discard some data during the export process. For an explanation of the transformation process and identification of the source of each piece of information emitted to a type library, see the Assembly to Type Library Conversion Summary.

Note that the Type Library Exporter exports methods that have TypedReference parameters as VARIANT, even though the TypedReference object has no meaning in unmanaged code. When you export methods that have TypedReference parameters, the Type Library Exporter will not generate a warning or error and unmanaged code that uses the resulting type library will not run properly.

Examples

The following command generates a type library with the same name as the assembly found in myTest.dll.

tlbexp myTest.dll  

The following command generates a type library with the name clipper.tlb.

tlbexp myTest.dll /out:clipper.tlb  

The following example illustrates using Tlbexp.exe to export a type library from an assembly that references assemblies that were imported using Tlbimp.exe.

First use Tlbimp.exe to import the type library myLib.tlb and save it as myLib.dll.

tlbimp myLib.tlb /out:myLib.dll  

The following command uses the C# compiler to compile the Sample.dll, which references myLib.dll created in the previous example.

CSC Sample.cs /reference:myLib.dll /out:Sample.dll  

The following command generates a type library for Sample.dll that references myLib.dll.

tlbexp Sample.dll  

See also

• TypeLibExporterFlags
• Tools
• Regasm.exe (Assembly Registration Tool)
• Assembly to Type Library Conversion Summary
• Tlbimp.exe (Type Library Importer)
• Developer command-line shells