Implementing Single File Generators
A custom tool — sometimes referred to as a single file generator — can be used to extend the Visual Basic, Visual C#, and Visual J# project systems in Visual Studio. A custom tool is a COM component that implements theinterface. Using this interface, a custom tool transforms a single input file into a single output file. The result of the transformation may be source code, or any other output that is useful. Two examples of custom tool-generated code files are code generated in response to changes in a visual designer and files generated using Web Services Description Language (WSDL).
When a custom tool is loaded, or the input file is saved, the project system calls themethod, and passes a reference to a callback interface, whereby the tool can report its progress to the user.
The output file that the custom tool generates is added to the project with a dependency on the input file. The project system automatically determines the name of the output file, based on the string returned by the custom tool's implementation of.
A custom tool must implement the IVsSingleFileGenerator interface. Optionally, custom tools support theinterface to retrieve information from sources other than the input file. In any case, before you can use a custom tool, you must register it with the system or in the Visual Studio local registry. For more information on registering custom tools, see .