非常正确,我找了一下资料,
SUMMARY
When you are developing a class library, you may want Visual Studio .NET to list your library in the Add Reference dialog box on the .NET tab without the user having to browse for it.
This issue is not resolved if you install your assembly to the Global Assembly Cache (GAC), because the Add Reference dialog box is path-based and does not enumerate the components from the GAC.
To display your assembly in the Add Reference dialog box, you can add a registry key, such as the following, which points to the location of the assembly
[HKEY_CURRENT_USER\SOFTWARE\Microsoft\.NETFramework\AssemblyFolders\MyAssemblies]@="C:\\MyAssemblies"