Problems with IMetaDataImport::ResolveTypeRef Meth

问题:

I have my own debugger for .NET apps that uses IMetaDataImport interface

When I call ResolveTypeRef method, I always get NotImplementedException.

The definition of ResolveTypeRef is like this:

[ComImport]
[Guid("....")] //a valid GUID
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
[CLSCompliant(false)]
public interface IMetaDataImport {
  void ResolveTypeRef(
    [ComAliasName("mdTypeRef")] mdToken tr,
    [ComAliasName("REFIID")] ref Guid riid,
    [ComAliasName("IUnknown**"), Out, MarshalAs(UnmanagedType.IUnknown)] out object ppIScope,
    [ComAliasName("mdTypeDef*"), Out] out mdToken ptd
  );
  // ... other methods from IMetaDataImport
}

The method calling:

metadataImport.ResolveTypeRef(typeRefToken, ref metadataImportGuid, out metadataObject, out typeDefToken)

Typically, the method should resolve type System.Exception or System.SystemException.

The problem occured when I moved app from .NET 3.5 to .NET 4.

Thanks for the answers!

回答1:

Uff, I finally get rid of this ... The solution is not call ResolveTypeRef, but create your own method to resolve type:

  mdToken ptkResScope;
  uint len;
  metadataImport.GetTypeRefProps(typeRef, out ptkResScope, null, 0, out len);
  StringBuilder sb = new StringBuilder((int)len);
  metadataImport.GetTypeRefProps(typeRef, out ptkResScope, sb, len, out len);
  string className = sb.ToString();
  foreach (loadedModule ) {   // this is quite tricky part ...     
    metadataImportForLoadedModule = GetMetaDataImportForModule(loadedModule);
    metadataImportForLoadedModule.FindTypeDefByName(className, mdToken.Nil, out typeDef);
    if ( typeDef.IsNonNil(CorTokenType.mdtTypeDef) ) {
      return typeDef;
      }
    }

The idea comes from David Broman's CLR Profiling API Blog: Metadata Tokens, Run-Time IDs, and Type Loading (really good reading if you are interested in MetaDataImport).