private static ComTypes.ITypeInfo GetCoClassTypeInfo(object rcw, ComTypes.ITypeInfo typeInfo) {
Debug.Assert(typeInfo != null);
IProvideClassInfo provideClassInfo = rcw as IProvideClassInfo;
if (provideClassInfo != null) {
IntPtr typeInfoPtr = IntPtr.Zero;
try {
provideClassInfo.GetClassInfo(out typeInfoPtr);
if (typeInfoPtr != IntPtr.Zero) {
return Marshal.GetObjectForIUnknown(typeInfoPtr) as ComTypes.ITypeInfo;
}
} finally {
if (typeInfoPtr != IntPtr.Zero) {
Marshal.Release(typeInfoPtr);
}
}
}
// retrieving class information through IPCI has failed -
// we can try scanning the typelib to find the coclass
ComTypes.ITypeLib typeLib;
int typeInfoIndex;
typeInfo.GetContainingTypeLib(out typeLib, out typeInfoIndex);
string typeName = ComRuntimeHelpers.GetNameOfType(typeInfo);
ComTypeLibDesc typeLibDesc = ComTypeLibDesc.GetFromTypeLib(typeLib);
ComTypeClassDesc coclassDesc = typeLibDesc.GetCoClassForInterface(typeName);
if (coclassDesc == null) {
return null;
}
ComTypes.ITypeInfo typeInfoCoClass;
Guid coclassGuid = coclassDesc.Guid;
typeLib.GetTypeInfoOfGuid(ref coclassGuid, out typeInfoCoClass);
return typeInfoCoClass;
}