Is there an OS function to translate a REFIID to a helpful name?

Question

Short of writing a function manually that translates a few known REFIID to names, such as:

if (riid == IID_IUnknown) return "IUnknown";
if (riid == IID_IShellBrowser) return "IShellBrowser";
...

Is there a system call that would return a reasonable debugging string for well-known (or even all) REFIIDs?

Answer 1

You can lookup the predefined interfaces in the HKCR\Interface registry subtree. Any component can register its interfaces there if it wishes. However this is not mandatory - the component might skip this registration.

Answer 2

Thanks for the responses. Below is what I came up with based on your feedback - much appreciated!

CString ToString(const GUID & guid)
{
 // could use StringFromIID() - but that requires managing an OLE string
 CString str;
 str.Format(_T("%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X"),
  guid.Data1,
  guid.Data2,
  guid.Data3,
  guid.Data4[0],
  guid.Data4[1],
  guid.Data4[2],
  guid.Data4[3],
  guid.Data4[4],
  guid.Data4[5],
  guid.Data4[6],
  guid.Data4[7]);
 return str;
}

CString GetNameOf(REFIID riid)
{
 CString name(ToString(riid));
 try
 {
  // attempt to lookup the interface name from the registry
  RegistryKey::OpenKey(HKEY_CLASSES_ROOT, "Interface", KEY_READ).OpenSubKey("{"+name+"}", KEY_READ).GetDefaultValue(name);
 }
 catch (...)
 {
  // use simple string representation if no registry entry found
 }
 return name;
}