/// <summary>
/// Gets the name of the default COM interface for this object.
/// </summary>
/// <remarks>
/// Uses the COM ITypeInfo interface to get the information. Does not throw.
/// </remarks>
/// <param name="obj"></param>
/// <returns>The name of the interface; null on any exception</returns>
///
internal static string GetDefaultCOMInterfaceName(object obj)
{
try {
string intfName = (string)Marshal.GetComObjectData(obj, "NETLinkCOMInterface");
if (intfName == null)
{
UCOMIDispatch iDisp = GetIDispatch(obj);
UCOMITypeInfo iTypeInfo = GetITypeInfo(obj, iDisp);
string typeLibName, docStr, helpFile;
int helpContext;
iTypeInfo.GetDocumentation(-1, out intfName, out docStr, out helpContext, out helpFile);
UCOMITypeLib iTypeLib;
int index;
iTypeInfo.GetContainingTypeLib(out iTypeLib, out index);
iTypeLib.GetDocumentation(-1, out typeLibName, out docStr, out helpContext, out helpFile);
intfName = typeLibName + "." + intfName;
Marshal.SetComObjectData(obj, "NETLinkCOMInterface", intfName);
// Not strictly necessary to release here, but better to force it now than rely on GC to do it later.
// Cannot release iDisp or iTypeInfo, as they might be cached in the object.
Marshal.ReleaseComObject(iTypeLib);
}
return(intfName);
} catch (Exception) {
return(null);
}
}
// Returns the index of this object's type in the typelib
protected int GetTypeLib(IntPtr dispPtr)
{
if (TraceUtil.If(this, TraceLevel.Info))
{
Trace.WriteLine("ComObjInfo::GetTypeLib: "
+ _obj + " type: " + _obj.GetType());
}
if (_typeLib != null)
{
return(-1);
}
UCOMITypeLib iTypeLib;
int index = -1;
try
{
IDispatch idisp = (IDispatch)
Marshal.GetObjectForIUnknown(dispPtr);
int count;
int result = idisp.GetTypeInfoCount(out count);
if (result != 0)
{
TraceUtil.WriteLineWarning
(typeof(ComObjectInfo),
"ComObjInfo - "
+ "GetTypeInfoCount failed: 0x"
+ result.ToString("x") + " obj: " + _obj);
throw new COMException("(probably a bug, please report) "
+ "Failed on GetTypeInfoCount",
result);
}
if (count == 0)
{
TraceUtil.WriteLineWarning
(typeof(ComObjectInfo),
"ComObjInfo - "
+ " typeinfo count = 0: " + _obj);
throw new Exception("This object has no type information "
+ "(GetTypeInfoCount returned 0). ");
}
result = idisp.GetTypeInfo(0, 0, out _typeInfo);
if (result != 0)
{
TraceUtil.WriteLineWarning(typeof(ComObjectInfo),
"ComObjInfo - "
+ "typeInfo not found:" + _obj);
throw new COMException("(probably a bug, please report) "
+ "Failed to get ITypeInfo",
result);
}
if (_typeInfo == null)
{
TraceUtil.WriteLineWarning(typeof(ComObjectInfo),
"ComObjInfo - "
+ "typeInfo not found:" + _obj);
throw new Exception("(probably a bug, please report) "
+ "Null TypeInfo pointer returned");
}
// Now we can get the type library information using these
// nice interfaces provided as part of the interop services
_typeInfo.GetContainingTypeLib(out iTypeLib, out index);
_typeLib = TypeLibrary.GetTypeLib(iTypeLib);
}
catch (Exception ex)
{
if (_typeInfo != null)
{
Guid guid = BasicInfo.GuidFromTypeInfo(_typeInfo);
TraceUtil.WriteLineWarning(typeof(ComObjectInfo),
"ComObjInfo (type "
+ guid + ")");
}
TraceUtil.WriteLineWarning(typeof(ComObjectInfo),
"Containing typelib not found:"
+ ex);
throw new Exception("Cannot get TypeLib for object. "
+ "Getting the TypeLib information for "
+ "an object is required as this contains "
+ "the type information used to display "
+ "the object. ", ex);
}
if (TraceUtil.If(this, TraceLevel.Info))
{
Trace.WriteLine("ComObjInfo - containing typelib index: "
+ index);
}
return(index);
}