/// <summary>
/// Look for typeinfo using IDispatch.GetTypeInfo
/// </summary>
/// <param name="dispatch"></param>
/// <param name="throwIfMissingExpectedTypeInfo">
/// Some COM objects just dont expose typeinfo. In these cases, this method will return null.
/// Some COM objects do intend to expose typeinfo, but may not be able to do so if the type-library is not properly
/// registered. This will be considered as acceptable or as an error condition depending on throwIfMissingExpectedTypeInfo</param>
/// <returns></returns>
internal static ComTypes.ITypeInfo GetITypeInfoFromIDispatch(IDispatch dispatch, bool throwIfMissingExpectedTypeInfo) {
uint typeCount;
int hresult = dispatch.TryGetTypeInfoCount(out typeCount);
Marshal.ThrowExceptionForHR(hresult);
Debug.Assert(typeCount <= 1);
if (typeCount == 0) {
return null;
}
IntPtr typeInfoPtr = IntPtr.Zero;
hresult = dispatch.TryGetTypeInfo(0, 0, out typeInfoPtr);
if (!ComHresults.IsSuccess(hresult)) {
CheckIfMissingTypeInfoIsExpected(hresult, throwIfMissingExpectedTypeInfo);
return null;
}
if (typeInfoPtr == IntPtr.Zero) { // be defensive against components that return IntPtr.Zero
if (throwIfMissingExpectedTypeInfo) {
Marshal.ThrowExceptionForHR(ComHresults.E_FAIL);
}
return null;
}
ComTypes.ITypeInfo typeInfo = null;
try {
typeInfo = Marshal.GetObjectForIUnknown(typeInfoPtr) as ComTypes.ITypeInfo;
} finally {
Marshal.Release(typeInfoPtr);
}
return typeInfo;
}
/// <summary>
/// Look for typeinfo using IDispatch.GetTypeInfo.
/// </summary>
/// <param name="dispatch"></param>
/// <param name="throwIfMissingExpectedTypeInfo">
/// Some COM objects just dont expose typeinfo. In these cases, this method will return null.
/// Some COM objects do intend to expose typeinfo, but may not be able to do so if the type-library is not properly
/// registered. This will be considered as acceptable or as an error condition depending on throwIfMissingExpectedTypeInfo</param>
/// <returns></returns>
internal static ComTypes.ITypeInfo GetITypeInfoFromIDispatch(IDispatch dispatch, bool throwIfMissingExpectedTypeInfo)
{
uint typeCount;
int hresult = dispatch.TryGetTypeInfoCount(out typeCount);
if ((hresult == ComHresults.E_NOTIMPL) || (hresult == ComHresults.E_NOINTERFACE))
{
return(null);
}
else
{
Marshal.ThrowExceptionForHR(hresult);
}
Debug.Assert(typeCount <= 1);
if (typeCount == 0)
{
return(null);
}
IntPtr typeInfoPtr = IntPtr.Zero;
hresult = dispatch.TryGetTypeInfo(0, 0, out typeInfoPtr);
if (!Utils.Succeeded(hresult))
{
CheckIfMissingTypeInfoIsExpected(hresult, throwIfMissingExpectedTypeInfo);
return(null);
}
if (typeInfoPtr == IntPtr.Zero)
{ // be defensive against components that return IntPtr.Zero
if (throwIfMissingExpectedTypeInfo)
{
Marshal.ThrowExceptionForHR(ComHresults.E_FAIL);
}
return(null);
}
ComTypes.ITypeInfo typeInfo = null;
try
{
typeInfo = Marshal.GetObjectForIUnknown(typeInfoPtr) as ComTypes.ITypeInfo;
}
finally
{
Marshal.Release(typeInfoPtr);
}
return(typeInfo);
}
