/// <summary>
/// frees all unmanaged memory assoicated with a DISPPARAMS structure
/// see https://msdn.microsoft.com/en-us/library/windows/desktop/ms221416(v=vs.85).aspx
/// </summary>
/// <param name="pDispParams"></param>
private static void UnprepareDispatchArgs(ComTypes.DISPPARAMS pDispParams)
{
if (pDispParams.rgvarg != IntPtr.Zero)
{
// free the array of COM VARIANTs
var variantStructSize = RdMarshal.SizeOf(typeof(VARIANT));
var variantArgsArrayOffset = pDispParams.rgvarg;
var argIndex = 0;
while (argIndex < pDispParams.cArgs)
{
VariantClear(variantArgsArrayOffset);
variantArgsArrayOffset += variantStructSize;
argIndex++;
}
RdMarshal.FreeHGlobal(pDispParams.rgvarg);
}
}
