How to pass SAFEARRAY of UDTs to unmaged code from C#.
- by themilan
I also used VT_RECORD.
But didn't got success in passing safearray of UDTs.
[ComVisible(true)]
[StructLayout(LayoutKind.Sequential)]
public class MY_CLASS
{
[MarshalAs(UnmanagedType.U4)]
public Int32 width;
[MarshalAs(UnmanagedType.U4)]
public Int32 height;
};
[DllImport("mydll.dll")]
public static extern Int32 GetTypes(
[In, Out][MarshalAs(UnmanagedType.SafeArray, SafeArraySubType = VarEnum.VT_RECORD, SafeArrayUserDefinedSubType = typeof(MY_CLASS))]MY_CLASS[] myClass,
[In, Out][MarshalAs(UnmanagedType.SafeArray, SafeArraySubType = VarEnum.VT_RECORD, SafeArrayUserDefinedSubType = typeof(Guid))]Guid[] guids
);
If i communicate with my unmanaged code without 1st parameter, Then there is no error in passing "guids" parameter to unmanaged code.
I also able to cast elements of obtained SAFEARRAY at unmanaged side to GUID type.
But If i tried to pass my UDT class MY_CLASS to unmanaged code with SAFEARRAY then it fails on managed code. (as above code snippet)
It shows exception "An unhandled exception of type 'System.Runtime.InteropServices.SafeArrayTypeMismatchException' occurred in myapp.exe"
"Additional information: Specified array was not of the expected type."
Plz help me in such a situation to pass SAFEARRAY of UDTs to unmaged code.
