The p/invoke declaration is wrong. It needs to be:
[DllImport("Rpcrt4.dll", CharSet = CharSet.Auto)]
public static extern int RpcMgmtEpEltInqNext(
IntPtr InquiryContext,
out RPC_IF_ID IfId,
out IntPtr Binding,
out Guid ObjectUuid,
out IntPtr Annotation
);
The first parameter must be passed by value.
You'll need to translate the RPC_IF_ID
struct. It's quite a simple one.
public struct RPC_IF_ID
{
public Guid Uuid;
public ushort VersMajor;
public ushort VersMinor;
}
The two string parameters you used were just wrong. They lead to the marshaller calling CoTaskMemFree
on the returned value for Annotation
. You don't want that. You will need to use Marshal.PtrToStringAnsi
to read the value.
Don't forget to call RpcBindingFree
and RpcStringFree
as per the docs.