You probably need to use the Marshal.GetDelegateForFunctionPointer
function
This takes an IntPtr
pointing to a native method and gives you back a delegate you can call.
public struct test
{
IntPtr API_GetUID;
IntPtr API_GetChipType;
}
[DllImport(@"GDevice.dll")]
public static extern void GetAPIObject(ref test test_a);
delegate void GetUID_Delegate(IntPtr pData, uint dataLen);
delegate uint GetChipType_Delegate();
test a = new test();
GetAPIObject(ref a);
GetUID_Delegate getUID = Marshal.GetDelegateForFunctionPointer<GetUID_Delegate>(a.API_GetUID);
GetChipType_Delegate getChipType = Marshal.GetDelegateForFunctionPointer<GetChipType_Delegate>(a.API_GetChipType);
uint chipType = getChipType();
Edit
Alternatively use UnmanagedFunctionPointerAttribute.
public struct test
{
GetUID_Delegate API_GetUID;
GetChipType_Delegate API_GetChipType;
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
delegate void GetUID_Delegate(IntPtr pData, uint dataLen);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
delegate uint GetChipType_Delegate();
}
[DllImport(@"GDevice.dll")]
public static extern void GetAPIObject(ref test test_a);
test a = new test();
GetAPIObject(ref a);
uint chipType = a.API_GetChipType();