求救,USB 写入问题?

我和到如下代码,但是返回结果总是等于0,各位弟兄帮帮兄弟下,万分感谢!
 
            int NumberOfBytesWritten = 0;
            int Result;
            bool Success = false;                
            byte[] outputReportBuffer; 
                
            outputReportBuffer = new byte[2];
            // outputReportBuffer[4] = 0040;
            outputReportBuffer[0] = 0x02;
            Result = FileIOApiDeclarations.WriteFile(_HIDHandle, ref outputReportBuffer[0],        outputReportBuffer.Length, ref NumberOfBytesWritten, 0);
            Debug.Write("outputReportBuffer=" + Result);