C#使用WINDOWS API进行串口通讯的问题

Question

//打开串口
CreateFile("\\\\?\\" + FCommName, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, 0); //调用ReadFile时，程序阻塞，当有数据到达时，触发事件去读取
if (ReadFile(FCommHandle, FInputBuffer, FReadLength, ref FReadNumber, ref FOverlappedRead))
            {
                SetEvent(FOverlappedRead.hEvent);
                result = true;
                return;
            }//读取过程
 if (GetOverlappedResult(FCommHandle, FOverlappedRead, ref FReadNumber, false))
            {
                Buf = new byte[FReadNumber];                for (int I = 0; I <= FReadNumber - 1; I++)
                {
                    Buf[I] = FInputBuffer[I];                    
                }                Len = FReadNumber;
                //调用ReadFile，重新阻塞 
                SetupReadEvent();
                return result; 
            }//发送数据
WriteFile(FCommHandle, bArr, iLen, ref BytesWritten, ref FOverlappedWrite);现在的问题时，调用GetOverlappedResult时，提示读写受保护的内存。发送数据时，执行WriteFile时阻塞。有谁用过，谢谢。

Answer 1

FReadNumber 这个参数貌似应该用IntPtr

Answer 2

这是我用的
[DllImport("Kernel32.dll")]        private static extern bool ReadFile(            IntPtr hFile,            byte[] lpBuffer,            uint nNumberOfBytesToRead,            ref uint lpNumberOfBytesRead,            IntPtr lpOverlapped
            );

Answer 3

GetOverlappedResult 这个方法声明的时候第二个参数也要加上 ref 修饰，原函数这位置是结构指针