Windows Mobile 打开串口失败
菜鸟提问：windows mobile6.1 打开串口的时候失败，用GetLastError看了一下返回值是6，百度到6对应的错误是：无效句柄。
有没有高手知道怎么回事。
代码如下：
调用：
CommPort cp = new CommPort();
cp.Open();
/// <summary>
/// 这是一个关于调用串口的类
/// </summary>
public class CommPort
{
public int PortNum = 1;
public int BaudRate = 9600;
public byte ByteSize = 8;
public byte Parity = 0; // 0-4=no,odd,even,mark,space
public byte StopBits = 0; // 0,1,2 = 1, 1.5, 2
public int ReadTimeout = 0;
//comm port win32 file handle
private int hComm = -1;
public bool Opened = false;
//win32 api constants
private const uint GENERIC_READ = 0x80000000;
private const uint GENERIC_WRITE = 0x40000000;
private const int OPEN_EXISTING = 3;
private const int INVALID_HANDLE_VALUE = -1;
[StructLayout(LayoutKind.Sequential)]
public struct DCB
{
//taken from c struct in platform sdk
public int DCBlength; // sizeof(DCB)
public int BaudRate; // current baud rate
/* these are the c struct bit fields, bit twiddle flag to set
public int fBinary; // binary mode, no EOF check
public int fParity; // enable parity checking
public int fOutxCtsFlow; // CTS output flow control
public int fOutxDsrFlow; // DSR output flow control
public int fDtrControl; // DTR flow control type
public int fDsrSensitivity; // DSR sensitivity
public int fTXContinueOnXoff; // XOFF continues Tx
public int fOutX; // XON/XOFF out flow control
public int fInX; // XON/XOFF in flow control
public int fErrorChar; // enable error replacement
public int fNull; // enable null stripping
public int fRtsControl; // RTS flow control
public int fAbortOnError; // abort on error
public int fDummy2; // reserved
*/
public uint flags;
public ushort wReserved; // not currently used
public ushort XonLim; // transmit XON threshold
public ushort XoffLim; // transmit XOFF threshold
public byte ByteSize; // number of bits/byte, 4-8
public byte Parity; // 0-4=no,odd,even,mark,space
public byte StopBits; // 0,1,2 = 1, 1.5, 2
public char XonChar; // Tx and Rx XON character
public char XoffChar; // Tx and Rx XOFF character
public char ErrorChar; // error replacement character
public char EofChar; // end of input character
public char EvtChar; // received event character
public ushort wReserved1; // reserved; do not use
}
[StructLayout(LayoutKind.Sequential)]
private struct COMMTIMEOUTS
{
public int ReadIntervalTimeout;
public int ReadTotalTimeoutMultiplier;
public int ReadTotalTimeoutConstant;
public int WriteTotalTimeoutMultiplier;
public int WriteTotalTimeoutConstant;
}
[StructLayout(LayoutKind.Sequential)]
private struct OVERLAPPED
{
public int Internal;
public int InternalHigh;
public int Offset;
public int OffsetHigh;
public int hEvent;
}
[DllImport("kernel32.dll ")]
private static extern int CreateFile(
string lpFileName, // file name
uint dwDesiredAccess, // access mode
int dwShareMode, // share mode
int lpSecurityAttributes, // SD
int dwCreationDisposition, // how to create
int dwFlagsAndAttributes, // file attributes
int hTemplateFile // handle to template file
);
[DllImport("kernel32.dll ")]
private static extern bool GetCommState(
int hFile, // handle to communications device
ref DCB lpDCB // device-control block
);
[DllImport("kernel32.dll ")]
private static extern bool BuildCommDCB(
string lpDef, // device-control string
ref DCB lpDCB // device-control block
);
[DllImport("kernel32.dll ")]
private static extern bool SetCommState(
int hFile, // handle to communications device
ref DCB lpDCB // device-control block
);
[DllImport("kernel32.dll ")]
private static extern bool GetCommTimeouts(
int hFile, // handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // time-out values
);
[DllImport("kernel32.dll ")]
private static extern bool SetCommTimeouts(
int hFile, // handle to comm device
ref COMMTIMEOUTS lpCommTimeouts // time-out values
);
[DllImport("kernel32.dll ")]
private static extern bool ReadFile(
int hFile, // handle to file
byte[] lpBuffer, // data buffer
int nNumberOfBytesToRead, // number of bytes to read
ref int lpNumberOfBytesRead, // number of bytes read
ref OVERLAPPED lpOverlapped // overlapped buffer
);
[DllImport("kernel32.dll ")]
private static extern bool WriteFile(
int hFile, // handle to file
byte[] lpBuffer, // data buffer
int nNumberOfBytesToWrite, // number of bytes to write
ref int lpNumberOfBytesWritten, // number of bytes written
ref OVERLAPPED lpOverlapped // overlapped buffer
);
[DllImport("kernel32.dll ")]
private static extern bool CloseHandle(
int hObject // handle to object
);
[DllImport("kernel32.dll ")]
private static extern uint GetLastError();
[解决办法]
CE 下要这样使用串口，例如：COM1：
WM 没用过。
[解决办法]
一、 首先保证你的代码没有逻辑错误，比如函数调用是不是穿得参数都对（最大可能的原因，比如C++， COM1: 你少写了冒号等等之类的。。。）
二、这个串口是不是在其他地方已经被打开了，如果打开了，没有关，那么这里你肯定是打不开的（很可能是这里的问题）
三、串口驱动是否加载上，看一下注册表active下面有没有你要打开串口的驱动（一般这里不会出问题）
如果这三条都没问题，那么你就要看看是不是硬件问题。
