silverlight 操作串列埠資料的程式碼
阿新 • • 發佈:2019-02-08
串列埠PINVOKE程式碼,需要對超時時間進行設定,如果全為0,則是無限等待。而不是獲取不到退出。
public class SerialWrapper : IDisposable { #region Enum public enum StopBits { None, One, Two, OnePointFive, } public enum Parity { None, Odd, Even, Mark, Space, } #endregion #region Fields /// <summary> /// The baud rate at which the communications device operates. /// </summary> private readonly int iBaudRate; /// <summary> /// The number of bits in the bytes to be transmitted and received. /// </summary> private readonly byte byteSize; /// <summary> /// The system handle to the serial port connection ('file' handle). /// </summary> private IntPtr pHandle = IntPtr.Zero; /// <summary> /// The parity scheme to be used. /// </summary> private readonly Parity parity; /// <summary> /// The name of the serial port to connect to. /// </summary> private readonly string sPortName; /// <summary> /// The number of bits in the bytes to be transmitted and received. /// </summary> private readonly StopBits stopBits; #endregion #region Constructor /// <summary> /// Creates a new instance of SerialCom. /// </summary> /// <param>The name of the serial port to connect to</param> /// <param>The baud rate at which the communications device operates</param> /// <param>The number of stop bits to be used</param> /// <param>The parity scheme to be used</param> /// <param>The number of bits in the bytes to be transmitted and received</param> public SerialWrapper(string portName, int baudRate, StopBits stopBits, Parity parity, byte byteSize) { if (stopBits == StopBits.None) throw new ArgumentException("stopBits cannot be StopBits.None", "stopBits"); if (byteSize < 5 || byteSize > 8) throw new ArgumentOutOfRangeException("The number of data bits must be 5 to 8 bits.", "byteSize"); if (baudRate < 110 || baudRate > 256000) throw new ArgumentOutOfRangeException("Invalid baud rate specified.", "baudRate"); if ((byteSize == 5 && stopBits == StopBits.Two) || (stopBits == StopBits.OnePointFive && byteSize > 5)) throw new ArgumentException("The use of 5 data bits with 2 stop bits is an invalid combination, " + "as is 6, 7, or 8 data bits with 1.5 stop bits."); this.sPortName = portName; this.iBaudRate = baudRate; this.byteSize = byteSize; this.stopBits = stopBits; this.parity = parity; } /// <summary> /// Creates a new instance of SerialCom. /// </summary> /// <param>The name of the serial port to connect to</param> /// <param>The baud rate at which the communications device operates</param> /// <param>The number of stop bits to be used</param> /// <param>The parity scheme to be used</param> public SerialWrapper(string portName, int baudRate, StopBits stopBits, Parity parity) : this(portName, baudRate, stopBits, parity, 8) { } #endregion #region Open /// <summary> /// Opens and initializes the serial connection. /// </summary> /// <returns>Whether or not the operation succeeded</returns> public bool Open() { pHandle = CreateFile(this.sPortName, FileAccess.ReadWrite, FileShare.None, IntPtr.Zero, FileMode.Open, 0, IntPtr.Zero); if (pHandle == IntPtr.Zero) return false; if (ConfigureSerialPort()) return true; else { Dispose(); return false; } } #endregion #region Write /// <summary> /// Transmits the specified array of bytes. /// </summary> /// <param>The bytes to write</param> /// <returns>The number of bytes written (-1 if error)</returns> public int Write(byte[] data) { FailIfNotConnected(); if (data == null) return 0; int bytesWritten; if (WriteFile(pHandle, data, data.Length, out bytesWritten, 0)) return bytesWritten; return -1; } /// <summary> /// Transmits the specified string. /// </summary> /// <param>The string to write</param> /// <returns>The number of bytes written (-1 if error)</returns> public int Write(string data) { FailIfNotConnected(); // convert the string to bytes byte[] bytes; if (data == null) { bytes = null; } else { bytes = Encoding.UTF8.GetBytes(data); } return Write(bytes); } /// <summary> /// Transmits the specified string and appends the carriage return to the end /// if it does not exist. /// </summary> /// <remarks> /// Note that the string must end in '\r\n' before any serial device will interpret the data /// sent. For ease of programmability, this method should be used instead of Write() when you /// want to automatically execute the specified command string. /// </remarks> /// <param>The string to write</param> /// <returns>The number of bytes written (-1 if error)</returns> public int WriteLine(string data) { if (data != null && !data.EndsWith("\r\n")) data += "\r\n"; return Write(data); } #endregion #region Read /// <summary> /// Reads any bytes that have been received and writes them to the specified array. /// </summary> /// <param>The array to write the read data to</param> /// <returns>The number of bytes read (-1 if error)</returns> public int Read(byte[] data) { FailIfNotConnected(); if (data == null) return 0; int bytesRead; if (ReadFile(pHandle, data, data.Length, out bytesRead, 0)) return bytesRead; return -1; } /// <summary> /// Reads any data that has been received as a string. /// </summary> /// <param>The maximum number of bytes to read</param> /// <returns>The data received (null if no data)</returns> public string ReadString(int maxBytesToRead) { if (maxBytesToRead < 1) throw new ArgumentOutOfRangeException("maxBytesToRead"); byte[] bytes = new byte[maxBytesToRead]; int numBytes = Read(bytes); //string data = ASCIIEncoding.ASCII.GetString(bytes, 0, numBytes); string data = Encoding.UTF8.GetString(bytes, 0, numBytes); return data; } #endregion #region Dispose Utils /// <summary> /// Disconnects and disposes of the SerialCom instance. /// </summary> public void Dispose() { if (pHandle != IntPtr.Zero) { CloseHandle(pHandle); pHandle = IntPtr.Zero; } } /// <summary> /// Flushes the serial I/O buffers. /// </summary> /// <returns>Whether or not the operation succeeded</returns> public bool Flush() { FailIfNotConnected(); const int PURGE_RXCLEAR = 0x0008; // input buffer const int PURGE_TXCLEAR = 0x0004; // output buffer return PurgeComm(pHandle, PURGE_RXCLEAR | PURGE_TXCLEAR); } #endregion #region Private Helpers /// <summary> /// Configures the serial device based on the connection parameters pased in by the user. /// </summary> /// <returns>Whether or not the operation succeeded</returns> private bool ConfigureSerialPort() { DCB serialConfig = new DCB(); if (GetCommState(pHandle, ref serialConfig)) { // setup the DCB struct with the serial settings we need serialConfig.BaudRate = (uint)this.iBaudRate; serialConfig.ByteSize = this.byteSize; serialConfig.fBinary = 1; // must be true serialConfig.fDtrControl = 1; // DTR_CONTROL_ENABLE "Enables the DTR line when the device is opened and leaves it on." serialConfig.fAbortOnError = 0; // false serialConfig.fTXContinueOnXoff = 0; // false serialConfig.fParity = 1; // true so that the Parity member is looked at switch (this.parity) { case Parity.Even: serialConfig.Parity = 2; break; case Parity.Mark: serialConfig.Parity = 3; break; case Parity.Odd: serialConfig.Parity = 1; break; case Parity.Space: serialConfig.Parity = 4; break; case Parity.None: default: serialConfig.Parity = 0; break; } switch (this.stopBits) { case StopBits.One: serialConfig.StopBits = 0; break; case StopBits.OnePointFive: serialConfig.StopBits = 1; break; case StopBits.Two: serialConfig.StopBits = 2; break; case StopBits.None: default: throw new ArgumentException("stopBits cannot be StopBits.None"); } if (SetCommState(pHandle, ref serialConfig)) { // 串列埠連線超時設定 COMMTIMEOUTS timeouts = new COMMTIMEOUTS(); timeouts.ReadIntervalTimeout = 10; timeouts.ReadTotalTimeoutMultiplier = 10; timeouts.ReadTotalTimeoutConstant = 10; timeouts.WriteTotalTimeoutMultiplier = 0; timeouts.WriteTotalTimeoutConstant = 0; if (SetCommTimeouts(pHandle, ref timeouts)) { return true; } else { return false; } } else { return false; } } else { return false; } } /// <summary> /// Helper that throws a InvalidOperationException if we don't have a serial connection. /// </summary> private void FailIfNotConnected() { if (pHandle == IntPtr.Zero) throw new InvalidOperationException("You must be connected to the serial port before performing this operation."); } #endregion #region Native Helpers #region Native structures /// <summary> /// Contains the time-out parameters for a communications device. /// </summary> [StructLayout(LayoutKind.Sequential)] struct COMMTIMEOUTS { public uint ReadIntervalTimeout; public uint ReadTotalTimeoutMultiplier; public uint ReadTotalTimeoutConstant; public uint WriteTotalTimeoutMultiplier; public uint WriteTotalTimeoutConstant; } /// <summary> /// Defines the control setting for a serial communications device. /// </summary> [StructLayout(LayoutKind.Sequential)] struct DCB { public int DCBlength; public uint BaudRate; public uint Flags; public ushort wReserved; public ushort XonLim; public ushort XoffLim; public byte ByteSize; public byte Parity; public byte StopBits; public sbyte XonChar; public sbyte XoffChar; public sbyte ErrorChar; public sbyte EofChar; public sbyte EvtChar; public ushort wReserved1; public uint fBinary; public uint fParity; public uint fOutxCtsFlow; public uint fOutxDsrFlow; public uint fDtrControl; public uint fDsrSensitivity; public uint fTXContinueOnXoff; public uint fOutX; public uint fInX; public uint fErrorChar; public uint fNull; public uint fRtsControl; public uint fAbortOnError; } #endregion #region Native Methods // Used to get a handle to the serial port so that we can read/write to it. [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)] static extern IntPtr CreateFile(string fileName, [MarshalAs(UnmanagedType.U4)] FileAccess fileAccess, [MarshalAs(UnmanagedType.U4)] FileShare fileShare, IntPtr securityAttributes, [MarshalAs(UnmanagedType.U4)] FileMode creationDisposition, int flags, IntPtr template); // Used to close the handle to the serial port. [DllImport("kernel32.dll", SetLastError = true)] static extern bool CloseHandle(IntPtr hObject); // Used to get the state of the serial port so that we can configure it. [DllImport("kernel32.dll")] static extern bool GetCommState(IntPtr hFile, ref DCB lpDCB); // Used to configure the serial port. [DllImport("kernel32.dll")] static extern bool SetCommState(IntPtr hFile, [In] ref DCB lpDCB); // Used to set the connection timeouts on our serial connection. [DllImport("kernel32.dll", SetLastError = true)] static extern bool SetCommTimeouts(IntPtr hFile, ref COMMTIMEOUTS lpCommTimeouts); // Used to read bytes from the serial connection. [DllImport("kernel32.dll")] static extern bool ReadFile(IntPtr hFile, byte[] lpBuffer, int nNumberOfBytesToRead, out int lpNumberOfBytesRead, int lpOverlapped); // Used to write bytes to the serial connection. [DllImport("kernel32.dll", SetLastError = true)] static extern bool WriteFile(IntPtr hFile, byte[] lpBuffer, int nNumberOfBytesToWrite, out int lpNumberOfBytesWritten, int lpOverlapped); // Used to flush the I/O buffers. [DllImport("kernel32.dll", SetLastError = true)] static extern bool PurgeComm(IntPtr hFile, int dwFlags); #endregion #endregion }
呼叫程式碼:
serialPort = new SerialWrapper("com8", 14400, SerialWrapper.StopBits.One, SerialWrapper.Parity.None);
serialPort.Open();
string s = serialPort.ReadString(100);
this.ShowMessageBox(s);
serialPort.Dispose();