我有一个程序正在读取c＃中的串口。我需要快速写入端口，从中读取，然后关闭它。我不能把它打开。我知道串口缓慢读写，我试图将ReadTimeout和WriteTimeout属性设置为高，并添加了一个thread.Sleep来尝试拖动设备的读写时间。这里有一些代码：
我写入端口的方法：
private void CheckPorts(string testMessage)
{
foreach (string s in SerialPort.GetPortNames())
{
portNumber = Int32.Parse(s.Remove(0, 3));
testSerial = new SerialPort(s, baudRate, Parity.None, 8, StopBits.One);
if (testSerial.IsOpen)
{
testSerial.Close();
}
testSerial.ReadTimeout = 2000;
testSerial.WriteTimeout = 1000;
testSerial.Open();
if (testSerial.IsOpen)
{
string received;
testSerial.DiscardInBuffer();
try
{
//testSerial.DataReceived += new SerialDataReceivedEventHandler(testSerialPort_DataReceived);
testSerial.Write(testMessage);
System.Threading.Thread.Sleep(2000);
received = testSerial.ReadExisting(); //EITHER I USE THIS OR EVENT HANDLER, NOT BOTH
}
catch (TimeoutException e)
{
testSerial.Close();
continue;
}
if (received.Length > 0)
{
MessageReceived(received);
}
testSerial.Close();
}
}
}
private void testSerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
string received = testSerial.ReadExisting();
int y = received.IndexOf("\r");
while (y == -1)
{
received = received + testSerial.ReadExisting();
y = received.IndexOf("\r");
}
if (testSerial.IsOpen)
{
testSerial.Close();
}
}
我想知道，如果我必须使用数据处理程序，我如何保持串口打开足够长的时间来读取它，但是在下一个端口需要打开之前关闭串口？
看，第一个方法被调用几次，它遍历一个foreach循环，在几个端口上尝试消息，然后尝试读取响应。所以，在某些时候我必须关闭端口，否则下次它通过它，它不能正常工作，因为端口仍然是打开的
这是我的更新代码（仍未正常工作）：
private void CheckPorts(string testMessage, int baudRate)
{
foreach (string s in SerialPort.GetPortNames())
{
var interval = 3000; // ms
var timer = new System.Timers.Timer(interval);
timer.Elapsed += (o, e) =>
{
timer.Enabled = false;
if (testSerial.IsOpen)
testSerial.Close(); // may not be necessary with Dispose?
testSerial.Dispose();
timer.Dispose();
};
portNumber = Int32.Parse(s.Remove(0, 3));
testSerial = new SerialPort(s, baudRate, Parity.None, 8, StopBits.One);
testSerial.ReadTimeout = 2000;
testSerial.WriteTimeout = 2000;
if (testSerial.IsOpen)
{
testSerial.Close();
}
testSerial.Open();
timer.Enabled = true;
if (testSerial.IsOpen)
{
string received;
//testSerial.DiscardInBuffer();
//autoEvent = new AutoResetEvent(false);
try
{
// testSerial.DataReceived += new SerialDataReceivedEventHandler(testSerialPort_DataReceived);
// autoEvent.Reset();
lblPortNum.Content = s;
lblPortNum.Refresh();
testSerial.Write(testMessage);
//System.Threading.Thread.Sleep(2000);
//testSerial.NewLine = "\r\n";
byte[] rBuff = new byte[2];
int rCnt = testSerial.Read(rBuff, 0, 2);
System.Text.Encoding enc = System.Text.Encoding.ASCII;
received = enc.GetString(rBuff);
//received = testSerial.ReadLine();
}
catch (TimeoutException e)
{
testSerial.Close();
continue;
}
if (received.Length > 0)
{
MessageReceived(received, Int16.Parse(s.Remove(0, 3)));
}
/*
if (autoEvent.WaitOne(2000))
{
// the port responded
// testSerial.Close();
autoEvent.Dispose();
lblPortNum.Content = "HEY I RESPONDED";
}
else
{
testSerial.Close();
autoEvent.Dispose();
continue;
// port did not respond within 2 seconds
}*/
//testSerial.Close();
}
}
}
再次更新（仍然无法正常工作）
private void CheckPorts(string testMessage, int baudRate)
{
foreach (string s in SerialPort.GetPortNames())
{
portNumber = Int32.Parse(s.Remove(0, 3));
// MUST BE LOCAL
var serialOneOfMany = new SerialPort(s, baudRate, Parity.None, 8, StopBits.One);
serialOneOfMany.ReadTimeout = 2000;
serialOneOfMany.WriteTimeout = 2000;
if (serialOneOfMany.IsOpen)
{
serialOneOfMany.Close();
}
// timer must be defined _after_ serialOneOfMany
var interval = 3000; // ms
var timer = new System.Timers.Timer(interval);
timer.Elapsed += (o, e) =>
{
timer.Enabled = false;
if (serialOneOfMany.IsOpen)
serialOneOfMany.Close(); // may not be necessary with Dispose?
serialOneOfMany.Dispose();
timer.Dispose();
};
if (serialOneOfMany.IsOpen)
{
string received;
try
{
lblPortNum.Content = s;
lblPortNum.Refresh();
serialOneOfMany.Write(testMessage);
byte[] rBuff = new byte[2];
int rCnt = serialOneOfMany.Read(rBuff, 0, 2);
System.Text.Encoding enc = System.Text.Encoding.ASCII;
received = enc.GetString(rBuff);
}
catch (TimeoutException e)
{
serialOneOfMany.Close();
continue;
}
if (received.Length > 0)
{
CheckIfTheMessageMatches(received, Int16.Parse(s.Remove(0, 3)));
}
}
}
}
所以有了这个更新，它只是吹过代码，我可以逐行逐步执行代码，但它根本不会停止3秒。如果我在没有任何调试中断的情况下运行它，它只需要经过它一小段时间
更新10-25-11
private void CheckPorts(string testMessage, int baudRate)
{
foreach (string s in SerialPort.GetPortNames())
{
string received = "";
testSerial = new SerialPort(s,baudRate, Parity.None, 8, StopBits.One);
lblStatus.Content = "Scanning...";
lblStatus.Refresh();
if (testSerial.IsOpen)
{
testSerial.Close();
}
else
{
testSerial.Open();
}
if (testSerial.IsOpen)
{
try
{
testSerial.NewLine = "\r";
lblPortNum.Content = s;
lblPortNum.Refresh();
testSerial.WriteTimeout= 500;
testSerial.ReadTimeout = 1000;
testSerial.WriteLine(testMessage);
System.Threading.Thread.Sleep(500);
/*THIS DOESN'T WORK
byte[] buffer = new byte[testSerial.BytesToRead];
int rCnt = testSerial.Read(buffer, 0, buffer.Length);
received = enc.GetString(buffer);*/
//received = Convert.ToString(testSerial.BaseStream.Read(buffer, 0, (int)buffer.Length));
received = testSerial.ReadLine();
int y = received.IndexOf("\r");
while (y == -1)
{
received = received + testSerial.ReadExisting();
y = received.Length;
}
if (lblInfo.Dispatcher.Thread == Thread.CurrentThread)
{
CheckIfTheMessageMatches(received, s);
received = received + lblInfo.Content;
lblInfo.Content = received;
}
else
{
lblInfo.Dispatcher.Invoke(DispatcherPriority.Normal, new ThreadCheck(threadCheck), received);
}
if (testSerial.IsOpen)
{
testSerial.Close();
}
/*I USE THIS WITH THE sPort.Read() METHOD
while (rCnt > 0)
{
if (lblInfo.Dispatcher.Thread == Thread.CurrentThread)
{
CheckIfTheMessageMatches(received, s);
rCnt = 0;
received = received + lblInfo.Content;
lblInfo.Content = received;
}
else
{
lblInfo.Dispatcher.Invoke(DispatcherPriority.Normal, new ThreadCheck(threadCheck), received);
}
}
*/
if (testSerial.IsOpen)
{
testSerial.Close();
}
}
catch (TimeoutException e)
{
testSerial.Close();
continue;
}
received = null;
}
}
lblStatus.Content = "Finished Scanning.";
lblPortNum.Content = "";
}
更新的代码 这里有一些新的代码，仍然没有工作，dataeventhandler甚至没有调用过一次。我知道它正在收到消息，因为我有另一个与串行设备配合使用的程序
private void CheckPorts(string testMessage, int baudRate)
{
foreach (string s in SerialPort.GetPortNames())
{
var serialOneOfMany = new SerialPort(s, baudRate, Parity.None, 8, StopBits.One);
serialOneOfMany.ReadTimeout = 700;
serialOneOfMany.WriteTimeout = 100;
var interval = 500; // ms
var timer = new System.Timers.Timer(interval);
timer.Elapsed += (o, e) =>
{
timer.Enabled = false;
if (serialOneOfMany.IsOpen)
serialOneOfMany.Close(); // may not be necessary with Dispose?
serialOneOfMany.Dispose();
timer.Dispose();
};
timer.Enabled = true;
lblStatus.Content = "Scanning...";
lblStatus.Refresh();
if (serialOneOfMany.IsOpen)
{
serialOneOfMany.Close();
}
else
{
serialOneOfMany.Open();
}
if (serialOneOfMany.IsOpen)
{
string received;
try
{
lblPortNum.Content = s;
lblPortNum.Refresh();
serialOneOfMany.WriteLine(testMessage);
System.Threading.Thread.Sleep(400);
serialOneOfMany.DataReceived += new SerialDataReceivedEventHandler(testSerialPort_DataReceived);
}
catch (TimeoutException e)
{
serialOneOfMany.Close();
continue;
}
}
}
lblStatus.Content = "Finished Scanning.";
lblPortNum.Content = "";
}
private void testSerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
SerialPort receivingSerial = sender as SerialPort;
string received = receivingSerial.ReadExisting();
int y = received.IndexOf("\r");
while (y == -1)
{
received = received + receivingSerial.ReadExisting();
y = received.IndexOf("\r");
}
if (lblInfo.Dispatcher.Thread == Thread.CurrentThread)
{
string name = receivingSerial.PortName;
received = received + lblInfo.Content;
lblInfo.Content = received;
CheckIfTheMessageMatches(received, name);
}
else
{
lblInfo.Dispatcher.Invoke(DispatcherPriority.Normal, new ThreadCheck(threadCheck), received);
}
if (receivingSerial.IsOpen)
{
receivingSerial.Close();
}
}
答案 0 :(得分：4)
你应该能够同时做这些（假设没问题）。然后，当引发DataReceived事件（删除无关代码）时，您将关闭它们。只是不要关闭CheckPorts中的端口。
private void testSerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
SerialPort localSerialPort = sender as SerialPort;
... // use localSerialPort instead of global/class variable
if (localSerialPort.IsOpen)
{
localSerialPort.Close();
}
}
编辑：回应评论。
您可以随时添加计时器。如果你把它放在foreach循环中，你将获得一个定时器，用于在3秒后处理其给定串行端口的每个串行端口。在这里，重要的是在foreach循环中声明计时器。
var interval = 3000; // ms
var timer = new System.Timers.Timer(interval);
timer.Elapsed += (o,e) =>
{
timer.Enabled = false;
if (testSerial.IsOpen)
testSerial.Close(); // may not be necessary with Dispose?
testSerial.Dispose();
timer.Dispose();
}
timer.Enabled = true;
编辑：代码已更新，因此我将更新
范围对于我提供的代码非常重要。你应该摆脱非本地testSerial或在这里使用完全不同的名称。
portNumber = Int32.Parse(s.Remove(0, 3));
// MUST BE LOCAL
var serialOneOfMany = new SerialPort(s, baudRate, Parity.None, 8, StopBits.One);
serialOneOfMany.ReadTimeout = 2000;
serialOneOfMany.WriteTimeout = 2000;
if (serialOneOfMany.IsOpen)
{
serialOneOfMany.Close();
}
// timer must be defined _after_ serialOneOfMany
var interval = 3000; // ms
var timer = new System.Timers.Timer(interval);
timer.Elapsed += (o, e) =>
{
timer.Enabled = false;
if (serialOneOfMany.IsOpen)
serialOneOfMany.Close(); // may not be necessary with Dispose?
serialOneOfMany.Dispose();
timer.Dispose();
};
答案 1 :(得分：1)
从Microsoft查看此信息：
此方法以字符串形式返回SerialPort对象的流和内部缓冲区的内容。此方法不使用超时。请注意，此方法可以在内部缓冲区中留下尾随前导字节，这会使BytesToRead值大于零。
为什么不使用通常的Read方法SerialPort.Read (Byte[], Int32, Int32)
答案 2 :(得分：1)
请看一下（我还在answer中使用了darthwillard提出的串口相关问题）。所有端口一个接一个地打开，DataReceived事件被绑定（您需要做的就是测试传入消息），但不需要等待。计时器事件处理程序可以关闭所有端口或保留您想要使用的端口等。我希望它有所帮助！
private List<SerialPort> openPorts = new List<SerialPort>();
private void button3_Click(object sender, EventArgs e)
{
int baudRate = 9600;
string testMessage = "test";
txtPortName.Text = "Testing all serial ports";
foreach (string s in SerialPort.GetPortNames())
{
SerialPort newPort = new SerialPort(s, baudRate, Parity.None, 8, StopBits.One);
if (!newPort.IsOpen)
{
try
{
newPort.Open();
}
catch { }
}
if (newPort.IsOpen)
{
openPorts.Add(newPort);
newPort.DataReceived += new SerialDataReceivedEventHandler(serialOneOfMany_DataReceived);
newPort.Write(testMessage);
}
else
{
newPort.Dispose();
}
}
txtPortName.Text = "Waiting for response";
tmrPortTest.Enabled = true;
}
private void serialOneOfMany_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
txtPortName.Text = ((SerialPort)sender).PortName;
}
private void tmrPortTest_Tick(object sender, EventArgs e)
{
tmrPortTest.Enabled = false;
foreach (SerialPort port in openPorts)
{
if (port.PortName != txtPortName.Text)
{
port.Close();
port.Dispose();
}
}
}
答案 3 :(得分：0)
在写入端口之前尝试设置事件处理程序，然后查看它是否没有捕获到您的断点。
答案 4 :(得分：0)
您无法使用Thread.Sleep。它阻止从设备读取。你需要产生一个新的线程。
答案 5 :(得分：0)
BackgroundWorker你最好。例如：
BackgroundWorker worker=new BackgroundWorker();
worker.DoWork += (s, dwe) =>
{
// do your serial IO here
worker.RunWorkerCompleted += (s, rwe) =>
{
// check for rwe.Error and respond
};
worker.RunWorkerAsync();
答案 6 :(得分：-1)
以公共形式打开端口1 就在InitializeComponent（）之后/之下; myport.open 并关闭收到的数据。 成功了！