僅當串口沒有被使用時纔將串口添加到comboBox！ C＃

Question

我在顯示可用串行端口的不同TabPages上有一些組合框。我可以在組合框中選擇一個端口並連接到它以獲取數據。現在我想讓comboBoxes隱藏已經在使用的端口。什麼是最好的方式來做到這一點？

這裏是一個組合框的下拉會發生什麼：

string[] portNames = SerialPort.GetPortNames(); 
    comboBox9.Items.Clear(); 
    foreach (var portName in portNames) 
    { 
     //checks if combox already contains same Item. 
     if (!comboBox9.Items.Contains(portNames)) 
     { 
      comboBox9.Items.Add(portName); 
     } 
    } 




    private void button1_Click(object sender, EventArgs e) 
    { 
     //<-- This block ensures that no exceptions happen 
     if (_serialPort1 != null && _serialPort1.IsOpen) 
      _serialPort1.Close(); 
     if (_serialPort1 != null) 
      _serialPort1.Dispose(); 
     //<-- End of Block 

     if (comboBox2.Text != "") 
     { 
      _serialPort1 = new SerialPort(comboBox2.Text, BaudRate, Parity.Even, 7, StopBits.Two);  //<-- Creates new SerialPort using the name selected in the combobox 
      _serialPort1.DataReceived += SerialPortOnDataReceived;  //<-- this event happens everytime when new data is received by the ComPort 

      _serialPort1.Open();  //<-- make the comport listen 

      button1.Enabled = false; 
      button2.Enabled = true; 

Answer 1

變化button_click事件如下。

private void button1_Click(object sender, EventArgs e) 
{ 
    //<-- This block ensures that no exceptions happen 
    if (_serialPort1 != null && _serialPort1.IsOpen) 
     _serialPort1.Close(); 
    if (_serialPort1 != null) 
     _serialPort1.Dispose(); 
    //<-- End of Block 
    // Adding port back to the comboBox as it is not open now. 
    comboBox.Items.Add(_serialPort1.PortName); 

    if (comboBox2.Text != "") 
    { 
     _serialPort1 = new SerialPort(comboBox2.Text, BaudRate, Parity.Even, 7, StopBits.Two);  //<-- Creates new SerialPort using the name selected in the combobox 
     _serialPort1.DataReceived += SerialPortOnDataReceived;  //<-- this event happens everytime when new data is received by the ComPort 

     _serialPort1.Open();  //<-- make the comport listen 

     //removing port from the comboBox as it is now open and in-use. 
     comboBox2.Items.Remove(comboBox2.Text); 
     button1.Enabled = false; 
     button2.Enabled = true; 
} 

這應該可以解決您的問題。