本文转自：

 

问：

I have the following code which needs the data to be read from port and then display in a textbox. I am using DataReceived event handler for this purpose but donot know how to display this data in textbox. From various sources i learnt that Invoke method should be used for this but donot know how to use it. Suggestions please...

private void Form1_Load(object sender, EventArgs e)    {        //SerialPort mySerialPort = new SerialPort("COM3");        mySerialPort.PortName = "COM3";        mySerialPort.BaudRate = 9600;        mySerialPort.Parity = Parity.None;        mySerialPort.StopBits = StopBits.One;        mySerialPort.DataBits = 8;        mySerialPort.Handshake = Handshake.None;        mySerialPort.DataReceived += new SerialDataReceivedEventHandler(mySerialPort_DataReceived);        mySerialPort.Open();    }    private void mySerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)    {        SerialPort sp = (SerialPort)sender;        string s= sp.ReadExisting();        // next i want to display the data in s in a textbox. textbox1.text=s gives a cross thread exception    }    private void button1_Click(object sender, EventArgs e)    {        mySerialPort.WriteLine("AT+CMGL=\"ALL\"");    } 答：

The MSDN contains a good  with examples about using control methods and properties from other threads.

In short, what you need is a delegate method that sets the Text property of your text box with a given string. You then call that delegate from within your mySerialPort_DataReceived handler via the TextBox.Invoke() method. Something like this:

public delegate void AddDataDelegate(String myString);public AddDataDelegate myDelegate;private void Form1_Load(object sender, EventArgs e){    //...    this.myDelegate = new AddDataDelegate(AddDataMethod);}public void AddDataMethod(String myString){    textbox1.AppendText(myString);}private void mySerialPort_DataReceived(object sender, SerialDataReceivedEventArgs e){   SerialPort sp = (SerialPort)sender;   string s= sp.ReadExisting();   textbox1.Invoke(this.myDelegate, new Object[] {s});       }