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\"");
}
The MSDN contains a good article 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});
}
Try this (works for me):
private delegate void UpdateUiTextDelegate(string text);
private void Receive(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
if (mySerialPort.IsOpen)
{
RxString = mySerialPort.ReadLine();
Dispatcher.Invoke(DispatcherPriority.Send, new UpdateUiTextDelegate(DisplayText), RxString);
}
}
private void DisplayText(string RxString)
{
myTextBox.Text = RxString;
}
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