List item can't be added from a different thread-CodePudding

I am practicing on networking using c#, everything's great so far I had a situation with a client/serv app where i was trying to send and receive a message and add the message in a ListBox in the server app. But after sending the message from the client, it shows me an error (cross-thread operation not valid) and i can't add the message to the list from another Thread Here's the code :

 public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        Thread serverListen = new Thread(bufferHandlerThread);
        serverListen.Start();
    }
    private void bufferHandlerThread()
    {
        UdpClient server = new UdpClient(6661);
        while (true)
        {
            IPEndPoint RemoteIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
            byte[] buffer = server.Receive(ref RemoteIpEndPoint);
            string receivedData = Encoding.UTF8.GetString(buffer);
            string toAdd = RemoteIpEndPoint.Address.ToString()   " <-> "   receivedData;
            dataList.Items.Add(toAdd); // Here the exception.
        }
    }
}

Thank you :)

CodePudding user response：

Replace this:

dataList.Items.Add(toAdd);

With:

this.Invoke(() =>
{
    dataList.Items.Add(toAdd);
});

CodePudding user response：

You can use the following methods.

public static void AddListItemThreadSafe<TControl>(this TControl @this, Action action)  where TControl : ListBox
{
    if (@this.InvokeRequired)
    {
        @this.Invoke((MethodInvoker)delegate
        {
            dataList.Items.Add(toAdd);

            action(); 
        });
    }
    else
    {
        action();
    }
}