Question

I am trying to build a small application that logins into a server and gathers data from it constantly. The problem that I am having is that my GUI is slow to respond even when using either background worker or a thread. When my application tries to login into the server, I see “(Not Responding)” appear in my login form, but it logins in few seconds later without Windows giving the “The program has stopped responding… terminate application” dialog. When I click the start button on my application I noticed by GUI becomes very sluggish and unresponsive. I was wondering how I could improve the response time of my program. Here is the code for the Login form using a background worker and the code for my thread that gathers data from the server. I apologize for the last section of the code not being format correctly, but SO is being non-cooperative.

    private void btnLogin_Click(object sender, EventArgs e)
    {
        if (string.IsNullOrEmpty(txtAccount.Text) || string.IsNullOrEmpty(txtPassword.Text))
        {
            MessageBox.Show("Must Enter Username and Password");
            return;
        }
        btnLogin.Enabled = false;
        account = txtAccount.Text;
        password = txtPassword.Text;
        accountType = cmbAccountType.SelectedItem.ToString();
        loginBackgroundWorker.RunWorkerAsync();
    }

    private void loginBackgroundWorker_DoWork(object sender, DoWorkEventArgs e)
    {
        loginSuccess=tradingDesk.Login(account, password, accountType);
    }

    private void loginBackgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        if (loginSuccess)
        {
            this.DialogResult = DialogResult.OK;
        }
        btnLogin.Enabled = true;
    }


    private void btnStart_Click(object sender, EventArgs e)
        {
        Thread dataThread=new Thread(GetServerData);
        dataThread.IsBackground=true;

        try
        {
            dataThread.Start();
        }
        catch(Exception ex)
        {
            MessageBox.Show(ex.Message);
        }}

private void GetServerData()
{
    try
    {
        while (true)
        {
            lock (myLock)
            {
               //Perform Server Task with large amounts of data
            }
        }
    }
    catch
    {
        //Handle exception code
    }
}

Answer 1

Try using BackgroundWorker for your processing – easier than handling threads yourself unless you’re in the business of handling threads in a pool and you like that stuff (or you’ve been doing it like that since v1.0 as I have – you’re just used to it that way).

I also put all my UI interactions into a background thread and marshall the calls back through to the UI thread. This article should help you out on both: Tools for Updating Windows Forms UI from Background Threads

Another test is to swap out your call to tradingDesk.Login with a simple sleep to see if that changes anything. And how’s your CPU? Happen to notice if the thread or process spikes in CPU usage? Even a multi-threaded app that eats up all your CPU will stutter – Flash comes to mind – slows down my entire system even other processes.