WPF use a timer to repeat an action

Question

so I am new to WPF and am just trying to make a simple little program. When you hit a start button it will continuosly print fake code until you hit a stop button. I have tried to make it repeat until the stop button is hit 10 different ways but none of them are working. The TextBlock element will update once (or never) and then the whole program becomes unusable and the loading cursor comes up. I would guess that instead of going through a cycle, and then updating the TextBlocks, it is doing everything in the background and not updating visually.

 public partial class MainWindow : Window
{
    System.Windows.Threading.DispatcherTimer dispatcherTimer = new System.Windows.Threading.DispatcherTimer();

    Random r1 = new Random();

    bool stop = false;
    int numUse

    public MainWindow()
    {
        InitializeComponent();


        dispatcherTimer.Interval = new TimeSpan(0, 0, 1);
        dispatcherTimer.Start();

    }

    //Executes when the start button is hit, begins timer
    private void Button_Click(object sender, RoutedEventArgs e)
    {
        do
        {
            dispatcherTimer.Tick += dispatcherTimer_Tick;
        } while (stop == false);
    }

    //Executes when the stop button is hit, ends timers do while loop
    private void Button_Click_1(object sender, RoutedEventArgs e)
    {
        stop = true;
    }

    private void dispatcherTimer_Tick(object sender, EventArgs e)
    {

            numUse = r1.Next(1, 2);

            if (numUse == 1)
            {
                CodeBlock1.Text = "struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; ";
                CodeBlock2.Text = "";
                CodeBlock3.Text = "struct group_info *groups_alloc(int gidsetsize){ ";
                CodeBlock4.Text = "struct group_info *group_info; ";
                CodeBlock5.Text = "int nblocks; ";
                CodeBlock6.Text = "int i; ";
                CodeBlock7.Text = "";
                CodeBlock8.Text = "initialize stream";
            }
            else if (numUse == 2)
            {
                CodeBlock1.Text = "if (gidsetsize <= NGROUPS_SMALL) ";
                CodeBlock2.Text = "group_info->blocks[0] = group_info->small_block; ";
                CodeBlock3.Text = " else {  ";
                CodeBlock4.Text = " for (i = 0; i < nblocks; i++) { ";
                CodeBlock5.Text = "b = (void *)__get_free_page(GFP_USER);  ";
                CodeBlock6.Text = " goto out_undo_partial_alloc;  ";
                CodeBlock7.Text = "} ";
                CodeBlock8.Text = "";
            } else
            {

            }
    }



}

}

I have tried for loops, do while, using different methods in different orders. I understand that I likely messed up while going those routes so any method is ok for my purposes. Obviously I am using a Timer in this case.

Answer 1

It is not necessary to repeatedly call dispatcherTimer.Tick += dispatcherTimer_Tick in the while loop of Button_Click. I suspect that while this loop is running, nothing else on the message pump will run, including ticks from the DispatcherTimer.

You could probably do away with stop and merely act on the DispatcherTimer directly by calling Stop() from anywhere in the code.

Perhaps this instead:

public MainWindow()
{
    InitializeComponent();


    dispatcherTimer.Interval = new TimeSpan(0, 0, 1);
    dispatcherTimer.Tick += dispatcherTimer_Tick; // set it up here

}

 //Executes when the start button is hit, begins timer
private void Button_Click(object sender, RoutedEventArgs e)
{
    dispatcherTimer.Start(); // start timer

}

//Executes when the stop button is hit, ends timers do while loop
private void Button_Click_1(object sender, RoutedEventArgs e)
{
    dispatcherTimer.Stop(); // stop timer
}