Progressbar for long running function WP7 C#

I am writing a sudoku solver app. The calculation time of the solver in certain cases can exceed 3 seconds, which would require a progress bar.

so my code:

private void solveButton_Click(object sender, RoutedEventArgs e)
{
    progressBar1.Visibility = Visibility.Visible;
    progressBar1.IsIndeterminate = true;
    mySolver.Solve(initialValue)
    progressBar1.Visilibity=Visilibity.collapsed;
    progressBar1.IsIndeterminate = false;
}

The code here is a condensed version of my actual code. This code doesn't work, as the progress bar does not appear at all. It seems to me that the UI updates only after event is finised executed. If I didn't hide the progressbar after the solver step, the progressBar appe开发者_C百科ars after the sudoku is solved. Replacing the solver with thread.sleep(1000) also results in the same UI update.

thanks for your help.

You should start the solver on a separate thread. That way the user interface thread can keep working on user interface objects even during the solving process, which allows your progress bar to be drawn on the screen and updated.

Problem is that your UI thread is not getting free in between to display the progress bar You need to use the background worker to solve the problem and in the main UI thread you should display the progress bar

  private void solveButton_Click(object sender, RoutedEventArgs e)
    {
       BackgroundWorker bg = new BackgroundWorker();
       bg.DoWork += new DoWorkEventHandler(DoWork);
       bg.RunWorkerCompleted += new RunWorkerCompletedEventHandler(bg_RunWorkerCompleted);
       bg.RunWorkerAsync(); 

       progressBar1.Visibility = Visibility.Visible;
       progressBar1.IsIndeterminate = true;         
    }

void DoWork(Object sender, DoWorkEventArgs args)
{
     mySolver.Solve(initialValue)
}

void bg_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs args)
{

    //  this method will be called once background worker has completed it's task
      progressBar1.Visilibity=Visilibity.collapsed;
      progressBar1.IsIndeterminate = false
}

Technically the code works fine, you just wrote the wrong code.

Your solver is running on the UI thread so it never has a chance to draw the progress bar before you hide it again. You need to spawn a thread (or use a background worker) to free up the UI thread so it can draw your progress bar.

I don't know too much about WP7 but with winforms if you have a long running function it needs to be run on a different thread than the UI.

Is BackgroundWorker available to you on WP7? you can update the bar on the ProgressChanged event and change the viability on the RunWorkerCompleted event

private void solveButton_Click(object sender, RoutedEventArgs e)
{
    progressBar1.Visibility = Visibility.Visible;
    progressBar1.IsIndeterminate = true;

    solveButton.Enabled = false; //I reccomend this so the button can't be pressed twice.

    BackgroundWoker bw = new BackgroundWorker();
    bw.RunWorkerCompleted += bw_RunWorkerCompleted;
    bw.DoWork += bw_DoWork;
    bw.ProgressChanged += bw_ProgressChanged;
    bw.RunWorkerAsync()

}

private void bw_DoWork(object sender, DoWorkEventArgs e)
{
    mySolver.Solve(initialValue, e)
}

private void bw_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    if(e.Error != null)
    {
         //Handle any exceptions that happened in the background worker.
    }
    progressBar1.Visilibity=Visilibity.collapsed;
    progressBar1.IsIndeterminate = false;
    solveButton.Enabled = true;
    ((IDisposable)sender).Dispose();
}

private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e)
{
    progressBar1.Value = e.ProgressPercentage;
}

//inside mySolver
void Solve(somthing initialValue, DoWorkEventArgs e)
{
    //Your solver work
    e.ReportProgress(progress); //a int from 0-100
    //more solver work
}

If you still want to run it on the UI Thread (which i wouldn't recommend!!) you can use the progressbar from the WP7 Toolkit that was released yesterday. It contains a progressbar that will work while your UI Thread is blocked.