How can a WPF application wait for windows to be fully opened by the UI thread before processing them?

Question

I need to build an application that opens complex windows (windows that take about 1 minute for the UI thread to open them). Then, once they are open and loaded, start generating images of these windows into .jpg files.

So naturally, my code first opens all the windows in a foreach loop, and then the code takes the snapshots in a tick event handler.

But the problem is that the code that starts taking the snapshots gets executed way before the windows are loaded. This is a job for code that plays with the UI thread, which I am not familiar with.

Here is my code:

protected override void DoStartCapture()
{
    try
    {
        m_dispatcherTimers = new List<DispatcherTimer>();

        foreach (var mimicGroup in m_mimicGroupsToCapture)
        {
            foreach (var mimic in mimicGroup.Mimics)
            {
                OpenView(mimic.View, 2);
            }

            var dispatcherTimer =
                new DispatcherTimer
                {
                    Interval = TimeSpan.FromSeconds(Convert.ToInt32(mimicGroup.CaptureIntervalInSeconds)),
                    Tag = mimicGroup
                };
            dispatcherTimer.Tick += M_mainDispatcherTimer_Tick;
            m_dispatcherTimers.Add(dispatcherTimer);
            dispatcherTimer.Start();
        }

        m_openViews = ViewsIntegrationService.GetOpenViews();
    }
    catch (Exception ex)
    {
        Trace.TraceError("View Capture Service error. Exception: " + ex.Message);
        StopCapture();
        throw;
    }
}

When I put a breakpoint on the line that declares the dispatcherTimer, that line gets hit before I see the windows. The OpenView method was written by someone else.

How can I modify this code so that it waits for all the views to be fully loaded by the UI thread?

Have you tried listening to the events of the windows, like the loaded event? — JonasH
– JonasH, Commented Feb 12 at 7:50

Louis van Tonder · Accepted Answer · 2025-02-12 08:18:56Z

1

Nest the capture method call in the ContentRendered event of each window?

private void MainWindow_ContentRendered(object sender, EventArgs e)
{
    DoStartCapture();
}

answered Feb 12 at 8:18

Louis van Tonder

3,7203 gold badges33 silver badges64 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How can a WPF application wait for windows to be fully opened by the UI thread before processing them?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related