How do you pass a BitmapImage from a background thread to the UI thread in WPF?

by

The following uses the dispatcher to execute an Action delegate on the UI thread. This uses a synchronous model, the alternate Dispatcher.BeginInvoke will execute the delegate asynchronously.

var backgroundThreadImage = GenerateImage(coordinate);

GeneratedImage.Dispatcher.Invoke(
        DispatcherPriority.Normal,
        new Action(() =>
            {
                GeneratedImage = backgroundThreadImage;
            }));

UPDATE
As discussed in the comments, the above alone will not work as the BitmapImage is not being created on the UI thread. If you have no intention of modifying the image once you have created it you can freeze it using Freezable.Freeze and then assign to GeneratedImage in the dispatcher delegate (the BitmapImage becomes read-only and thus threadsafe as a result of the Freeze). The other option would be to load the image into a MemoryStream on the background thread and then create the BitmapImage on the UI thread in the dispatcher delegate with that stream and the StreamSource property of BitmapImage.

More Related Contents:

  1. MVVM: Tutorial from start to finish?
  2. Good or bad practice for Dialogs in wpf with MVVM?
  3. How to bind to a PasswordBox in MVVM
  4. How to bind WPF button to a command in ViewModelBase?
  5. How do I bind a TabControl to a collection of ViewModels?
  6. Opening new window in MVVM WPF
  7. Bind to SelectedItems from DataGrid or ListBox in MVVM
  8. How to create a task (TPL) running a STA thread?
  9. How to implement a progress bar using the MVVM pattern
  10. Implementing CollectionChanged
  11. MVVM in WPF – How to alert ViewModel of changes in Model… or should I?
  12. WPF MVVM Why use ContentControl + DataTemplate Views rather than straight XAML Window Views?
  13. MVVM Light & WPF – Binding Multiple instances of a Window to a ViewModel
  14. Changing the View for a ViewModel
  15. Give some command to View in MVVM
  16. Can you access UI elements from another thread? (get not set)
  17. How to support ListBox SelectedItems binding with MVVM in a navigable application
  18. Error: Must create DependencySource on same Thread as the DependencyObject even by using Dispatcher
  19. WPF binding not updating the view
  20. WPF – Set Focus when a button is clicked – No Code Behind
  21. Twoway-bind view’s DependencyProperty to viewmodel’s property?
  22. WPF: How to bind a command to the ListBoxItem using MVVM?
  23. Can I somehow temporarily disable WPF data binding changes?
  24. The component does not have a resource identified by the uri
  25. ScrollIntoView for WPF DataGrid (MVVM)
  26. Binding Commands to Events?
  27. How to have multiple pairs “View-ViewModel”?
  28. Accessing a property in one ViewModel from another
  29. Add context menu in datagrid, how to get the select Item value
  30. Is it wrong to use the Dispatcher within my ViewModel?

Leave a Comment