Updating Image.source from a separate thread in WPF

Question

I am building a WPF program that does some image acquisition, processing and displaying with a Image object. Currently I summon new a thread from c++ to do the acquisition and processing, then update the Image through callbacks.

It seems when I access the Image.source in the callback, it throws a exception of something like "cannot access this object because another thread own it". I tried to construct the Image and access the Image.source both in the STA thread but the same exception occurs. How should I deal with this?

Much appreciated.

See [this answer](https://stackoverflow.com/a/33917169) in particular, in the marked duplicate — Peter Duniho, Aug 28 '17 at 04:33

score 3 · Accepted Answer · answered Aug 26 '17 at 10:05

If you create an ImageSource on a background thread, you can call its Freeze method to make it cross-thread accessible.

You would then set the Source property of an Image control in the UI thread, by calling Dispacher.Invoke:

var bitmap = new BitmapImage();
bitmap.BeginInit();
...
bitmap.EndInit();
bitmap.Freeze();

image.Source.Dispatcher.Invoke(() => image.Source = bitmap);

Afnan Makhdoom · Answer 2 · 2017-08-26T09:11:50.817

-3

 if (InvokeRequired)
 {
    this.Invoke(new Action<source>(ImageObject), new object[] {value});
    return;
 }

OR

Invoke((MethodInvoker)delegate {
MainForm.UpdateImageSource(source); 
});

OR

Call Image.source = object

edited Aug 26 '17 at 09:11

answered Aug 26 '17 at 09:07

Afnan Makhdoom

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Sorry, what is "Call"? It does not look like a valid keyword in C#. – Jason M Aug 26 '17 at 09:10
that was the last resort, I am sorry, that is a vb.net keyword, try the options above it – Afnan Makhdoom Aug 26 '17 at 09:26
idk what objects and data youre dealing with as you did not publish any code. so I gave source and image object as ideas, fill in the appropriate data – Afnan Makhdoom Aug 26 '17 at 09:27

Updating Image.source from a separate thread in WPF

2 Answers2