WPF - ObservableCollection

Question

I have an ObservableCollection in my CameraWindow where I'm manually capturing images from my usb webcam. This is my collection:

public ObservableCollection<BitmapImage> CameraWindowCapturedImages { get; } = new ObservableCollection<BitmapImage>();

and this is how I'm capturing images

void Cam_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
    try
    {
        System.Drawing.Image img = (Bitmap)eventArgs.Frame.Clone();
        MemoryStream ms = new MemoryStream();
        img.Save(ms, ImageFormat.Jpeg);
        ms.Seek(0, SeekOrigin.Begin);
        BitmapImage bi = new BitmapImage();
        bi.BeginInit();
        bi.StreamSource = ms;
        bi.EndInit();
        bi.Freeze();
        this.latestFrame = bi;
        Dispatcher.BeginInvoke(new ThreadStart(delegate
        {
            previewWindow.Source = bi;
        }));
    }
    catch (Exception ex)
    {
    }
}

private void manualCapture_Click(object sender, RoutedEventArgs e)
{
    if (captureImage != null)
    {
        captureImage(latestFrame);
    }
    Bitmap bm = BitmapImage2Bitmap(latestFrame);
    CapturedImages.Add(latestFrame);
}
private Bitmap BitmapImage2Bitmap(BitmapImage bitmapImage)
{
    using (MemoryStream outStream = new MemoryStream())
    {
        BitmapEncoder enc = new BmpBitmapEncoder();
        enc.Frames.Add(BitmapFrame.Create(bitmapImage));
        enc.Save(outStream);
        System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(outStream);

        return new Bitmap(bitmap);
    }
}

I also have ObservableCollection in my MainWindow

public ObservableCollection<BitmapImage> MainWindowCapturedImages { get; } = new ObservableCollection<BitmapImage>();

and I want to store manually captured images in my CameraWindow in my MainWindow's ObservableCollection.

Is this possible and if it is could someone please help me with that? Thanks!

You can assign/copy one observable collection to another. Where in code you are assigning/copying the required collections? And what are the hurdles in doing so? — Azaz ul Haq, Apr 26 '17 at 10:06
Are you asking on how to add the BitmapImage objects to the MainWindowCapturedImages Collection in your main window or what is your question? — mm8, Apr 26 '17 at 10:07
@mm8 asking on how to add the BitmapImage objects to the MainWindowCapturedImages Collection in my Mainwindow — , Apr 26 '17 at 10:08
I'm currently adding captured images to my `CameraWindowCapturedImages` using `Action captureImage;` in `manualCapture_Click` — , Apr 26 '17 at 10:12
As a note, during conversion from Bitmap to BitmapImage it might be more efficient to encode the bitmap as BMP instead of JPEG. See also [this question](http://stackoverflow.com/q/30727343/1136211) for potential improvement. — Clemens, Apr 26 '17 at 10:53

score 1 · Accepted Answer · answered Apr 26 '17 at 10:11

1

You need to get a reference to the window somehow. The easiest way to do this is probably to use the Application.Current.Windows collection:

MainWindow mainWindow = Application.Current.Windows.OfType<MainWindow>().FirstOrDefault();
if(mainWindow != null)
{
    mainWindow.MainWindowCapturedImages.Add(latestFrame);
}

answered Apr 26 '17 at 10:11

mm8

163,881
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where sould I add this? (sorry for asking stupid question, I'm very beginner c# / wpf) – Apr 26 '17 at 10:17
Perhaps in manualCapture_Click? Or wherver you want to be able to access the MainWindow. Only you know what you want to do... – mm8 Apr 26 '17 at 10:19
Please ask a new question if you have another issue. – mm8 Apr 26 '17 at 11:54

score 0 · Answer 2 · answered Apr 26 '17 at 10:23

0

The quick way to do this is(C# 6 and WPF):

(App.Current.MainWindow as MainWindow)?.Items.Add(image);

Also I wouldn't recommend doing it this way. You should use MVVM pattern which is a recommended developing technique for WPF apps

answered Apr 26 '17 at 10:23

SENya

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WPF - ObservableCollection

2 Answers2