Windows Phone Images Grid "Out of memory" error

Question

I have "Out of memory" exception on windows phone when I try to display a grid of images. I played with code a little and think that Grid.Children.Add gives me that error.

I've made my custom class which shows gray rectangle and after an image was loaded, it shows the image instead of that rectangle. Here it is:

   class ImageWIthLoader
   {
     private BitmapImage m_loader_bitmap;
     private BitmapImage m_source_bitmap;
     private Image m_image;

     public Image image
     {
         get { return m_image; }
     }

     //url - url to 120x120 image; width, height = 120 both
     public ImageWIthLoader(string url, int width, int height)
     {
         m_image = new Image();

         m_loader_bitmap = new BitmapImage(new Uri("Assets/Images/image_await_background.png", Uri Kind.Relative));
         m_loader_bitmap.DecodePixelWidth = width;
         m_loader_bitmap.DecodePixelHeight = height;

         m_image.Source = m_loader_bitmap;

         m_source_bitmap = new BitmapImage(new Uri(url));
         m_source_bitmap.CreateOptions = BitmapCreateOptions.None;
         m_source_bitmap.ImageOpened += bitmapLoaded;
     }

     private void bitmapLoaded(object sender, RoutedEventArgs e)
     {
         m_image.Source = m_source_bitmap;
         m_loader_bitmap.UriSource = null;
     }
   }

And in another class I add these images to the grid (it's a series of them, loaded by url from a previously parsed json)

    private void addImageToGrid(ImageWIthLoader loader_image, int row, int col)
    {
        double margin = 0.05 * PIC_WIDTH;

        loader_image.image.SetValue(Grid.ColumnProperty, col);
        loader_image.image.SetValue(Grid.RowProperty, row);
        loader_image.image.Margin = new Thickness(margin);

        //comment out this string and everythins goes fine
        images_grid.Children.Add(loader_image.image);
    }

To guess some comments: I've made saving ImageWithLoader-s to List<> to prevent GC to collect them. ImageWithLoader url is an url of 120x120 images, so they must not be that heavy.

Part of XAML for the page with images grid:

       ....
        <ScrollViewer x:Name="scrollView" HorizontalAlignment="Left" Height="603" VerticalAlignment="Top" Width="456" >
            <Grid x:Name="images_grid" Height="596" Width="453"/>
        </ScrollViewer>
       ....

So, please, what am I doing wrong? Should I use another control instead of grid? Or there is something else I am missing?

P.S. Sorry for misinform. The size 120x120 is the displayed rectangle, the images loaded have sizes 800x800 (for example) and after that they are fit into 120x120 rectangle.

P.P.S. If I remove loading m_loader_bitmap, then pictures are displayed fine. m_loader_bitmap is 1px gray png

There are known memory leaks with BitmapImage, you can search google and SO for workarounds. — Chubosaurus Software, Nov 13 '14 at 01:39
Is there any other class but BitmapImage which I can use to show images? I am not releasing images, I keep them growin in number on scroll to the bottom of the page. Approx 100 pictures of 120x120 gives me Out Of Memory exception — Denis Kharitonov, Nov 13 '14 at 08:16

score 5 · Answer 1 · edited May 23 '17 at 11:50

5

Hi change this code like this

public void ImageWIthLoader(string url, int width, int height)
 {
      Deployment.Current.Dispatcher.BeginInvoke(() =>
        {
     m_image = new Image();

     m_loader_bitmap = new BitmapImage(new Uri("Assets/Images/image_await_background.png", UriKind.Relative));
     m_loader_bitmap.DecodePixelWidth = width;
     m_loader_bitmap.DecodePixelHeight = height;

     m_image.Source = m_loader_bitmap;

     m_loader_bitmap = null;

     m_source_bitmap = new BitmapImage(new Uri(url));
     m_source_bitmap.CreateOptions = BitmapCreateOptions.None;
     m_source_bitmap.ImageOpened += bitmapLoaded;
        });
 }

or find more from these link

Memory leak with BitmapImage

Memory consumption of BitmapImage/Image control in Windows Phone 8

WriteableBitmap Memory Leak

System.OutOfMemoryException

edited May 23 '17 at 11:50

Community

1
1

answered Nov 13 '14 at 06:02

Maulik Shah

673
7
19

nope. It didn't work. Still have crash. Memory profiler shows that approx 10 images take over 150 MB of memory. How come? BTW, sorry for misinform. The size of a single downloaded image is 800x800 and this image then is fit into 120x120 rect. – Denis Kharitonov Nov 14 '14 at 20:51
I have read somewhere that Windows Phone gives Max 150 MB to each application to run after that it will automatically close by system. If you want to display in just 120 X 120 then just change this lines m_loader_bitmap.DecodePixelWidth = 200; m_loader_bitmap.DecodePixelHeight = 200; – Maulik Shah Nov 15 '14 at 03:41
I didn't understand I need to change these two lines to what? Or I need to user a bigger rectangle? - 200x200 instead of 120x120? – Denis Kharitonov Nov 15 '14 at 18:17
no you need to change image height and width to 200 from 800 because you are displaying image in just 120 X 120 rectangle so decrease size of image – Maulik Shah Nov 17 '14 at 05:11

Windows Phone Images Grid "Out of memory" error

1 Answers1