Why program crashes by adding a lot of images to listview?

Question

This is my XAML:

Answer 1

You could have a view model that loads thumbnail image files asynchronously, and also limits their size by setting the DecodePixelWidth or DecodePixelHeight property.

public class ImageData
{
    public string Name { get; set; }
    public ImageSource ImageSource { get; set; }
}

public class ViewModel
{
    public ObservableCollection Images { get; }
        = new ObservableCollection();

    public async Task LoadFolder(string folderName, string extension = "*.jpg")
    {
        Images.Clear();

        foreach (var path in Directory.EnumerateFiles(folderName, extension))
        {
            Images.Add(new ImageData
            {
                Name = Path.GetFileName(path),
                ImageSource = await LoadImage(path)
            });
        }
    }

    public Task LoadImage(string path)
    {
        return Task.Run(() =>
        {
            var bitmap = new BitmapImage();

            using (var stream = new FileStream(path, FileMode.Open, FileAccess.Read))
            {
                bitmap.BeginInit();
                bitmap.DecodePixelHeight = 100;
                bitmap.CacheOption = BitmapCacheOption.OnLoad;
                bitmap.StreamSource = stream;
                bitmap.EndInit();
                bitmap.Freeze();
            }

            return bitmap;
        });
    }
}

You would bind to such a view model like this:

    

...

    
        
            
        
    
    
        
            
                
                    
                    
                
                
                
            
        
    

And populate it e.g. in some async input event handler, like:

private async void Button_Click(object sender, RoutedEventArgs e)
{
    await ((ViewModel)DataContext).LoadFolder(...);
}