How to properly show a bitmap in wpf Image control?

Question

I have a form with a ListBox containint a number of items. Each of the items is supposed to have a title and an image. Here's my XAML:

 <ListBox x:Name="MyList" HorizontalAlignment="Left" Height="384" Margin="10,505,0,0" VerticalAlignment="Top" Width="366"
        ItemsSource="{Binding}">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <StackPanel Orientation="Horizontal">
                    <!--This works:-->
                    <Label Content="{Binding Title}"/>
                    <!--This doesn't:-->
                    <Image Width="50" Height="50" Source="{Binding Cover}" Stretch="UniformToFill"/>
                </StackPanel>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>

My data class looks somewhat like this:

class Data
{
    public BitmapImage Cover{ get; set; }
    public string Title{ get; set; }
}

I'm getting the BitmapImage from a Bitmap like this:

Data data;//this is my data object
Bitmap bitmap;//this is my bitmap. It holds a valid image, I've checked.
MemoryStream memory = new MemoryStream();
bitmap.Save(memory, ImageFormat.Bmp);
memory.Position = 0;
data.Cover = new BitmapImage();
data.Cover.BeginInit();
data.Cover.StreamSource = memory;
data.Cover.CacheOption = BitmapCacheOption.OnLoad;
data.Cover.EndInit();

Finally, I set the list's data like this:

MyList.ItemsSource = dataList;//dataList is a List<Data>

Binding the title (or other simple properties like dates or int properties) to a Label works fine, however the image doesn't show up. How do I make it display properly?

Answer 1

So you Cover property in your Data class needs to raise a property changed event to let the view know it needs to get the image again as it has changed. To do this is simple:

class Data, INotifyPropertyChanged
{
     private BitmapImage _cover;
     public BitmapImage Cover
     {
        get { return _cover; }
        set 
        { 
            _cover = value;
            OnPropertyChanged("Cover");
        }
     }

    public string Title{ get; set; }

    public event PropertyChangedEventHandler PropertyChanged;
    protected virtual void OnPropertyChanged(string propertyName)
    {
        if (this.PropertyChanged != null)
        {
            this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

Answer 2

Your Cover init code is working fine in my project. I think you forgot to post the following line: dataList.Add(data); I don't know why you set the ItemsSource property twice. If you use MVVM and you bind the ItemsSource property, you shouldn't set that property from code ( MyList.ItemsSource = dataList;) Instead, I would suggest ItemsSource="{Binding} dataList" in the XAML.