Data binding the TextBlock.Inlines

will picture will · Dec 24, 2009 · Viewed 21.4k times · Source

My WPF App receives a stream of messages from a backend service that I need to display in the UI. These messages vary widely and I want to have different visual layout (string formats, colors, Fonts, icons, whatever etc.) for each message.

I was hoping to just be able to create an inline (Run, TextBlock, Italic etc) for each message then somehow put them all in a ObservableCollection<> and using he magic of WPF Data Binding on my TextBlock.Inlines in the UI. I couldn't find how to do this, is this possible?

Answer

Frank A. picture Frank A. · Mar 3, 2012

You could add a Dependency Property to a TextBlock Subclass

public class BindableTextBlock : TextBlock
{
    public ObservableCollection<Inline> InlineList
    {
        get { return (ObservableCollection<Inline>)GetValue(InlineListProperty); }
        set { SetValue(InlineListProperty, value); }
    }

    public static readonly DependencyProperty InlineListProperty =
        DependencyProperty.Register("InlineList",typeof(ObservableCollection<Inline>), typeof(BindableTextBlock), new UIPropertyMetadata(null, OnPropertyChanged));

    private static void OnPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
    {
        BindableTextBlock textBlock = sender as BindableTextBlock;
        ObservableCollection<Inline> list = e.NewValue as ObservableCollection<Inline>;
        list.CollectionChanged += new     System.Collections.Specialized.NotifyCollectionChangedEventHandler(textBlock.InlineCollectionChanged);
    }

    private void InlineCollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
    {
        if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add)
        {
            int idx = e.NewItems.Count -1;
            Inline inline = e.NewItems[idx] as Inline;
            this.Inlines.Add(inline);
        }
    }
}