Question

I want to set an image’s source according to its DataContext in a ChildWindow. Here is the XAML file:

<controls:ChildWindow x:Class="CEM.Controls.DialogWindow"
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
           xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls" Title="{Binding Title}">
  ...
  <Image x:Name="DialogIcon"></Image>
  ...
</controls:ChildWindow>

It’s working fine if I override the Show method of the ChildWindow and set the image’s source:

public new void Show()
{
    DialogIcon.Source = new BitmapImage(new Uri(@"/Images/DialogWindow/Confirm.png", UriKind.Relative));
    base.Show();
}

But it looks ugly and it’s not the “silverlight way”, so I decide to change:

<Image x:Name="DialogIcon" Source="{Binding DialogIconType, Converter={StaticResource DialogIconConverter}}"></Image>

You see I have a DialogIconConverter registered to bind the source from the DataContext.

public class DialogIconConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
       //currently it's an hard-coded path
       return new BitmapImage(new Uri(@"/Images/DialogWindow/Confirm.png", UriKind.Relative));
    }
    ...
 }

But it’s not working now, I have several other converters in this control which are working fine. Only this one is not working. Can you help to find where the problem is?

EDIT: DialogIconType is an enum, and also it’s a property of DialogContext. An instance of DialogContext will be assigned to DataContext property of the DialogWindow.

public enum DialogIconType
{ 
    Confirm,
    Alert,
    Error
}
public class DialogContext
{
    public string Title { get; set; }
    public string Content { get; set; }
    public DialogButtons Buttons { get; set; }
    public DialogIconType IconType { get; set; }
}
internal DialogWindow(DialogContext context)
{
    InitializeComponent();
    this.DataContext = context;
}

Answer 1

might be silly, but did you make sure that your converter is referenced properly in your xaml file ?

otherwise, I suggest trying this syntax as path for your URI (with images setup as resources):

return new BitmapImage(new Uri("pack://application:,,,/Images/DialogWindow/Confirm.png", UriKind.Relative));

EDIT :

ok, I think I’ve got it :
look into your output window, you will probably see some error 40 binding … blablabla…

My guess is that the converter is right, but the source of the binding isn’t, so basically the converter is not even used.

The reason is that your DialogIconType is not a dependency property, so it cannot be bound to.

in other words, this :

public DialogIconType IconType { get; set; }

should become this :

public static DependencyProperty IconTypeProperty = DependencyProperty.Register("IconType", typeof(DialogIconType), typeof(DialogContext));
public DialogIconType IconType
{
    get { return (DialogIconType)(GetValue(IconTypeProperty)); }
    set { SetValue(IconTypeProperty , value); }
}

plus, in your Xaml, you should Bind to “IconType”, and not “DialogIconType” (which is a type and not a property)

(this might even be the sole issue, as I’m not sure if a dependencyProperty Is actually realy needed here, now that I think of it)