Sergey

The behavior you describe is by design and it was implemented for performance reasons.
If you want to have the DataTemplate be re-evaluated, you can add a handler for property changes. In this handler, you add code that determines the new DataTemplate and sets it explicitly.

Bea

This scenario was never fixed in WPF, unfortunately.

However, you should be able to work around it with a converter, as you mention. This is how you can do it:

<Image Source=”{Binding ElementName=tb, Path=Text, Converter={StaticResource imageConverter}}” />

public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
FormatConvertedBitmap fcb = new FormatConvertedBitmap();
fcb.BeginInit();
fcb.Source = new BitmapImage(new Uri((string)value));
fcb.EndInit();
return fcb;
}

Let me know if this works for you.

Bea

Currently you can not bind to those properties, although they are DPs.

Notice that CroppedBitmap implements ISupportInitialize. In its implementation of this interface, it restricts the Source property to be set between calling BeginInit() and EndInit(). An exception is thrown if Source is not set between these calls, or if it’s set outside of these calls. This was done this way to improve our perf. Unfortunately, this a problem for data binding because we don’t have the value ready during this initialization.

It’s unlikely that this behavior will change for V1, but this scenario will not be forgotten when we discuss work for future versions of Avalon.

Thanks,
Bea

I have modified your examples to try to databind Source values and SourceRect values for a FormatConvertedBitmap
and a CroppedBitmap (below) in a datatemplate. However, when I do so I get exceptions about not being able to set the Source and SourceRect values. Is it possible to databind those properties?

FormatConvertedBitmap x:Name=”masterSource” Source=”{Binding Path=Filename}”
DestinationFormat=”gray4″

CroppedBitmap Source=”{Binding Path=Filename}” SourceRect=”{Binding Path=CropRext}”

Thanks,
Manny

I’ve replied to your post in the forums. Let me know if I got your scenario right.

Thanks,
Bea

I apologise if this is a little off-topic but you seem to be the most knowledgable person around with regards to data binding and a problem I am having is data binding-related.

I have posted a question on MSDN’s WPF forum to which I have had no reply. I find this a little worrying because what I want to do should be quite straightforward.

Would you be kind enough to look at my posting? If so it’s at,

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=247378&SiteID=1