XAML Multi-Level Binding Source/Path Issue

Question

So I have this issue I've been trying various ways to tackle all day and nothing's catching and working for it. Basically I have a XAML object called ChromeWindow (derived from Window) which has in it's code-behind a DependencyProperty called AppChrome which stores a reference to an associated ApplicationChrome XAML object (derived from UserControl). ApplicationChrome's XAML file has a few x:Name'd objects (a TextBlock and Border for instance) to which I want to bind to from the ChromeWindow's XAML. The root of the ChromeWindow is x:Name'd as 'rootWindow' in the XAML, so I figured one of these bindings would work:

{Binding ElementName=rootWindow, Path=AppChrome.CaptionTextBlock.Text, Mode=OneWay}

But that complains of a BindingExpression path error such that the property 'CaptionTextBlock' (an x:Name'd TextBlock in AppChrome's XAML) cannot be found on object of type ApplicationChrome

So I tried this binding intead:

{Binding Source=AppChrome.CaptionTextBlock, Path=Text, Mode=OneWay}

And still no luck, this time complaints of a BindingExpression path error again, but this time that it cannot find the 'CaptionTextBlock' property on object of type String

I know I'm missing something really simple here, please help! ;D

Answer 1

Even though you have named those elements, they will not be available for binding unless there are dependency properties exposed for them.

ApplicationChrome would need to expose a dependency property called CaptionTextBlock for this binding to work.

Perhaps you could explain why you are trying to bind to these objects, so we could better understand your scenario. There is probably a better way of doing it, because this kind of binding is not only messy but rather unusual.