Wpf usercontrol dependency property not updating Neue leute kennenlernen augsburg
I don’t know the exact mechanism that enables this behavior, but we’re going to take advantage of it to make our binding work…
The control just changes background color when you set the enum to On (green), or Off (red). The problem is that the dependency property will take the enum member with number 0 as default, On Off. And when setting the value in XAML (or code for that matter) will not update the property backing the dependency property: The code to render this is found here: As you can see the left one is NOT green. On (value 0), and setting it (again) to On doesn’t trigger the execution of On Property Changed Callback.
I often get questions about WPF binding behaving differently than people expect in their usage case so here is post to help out with that.
When you bind to properties in WPF with for example: Value=”” the binding update behavior, i.e the trigger for value update, is controlled by the defaults set on the Dependency Property.
and I had prepared a long, off-topic rant about MVVM because of a bit of trouble I’m having with it at the moment. Maybe I’ll make it an on-topic post at some point in the future.
Since the Content of the both Content Presenters are string, “Hello” and “World” all other bindings on the Content Presenter are now resolved against these string values!However, in some cases the is not accessible: it happens for elements that are not part of the visual or logical tree.It can be very difficult then to bind a property on those elements…We can solve this (of course, otherwise what would be the point of writing this?😛 ) The first solution you might think about is setting the default value of the Dependency Property’s default value.
Well, if you used Content Presenters in your User Control, you would see this, instead: You would also see strange binding errors in the console System. Data Error: 40 : Binding Expression path error: 'Content Two Template' property not found on 'object' ''String' (Hash Code=-1506748533)'.