CODEWITHSUNDEEP
wpfbinding
Gerard
Gerard

Reputation: 13397

How can I overrule/change and then reset a Binding?

I have a Canvas whose Width & Height are databound, e.g. Width:
Width="{Binding DrawingSize.Width, NotifyOnTargetUpdated=True}".
When I set the Canvas's Width somewhere in code behind to another value, the Binding is lost.
Can somebody explain why that is or where MSDN explains it?

Upvotes: 0

Views: 32

Answers (1)

Julien Lebosquain
Julien Lebosquain

Reputation: 41233

MSDN explains this in the Dependency Property Value Precedence:

Dynamic resources and bindings have the precedence of where they were set, but the value is deferred. One consequence of this is that if you set a dynamic resource or binding to a local value, any change to the local value replaces the dynamic resource or binding entirely.

You can use SetCurrentValue to change the current value without overriding anything. However, even if there are valid usages for this method, I personally wouldn't recommend it. You're likely to run into other problems such as "who set this value, that's not the one I expected", or "the binding has changed too early, I lost my current value". Consider using the coercion mechanism, described in the same MSDN page, instead.

Upvotes: 1

Related Questions