Wpf datatrigger not updating
For example, if I make a change that doesn't make the vm invalid, the color is correctly Green.But if I then make a change to make the vm invalid, it stays green, when it should be Red.Obviously you only have to call Notify Property Changed in the setter's of the properties that you bind to - the rest can remain the way they are.The Observable Collection on the other hand is very easy to deal with - it simply requires you to use this specific list type in those situations where you want changes to the source list reflected in a binding destination.We then add a trigger, which listens to the Is Mouse Over property - once this property changes to True, we apply two setters: We change the Foreground to red and then we make it underlined.This is a great example on how easy it is to use triggers to apply design changes, completely without any code-behind code.So far in this tutorial, we have mostly created bindings between UI elements and existing classes, but in real life applications, you will obviously be binding to your own data objects.
This also opens up for binding your trigger to a property on a different control.However, using triggers, you can change the value of a given property, once a certain condition changes.Triggers come in multiple flavors: Property triggers, event triggers and data triggers.The problem is that none of the buttons seems to work. The first step is to get the UI to respond to changes in the list source (Items Source), like when we add or delete a user.
What we need is a list that notifies any destinations of changes to its content, and fortunately, WPF provides a type of list that will do just that.This is a bit more cumbersome than just changing the list type, like we did above, but it's still one of the simplest way to accomplish these automatic updates.