.net - Should I use WPF converter or trigger?

Question

I was wondering how do you decide when to use converters and when to use triggers. I prefer using a triggers for operations on GUI (like showing/hiding controls, changing their appearance etc.).

Some time ago I used a BooleanToVisibilityConverter for this purpose but now, I just don't need it, I do all things connected to the visibility using a triggers and I even started to think "what was the purpose of creating a BooleanToVisibilityConverter by the MS team?". Generally, when it's possible I try to use a declarative way to write the code - in this example - XAML.

What is your opinion of that?

Answer 1

I agree with you, I also try to use declarative code in XAML and prefer Triggers instead of Converters.

In most of the scenarios triggers can perform the same work as any converter but Converters can have custom/business logic as pchajer mentioned.

One limitation of Triggers is that Setters in your DataTriggers can only change properties of your UI elements; so, you can't update your ViewModels property with triggers, thats where Converters win, remember the ConvertBack method.

So, you can bind your VM property with a controls Visibility using BooleanToVisibilityConverter and even if your controls visibility is changed by some other means your VM property will get updated; generally it's not required that's why BooleanToVisibilityConverter gets replaced by triggers.

So in short -

Triggers can only perform OneWay operations whereas Converters can perform TwoWay operations