CODEWITHSUNDEEP
c#wpfupdatesourcetrigger
Kilazur
Kilazur

Reputation: 3187

Multiple UpdateSourceTriggers for one control

Simple problem, let's say I have this TextBox (which, as a matter of fact, I do have):

<TextBox.Text>
    <Binding  Path="MySourceProperty"
              Mode="OneWayToSource"
              UpdateSourceTrigger="PropertyChanged" />
</TextBox.Text>

It will succesfully update MySourceProperty whenever its Text property changes. What I want in addition to that is to MySourceProperty to get updated also when TextBox get focused.

Is there a way to have two UpdateSourceTriggers for one control?

For the details, I have a parent view containing a Label, bound to MySourceProperty, and another view, which contains a TextBox and a ComboBox.

So MySourceProperty should be updated when any of these events occur:

The last two events are obviously here because giving focus to a control doesn't change its Text or SelectedItem property, thus doesn't update MySourceProperty either.

EDIT: I've put the question in bold to be clear about what I want. I could solve the issue by using event handlers in code behind, but I'm trying hard to lose my WinForms habits. But if it is the only solution, feel free to answer with it.

Upvotes: 2

Views: 1708

Answers (3)

Sai
Sai

Reputation: 1394

Not sure if this helps you Kilazur

I would give a try first as Erno mentioned, if that won't fit your scenario then I have done something similar to this.

  1. Set the UpdateSourceTrigger to Explicit.

TextBox Name="itemNameTextBox" Text="{Binding Path=ItemName, UpdateSourceTrigger=Explicit}"

  1. Then call the UpdateSource in respective events in code behind (which you mentioned above).

    // itemNameTextBox is an instance of a TextBox
BindingExpression be = itemNameTextBox.GetBindingExpression(TextBox.TextProperty);
be.UpdateSource();

Referred from here

Upvotes: 2

Bolu
Bolu

Reputation: 8786

Is there a way to have two UpdateSourceTriggers for one control?`

The answer to your question is no. And even if it dose, the other Trigger is LostFocus.

If you are really like you said:

I could solve the issue by using event handlers in code behind, but I'm trying hard to lose my WinForms habits.

Then based on my understanding: you are using two control TextBox and ComboBox to update a single property MySourceProperty. My suggestion is that you should use TwoWay binding, or you can actually combine them by using ComboBox with ComboBox.IsEditable set to true, and data bind ComboBox.Text and ComboBox.SelectedItem with your MySourceProperty.

Edit: If you do need to do it the way you are doing, then instead of using just one property, the better way of doing it is to bind TextBox.Text and ComboBox.SelectedItem to two different properties. Then your MySourceProperty should return either of them based on their focus status.

Upvotes: 0

Emond
Emond

Reputation: 50712

You might want to put these controls that represent an entity in a single data template or user control. Then bind the datacontext of that control to the selected item of the combo box. The binding will now be relative to the selected item and will update automatically. No need to handle focus or multiple update triggers.

Upvotes: 0

Related Questions