CODEWITHSUNDEEP
c#wpfdata-binding
Vitalij
Vitalij

Reputation: 4625

In WPF how to get binding of a specific item from the code?

The example of this would be:

A textBox is bound to some data. There is a second text box which is not bind to anything. So I want to bind text box 2 to the same data 1st textBox is bound.

In other words I wan't to know if the DependencyObject stores some reference to it's data-bindings? If not, what is the way to find out all data-bindings of a specific object?

Upvotes: 27

Views: 44881

Answers (4)

Mark A. Donohoe
Mark A. Donohoe

Reputation: 30468

I know there's already an accepted answer, but is there some reason you're just not doing this?

<TextBox Name="textBox1" Text="{Binding Text1}"/>
<TextBox Name="textBox2" Text="{Binding Text, ElementName=textBox1}"/>

Now whatever textBox1 is bound to, even if that binding changes, textBox2 is as well, no code-behind needed.

Granted I'm basing this on the XAML as presented, and you very well may need the binding itself from code for something else, but if not, the above works just fine.

Upvotes: 3

Felipe Faria
Felipe Faria

Reputation: 604

You can get the binding of any dependency object using

System.Windows.Data.BindingOperations.GetBinding(DependencyObject target,DependencyProperty dp)

then set the binding with 

System.Windows.FrameworkElement.SetBinding(DependencyProperty dp, string path)

For example:

var binding = BindingOperations.GetBinding(textBox1,TextBox.TextProperty);
textBox2.SetBinding(TextBox.TextProperty, binding);

Upvotes: 17

Fredrik Hedblad
Fredrik Hedblad

Reputation: 84684

Try this

Xaml

<TextBox Name="textBox1" Text="{Binding Text1}"/>
<TextBox Name="textBox2" Text="No Binding"/>

Then we can set the binding of the TextProperty for textBox2 to the same as textBox1 with this code behind

BindingExpression bindingExpression = textBox1.GetBindingExpression(TextBox.TextProperty);
Binding parentBinding = bindingExpression.ParentBinding;
textBox2.SetBinding(TextBox.TextProperty, parentBinding);

Upvotes: 50

Peter van Kekem
Peter van Kekem

Reputation: 1447

You can do this in code by calling the SetBinding method.

Upvotes: -2

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