How to access DataContext class instance created in XAML in codebehind?

Question

MyData is a class simply storing a ColorName property.

In XAML I can create an instance for my XAML datacontext by

<c:MyData x:Key="myDataSource">

Now,

How do I access and change the ColorName stored in this instance of MyData (which was created in XAML with "myDataSource" key) in my code behind?

I hope the question is clear. I 'd like to change the color programmatically. How do I get hold of the MyData class instance ? Thank you

<DockPanel
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:c="clr-namespace:SDKSample">
  <DockPanel.Resources>
    <c:MyData x:Key="myDataSource"/>
  </DockPanel.Resources>
  <DockPanel.DataContext>
    <Binding Source="{StaticResource myDataSource}"/>
  </DockPanel.DataContext>
  <Button Background="{Binding Path=ColorName}"
          Width="150" Height="30">I am bound to be RED!</Button>
</DockPanel>

Please consider [my opinion](http://stackoverflow.com/a/16991850/643085) on this. — Federico Berasategui, Jul 05 '13 at 19:53
@HighCore certainly interesting +1d blindly---however given my current competency level, not in a position to comment either way :p Im sure I'll have an opinion 211 apples later — iAteABug_And_iLiked_it, Jul 05 '13 at 20:06

score 17 · Accepted Answer · answered Jul 05 '13 at 19:54

17

To access a resource from code-behind, give the DockPanel a name and then:

var resource = dockPanel.Resources["myDataSource"];

Alternatively, you can get its DataContext:

var dataContext = dockPanel.DataContext as MyData

answered Jul 05 '13 at 19:54

Arian Motamedi

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3

Your 'Alternative' is Superlative – Scott Solmer Aug 18 '16 at 14:31
I'm doing something similar: I say the following in the event handler of the button that is trying to read the text from textBox ```var dataContext = myWindow.DataContext as myClass;``` and then using it as ```System.Windows.MessageBox.Show(dataContext.Text);```, but ```dataContext``` stays null. What might be the problem? – miguello Jun 22 '22 at 18:31

How to access DataContext class instance created in XAML in codebehind?

1 Answers1

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