WPF XAML绑定

Question

Hello I have a problem with a binding that I want to do and can't find any information on how to do it. Basically I want to bind an object to a property of another object. For example

<TextBox Text="test" Tag="{Binding ElementName=TxtBx2}" x:Name="TxtBx1"/>
<TextBox Text="test" x:Name="TxtBx2"/>

This is kind of weird but it would help on the code that i'm implementing, so on a property of one object I want to have another object bind in xaml.

I don't know if this is possible, any pointers would be helpful Thanks, Ruben

Answer 1

That is how you do it; you just need to specify the Path .

<TextBox Text="test" Tag="{Binding ElementName=TxtBx2, Path=Text}" x:Name="TxtBx1"/>
<TextBox Text="test" x:Name="TxtBx2"/>

If you are wanting the DataContext of the TextBox ; then your Path would change accordingly.

<TextBox Text="test" Tag="{Binding ElementName=TxtBx2, Path=DataContext}" x:Name="TxtBx1"/>
<TextBox Text="test" x:Name="TxtBx2"/>

If you are needing to use the Tag property within a WPF application you might want to re-evaluate your approach as I have yet to use the Tag property since moving from WinForms as that need has been replaced by leveraging the data binding functionality within WPF.

UPDATE:

If your goal is to bind to a given control versus a property on the control; then don't specify the property name within the Path .

Based on your goal; attached behaviors would be a better approach and allow you to wrap the functionality within the extended DataGrid .

Answer 2

<TextBox Text="test" Tag="{Binding ElementName=TxtBx2,Path=Text}" x:Name="TxtBx1"/>
<TextBox Text="test" x:Name="TxtBx2"/>

Answer 3

Assuming you want the value of the Text property of TxtBx1 to be the value of the Text property in TxtBx2, you would use:

<TextBox x:Name="TxtBx1" Text="{Binding ElementName=TxtBx2, Path=Text}" />
<TextBox x:Name="TxtBx2" Text="test" />

Update

Assuming (possibly incorrectly again!) that you want to bind the TxtBx1 element to the Tag of TxtBx2, you would use:

<TextBox x:Name="TxtBx1" Text="test" />
<TextBox x:Name="TxtBx2" Tag="{Binding ElementName=TxtBx1}" Text="test" />

Just out of interest, why do you want to do such a thing?

Update 2

Assuming that you have a Datagrid that you've extended from the wpftoolkit datagrid and a user control that is a pager for that Datagrid, and when you move to another page you need to do some processing on the datagrid, then why don't you just either update the datagrid in your page change event (if using code behind), or update the items that the datagrid is bound to in your page change verb on your view model (if using MVVM)?

Answer 4

Well, it does make sense to bind to an entire object(not to any specific property) with items control such as this:

<ListBox x:Name="pictureBox" 
ItemsSource=”{Binding Source={StaticResource photos}}" …> 
......
</ListBox>