How do I stop binding properties from updating?

Question

I have a dialog that pops up over the main screen (it's actually a user control that appears on the page as per the application demo from Billy Hollis) in my application that has data from the main screen to be edited. The main screen is read only.

The problem I have is that when I change the data in the dialog, the data on the main screen updates as well. Clearly they are bound to the same object, but is there a way to stop the binding update until I click save in my dialog?

Answer 1

You could use a BindingGroup :

...
<StackPanel Name="panel">
    <StackPanel.BindingGroup>
        <BindingGroup Name="bindingGroup"/>
    </StackPanel.BindingGroup>
    <TextBox Text="{Binding Foo}"/>
    <TextBox Text="{Binding Bar}"/>
    <Button Name="btnSubmit" Content="Submit" OnClick="btnSubmit_Click"/>
    <Button Name="btnCancel" Content="Cancel" OnClick="btnCancel_Click"/>
</StackPanel>
...

Code behind :

private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
    panel.BindingGroup.BeginEdit();
}

private void btnSubmit_Click(object sender, RoutedEventArgs e)
{
    panel.BindingGroup.CommitEdit();
    panel.BindingGroup.BeginEdit();
}

private void btnCancel_Click(object sender, RoutedEventArgs e)
{
    panel.BindingGroup.CancelEdit();
    panel.BindingGroup.BeginEdit();
}

Answer 2

They only way I've seen it done is how Josh Smith mentions here with converters. Not the easiest method though.

Answer 3

Have a look at the Binding.UpdateSourceTrigger property.

You can set the Binding in your dialog like so

<TextBox Name="myTextBox" 
    Text={Binding Path=MyProperty, UpdateSourceTrigger=Explicit} />

And then call the UpdateSource method in your button save event

myTextBox.GetBindingExpression(TextBox.TextProperty).UpdateSource();

Once you've called UpdateSource the source object will be updated with the value from the TextBox