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Answer 1

A:

The problem you're running into is that you're trying to use DataBinding where you shouldn't.

I disagree with other answers you've been getting in the link you've posted. While the ControlTemplate solutions appear neat and tidy, they don't get at the heart of your problem, which is, you're trying to use a single control (a CheckBox) to do two different things: show state (e.g. checked/unchecked) and perform logic (remote device, etc.).

ControlTemplates are designed to change the way a control appears, but not behaves. You're trying to change behavior, not appearance. See "What Is a ControlTemplate?" here for more details

To do that, you're going to have to store some forego the standard binding and handle some events:

XAML:

<Window x:Class="WPFCheckBoxClickTester.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <Grid>
     <CheckBox x:Name="foo" Checked="foo_Checked"></CheckBox>
    </Grid>
</Window>

Code-Behind:

using System.ComponentModel;
using System.Threading;
using System.Windows;

namespace WPFCheckBoxClickTester
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
     private BackgroundWorker _worker = new BackgroundWorker();

     public Window1()
     {
      InitializeComponent();

      foo.IsThreeState = false;
      this._worker.DoWork += new DoWorkEventHandler(_worker_DoWork);
      this._worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(_worker_RunWorkerCompleted);
     }

     private void _worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
     {
      foo.IsChecked = true;
      foo.IsEnabled = true;
      return;
     }

     private void _worker_DoWork(object sender, DoWorkEventArgs e)
     {
      Thread.Sleep(500);
      return;
     }

     private void foo_Checked(object sender, RoutedEventArgs e)
     {
      if( foo.IsChecked == true && this.foo.IsEnabled )
      {
       this.foo.IsChecked = false;
       this.foo.IsEnabled = false;

       this._worker.RunWorkerAsync();
      }
      return;
     }

    }
}

The above code example gives you the ability to execute some code async via BackgroundWorker -- I've put in a Thread.Sleep as a placeholder. I'm also using foo.IsEnabled as a sentinel value in foo_Checked, but you may need some extra state here to handle all of your cases (for instance, going from Checked to Unchecked).

micahtan 2009-06-08 23:13:58

Hi Micahtan,Thanks for your response, I'm sorry it has taken me so long to get back to you but I got moved onto an urgent project that needed finishing.Although your answer could definately work it does not feel that elegant to me as the checkbox checks itself and then when handling the checked event we set it back, if you watch the button when you click you can see the check appear and then disappear again.Ideally I want to be able to edit the template to disable the checking when the click occurs so it only happens when I set it, or the bound variable takes a new value.cheersed

EdWaugh 2009-07-06 18:14:06

Hi anyone on this thread, I solved my problem by creating a custom control based on button, see here:http://stackoverflow.com/questions/1088906/adding-a-custom-dependency-property-to-a-control-template-in-xamled

EdWaugh 2009-07-16 07:26:03

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