Cancel uncheck in WPF

Question

I use checkbox in WPF window. I use some logic in unchecked event of checkbox. And I want to cancel uncheck if need it in the body of this event. How can I do this?

    private void chApprove_Checked(object sender, RoutedEventArgs e)
    {
        btnAddDepartment.IsEnabled = true;
        brnRemoveDepartment.IsEnabled = true;
    }

    private void chApprove_Unchecked(object sender, RoutedEventArgs e)
    {
        if (lbSource.Count == 0)
        {
            btnAddDepartment.IsEnabled = false;
            brnRemoveDepartment.IsEnabled = false;
        }
        else
        {
            MessageBox.Show("Staff already in use! Release it first from dependecies!");
            CheckBox myCheckBox = e.Source as CheckBox;
            myCheckBox.IsChecked = true;


        }
    }

Impossible to cancel uncheck !!!

Answer 1

void CheckBox1_Unchecked(object sender, RoutedEventArgs e)
{
    if(ResultOfSomeLogic)
    {    
        CheckBox myCheckBox = e.Source as CheckBox;
        myCheckBox.IsChecked = True; // Check it again
    }
    else
    {
    }
}

Also take a look at EventToCommand Binding Behaviour in MVVM Light to take advantage of CanExecute method.

Answer 2

You could do this easily with an attached behavior (rather than using code behind), you can take a look at this answer if you need a sample of how to structure one (it's only a few lines of code).

My spider-sense is telling me this isn't a very good idea though - I can't imagine a way to "justify" rechecking a checkbox that a user has clicked, it just strikes me as very jarring. Can you not either bind the enabled state of the checkbox to a property on your ViewModel or, if you have an ICommand bound to it, use the CanExecute delegate to enable/disable it based on the same logic?

Answer 3

Bind the IsChecked property of check box. Like

IsChecked="{Binding IsChecked, Mode = TwoWay}"

and in your class define some thing like dis;

private bool isChecked;

public bool IsChecked
{
  get
   {
     return this.isChecked;
   }

  set
  {
    this.isChecked = value;
    OnPropertyChanged["IsChecked"];
  }

}

and in your event

void CheckBox1_Unchecked(object sender, RoutedEventArgs e)
{
    if(ResultOfSomeLogic)
    {    
        this.IsChecked = true;
    }
    else
    {
    }
}

hope this will work for u..

Good Luck..