A read-only CheckBox in C# WPF

Question

I am having a tricky problem, I want some slightly unusual behaviour from a checkbox and can\'t seem to figure it out. Any suggestions would be most welcome. The behaviour I

Answer 1

I had a need for the AutoCheck functionality be off as well for a Checkbox/RadioButton, where I wanted to handle the Click event without having the control auto-check. I've tried various solutions here and on other threads and was unhappy with the results.

So I dug into what WPF is doing (using Reflection), and I noticed:

1. Both CheckBox & RadioButton inherit from the ToggleButton control primitive. Neither of them have a OnClick function.
2. The ToggleButton inherits from the ButtonBase control primitive.
3. The ToggleButton overrides the OnClick function and does: this.OnToggle(); base.OnClick();
4. ButtonBase.OnClick does 'base.RaiseEvent(new RoutedEventArgs(ButtonBase.ClickEvent, this));'

So basically, all I needed to do was override the OnClick event, don't call OnToggle, and do base.RaiseEvent

Here's the complete code (note that this can easily be reworked to do RadioButtons as well):

using System.Windows.Controls.Primitives;

public class AutoCheckBox : CheckBox
{

    private bool _autoCheck = false;
    public bool AutoCheck {
        get { return _autoCheck; }
        set { _autoCheck = value; }
    }

    protected override void OnClick()
    {
        if (_autoCheck) {
            base.OnClick();
        } else {
            base.RaiseEvent(new RoutedEventArgs(ButtonBase.ClickEvent, this));
        }
    }

}

I now have a CheckBox that doesn't auto-check, and still fires the Click event. Plus I can still subscribe to the Checked/Unchecked events and handle things there when I programmatically change the IsChecked property.

One final note: unlike other solutions that do something like IsChecked != IsChecked in a Click event, this won't cause the Checked/Unchecked/Indeterminate events to fire until you programmatically set the IsChecked property.