Question

I have a radio button on my Windows Form. How can I determine if the CheckChanged event occurred due to a user clicking or selecting the radio button vs programatically setting the event with

this.radioButtonAdd.Checked = true; 

I would like some code to take a different action depending on if the user clicked the button or I raised the event myself.

Or maybe the better question is how do I handle the event when a user clicks vs when the state is changed in my code.

Answer 1

I think I found a pretty good answer.

All Windows Forms controls have a property called ‘Tag’. its value can be any object.

So if I want to ingore any programatic changes I can do the following:

radioButton.Tag = 'ignore' radioButton.Checked = true 

then in the event handler:

private void radioButton_CheckedChanged(object sender, EventArgs e) {     if (radioButton.Checked)     {         // Tag will be null in cases where the user clicks         if (this.radioButtonAdd.Tag == null)         {             // do something         }         else         {              // swallow action             // reset Tag             this.radioButtonAdd.Tag = null;         }     } }