Catching the close event on a c# form

Question

Hey! I am not trying to push my luck here but I have another c# question. I have tried every possible event I found using google. Here is the code:

 private void Form1_OnClose()
        {
            MessageBox.Show("I was closed -2");
        }

        private void Form1_Exit(object sender, EventArgs evArgs)
        {
            MessageBox.Show("I was closed -1");         
        }
        private void Form1_Closing(object sender, System.ComponentModel.CancelEventArgs e)
        {
            MessageBox.Show("I was closed 0");
        }     

        private void Form1_Closed(object sender, EventArgs e)
        {
            MessageBox.Show("I was closed 1");
        }
        private void Form1_FormClosed(Object sender, FormClosedEventArgs e)
        {

            MessageBox.Show("I was closed 2");
        }

Not one of these trigger anything when I either do Alt+f4 or click on the X button. What am I doing wrong here?

Answer 1

You might be missing actual subscription code, which is something along these lines:

this.Closing += Form1_Closing;

Instead, try overriding OnXXX methods - this is the preferred way of doing things.

Answer 2

Are these methods actually assigned as event handlers? Go to design mode, select the form, then click the little lightning bolt above the properties window. Then find the event you want (Closing probably) and double click it.

Answer 3

The error is likely that you aren't wiring the events at the right time. Check your program.cs file. It should look something like this:

using System;
using System.ComponentModel;
using System.Threading;
using System.Windows.Forms;
namespace Test
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            Form form = new Form2();
            form.Closing += form_Closing;
            Application.Run(form);
        }
        private static void form_Closing(object sender, CancelEventArgs e)
        {
            MessageBox.Show("Closing");
        }
    }
}

I just ran this and the event fired.