Question

On Visual Studio C# Express 2010, I find cancelling .Validating by setting e.Cancel as per the docs causes the app to hang upon exit. e.g. run the below and click title bar ‘X’.

Anyone know a solution? Thanks.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void textBox1_Validating(object sender, CancelEventArgs e)
        {
            e.Cancel = true;
        }
    }
}

Answer 1

The form is prevented from being closed as textBox1 is not valid – if you still want to allow the user to close the form then you can handle the FormClosing event like this:

private void Form1_FormClosing(object sender, FormClosingEventArgs e)
{
    e.Cancel = false;
}

You need to wire up this event in the normal way, for example:

this.FormClosing += new FormClosingEventHandler(this.Form1_FormClosing);

If you debug the above event handler you will see that e.Cancel is true if your validation event hanlder set e.Cancel to be true.