Cancel Form Closing event : Form Event « GUI Windows Forms « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. GUI Windows Forms
3. Form Event

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

public class FormClosingEventCancle : System.Windows.Forms.Form
{
  private System.ComponentModel.Container components = null;

  public FormClosingEventCancle()
  {
    InitializeComponent();

    this.Closing += new System.ComponentModel.CancelEventHandler(this.FormClosingEventCancle_Closing);
  }

  protected override void Dispose( bool disposing )
  {
    if( disposing )
    {
      if (components != null) 
      {
        components.Dispose();
      }
    }
    base.Dispose( disposing );
  }

  private void InitializeComponent()
  {
    this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
    this.ClientSize = new System.Drawing.Size(280, 177);

  }
  [STAThread]
  static void Main() 
  {
    Application.Run(new FormClosingEventCancle());
  }

  private void FormClosingEventCancle_Closing(object sender, System.ComponentModel.CancelEventArgs e)
  {
    DialogResult dr = MessageBox.Show("Do you REALLY want to close this app?",
      "Closing event!", MessageBoxButtons.YesNo);
    if(dr == DialogResult.No)
      e.Cancel = true;
    else
      e.Cancel = false;    
  }
}

23.3.Form Event
	23.3.1.	Form size changed event handler
	23.3.2.	All form events
	23.3.3.	React to form resize event
	23.3.4.	Paint event
	23.3.5.	Paint two forms with one paint event handler
	23.3.6.	Paint one forms with two paint event handler
	23.3.7.	Form Mouse Up event
	23.3.8.	Form mouse move event
	23.3.9.	Form Key event
	23.3.10.	Form life time event: Closing, Load, Closed, Activated, Deactivate
	23.3.11.	Cancel Form Closing event
	23.3.12.	Form Paint event