截获WndProc过程

为防止点击窗体右上角的关闭按钮（X按钮）关闭窗体，我们可以覆盖WndProc过程，只要发现消息为WM_SYSCOMMAND且wparam参数为SC_CLOSE就不让继续传下去。

Delphi代码：

unit Unit1;



interface



uses

  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,

  Vcl.Controls, Vcl.Forms, Vcl.Dialogs;



type

  TForm1 = class(TForm)

  private

    { Private declarations }

    procedure WndProc(var AMessage:TMessage);override;

  public

    { Public declarations }

  end;



var

  Form1: TForm1;



implementation



{$R *.dfm}



procedure TForm1.WndProc(var AMessage: TMessage);

begin

  if (AMessage.Msg=WM_SYSCOMMAND) and (AMessage.WParam=SC_CLOSE) then

    Exit

  else

    inherited;



end;



end.

C#代码：

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 WindowsFormsApplication7

{

    public partial class Form1 : Form

    {

        const int WM_SYSCOMMAND = 0x0112;

        const int SC_CLOSE = 0xF060;

        public Form1()

        {

            InitializeComponent();

        }

        protected override void WndProc(ref Message m)

        {

            if ((m.Msg == WM_SYSCOMMAND) && ((int)m.WParam == SC_CLOSE))

                return;

            base.WndProc(ref m);

        }

        private void Form1_Load(object sender, EventArgs e)

        {



        }

    }

}