C# 禁止ALT+F4

1. Windows Forms中禁用表單的關閉按鈕

添加必要的命名空間：

using System.Runtime.InteropServices;

 

添加必要的常數和API函數的引用

private const int SC_CLOSE = 0xF060;

private const int MF_ENABLED = 0x00000000;

private const int MF_GRAYED = 0x00000001;

private const int MF_DISABLED = 0x00000002;

 

[DllImport("user32.dll", EntryPoint = "GetSystemMenu")]

private static extern IntPtr GetSystemMenu(IntPtr hWnd, int bRevert);

[DllImport("User32.dll")]

public static extern bool EnableMenuItem(IntPtr hMenu, int uIDEnableItem, int uEnable);

在表單的Load事件處理函數內添加代碼

private void Form6_Load(object sender, EventArgs e)

{
   IntPtr hMenu = GetSystemMenu(this.Handle, 0);
   EnableMenuItem(hMenu, SC_CLOSE, MF_DISABLED | MF_GRAYED);

}

 

2. Windows Forms中禁用表單的關閉按鈕和ALT+F4關閉

protected override CreateParams CreateParams

{
   get
   {
      const int CS_NOCLOSE = 0x200;
      CreateParams cp = base.CreateParams;
      cp.ClassStyle = cp.ClassStyle | CS_NOCLOSE;
      return cp;
   }

}

3.不允許拖動表單和最大化最小化按鈕
        protected override void WndProc(ref Message m)
        {
            base.WndProc(ref m);
            if (m.Msg == 0x84 && m.Result == (IntPtr)2) // 不讓拖動標題列
            {
                m.Result = (IntPtr)1;
            }
            if (m.Msg == 0xA3)                         // 雙擊標題列無反應
            {
                m.WParam = System.IntPtr.Zero;
            }
        }