将自定义上下文菜单项添加到 Windows 窗体标题栏

Question

我在 MSDN 上找到了 a thread，它展示了如何将项目添加到 Windows 窗体标题栏的上下文菜单中。

不幸的是，它没有显示如何使用自定义菜单项注册事件，我一直无法弄清楚如何去做。下面是一个示例应用程序，可以将其复制并粘贴到新的 Windows 窗体应用程序中。如何完成示例？

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

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

            IntPtr hMenu = GetSystemMenu(Handle, false);
            if (hMenu != IntPtr.Zero)
            {
                var menuInfo = new MENUITEMINFO
                   {
                       cbSize = (uint) Marshal.SizeOf(typeof (MENUITEMINFO)),
                       cch = 255,
                       dwTypeData = "Test Item",
                       fMask = 0x1 | 0x2 | 0x10,
                       fState = 0,
                       fType = 0x0
                   };

                InsertMenuItem(hMenu, 0, true, ref menuInfo);
                DrawMenuBar(Handle);
            }
        }

        [DllImport("user32.dll")]
        static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
        [DllImport("user32.dll")]
        static extern bool DrawMenuBar(IntPtr hWnd);
        [DllImport("user32.dll")]
        static extern bool InsertMenuItem(IntPtr hMenu, uint uItem,
                          bool fByPosition, [In] ref MENUITEMINFO lpmii);


        [StructLayout(LayoutKind.Sequential)]
        public struct MENUITEMINFO
        {
            public uint cbSize;
            public uint fMask;
            public uint fType;
            public uint fState;
            public uint wID;
            public IntPtr hSubMenu;
            public IntPtr hbmpChecked;
            public IntPtr hbmpUnchecked;
            public IntPtr dwItemData;
            public string dwTypeData;
            public uint cch;
            public IntPtr hbmpItem;
        }
    }
}

Answer 1

您必须重写 WndProc 方法并截取新菜单的 id。

试试这个：

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

namespace WindowsFormsApplication11
{
  public partial class Form1 : Form
  {
    public const Int32 WM_SYSCOMMAND = 0x112;
    public const Int32 MF_BYPOSITION = 0x400;
    public const Int32 MYMENU1 = 1000;
    public const Int32 MUMENU2 = 1001;

    [DllImport("user32.dll")]
    private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
    [DllImport("user32.dll")]
    private static extern bool InsertMenu(IntPtr hMenu, Int32 wPosition, Int32 wFlags, Int32 wIDNewItem, string lpNewItem);

    public Form1()
    {
      InitializeComponent();
    }

    protected override void WndProc(ref Message msg)
    {
      if (msg.Msg == WM_SYSCOMMAND)
      {
        switch (msg.WParam.ToInt32())
        {
          case MYMENU1:
            MessageBox.Show("Hi from My Menu 1¡¡¡¡");
            return;
          case MUMENU2:
            MessageBox.Show("Hi from My Menu 2¡¡¡¡");
            return;
          default:
            break;
        }
      }
      base.WndProc(ref msg);
    }

    private void Form1_Load(object sender, EventArgs e)
    {
      IntPtr MenuHandle = GetSystemMenu(this.Handle, false);
      InsertMenu(MenuHandle, 5, MF_BYPOSITION, MYMENU1, "My Menu 1");
      InsertMenu(MenuHandle, 6, MF_BYPOSITION, MUMENU2, "My Menu 2");
    }
  }
}

Answer 2

对于分隔符，只需添加：

public const Int32 MF_SEPARATOR = 0x800;

在 Form_load 中：

InsertMenu(MenuHandle, 7, MF_BYPOSITION | MF_SEPARATOR, 0, string.Empty); // <-- Add a menu seperator

Answer 3

我继续，只是在示例代码中添加了必要的元素来注册 WndProc。这回答了注册 WndProc 的基本问题，而无需像以前的解决方案那样更改代码。 （它将添加的菜单保留在系统菜单的顶部）。

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

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

        IntPtr hMenu = GetSystemMenu(Handle, false);
        if (hMenu != IntPtr.Zero)
        {
            var menuInfo = new MENUITEMINFO
            {
                cbSize = (uint)Marshal.SizeOf(typeof(MENUITEMINFO)),
                cch = 255,
                dwTypeData = "Test Item",
                fMask = 0x1 | 0x2 | 0x10,
                fState = 0,
                // Add an ID for your Menu Item
                wID = 0x1,  
                fType = 0x0
            };

            InsertMenuItem(hMenu, 0, true, ref menuInfo);
            DrawMenuBar(Handle);
        }
    }

    [DllImport("user32.dll")]
    static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);
    [DllImport("user32.dll")]
    static extern bool DrawMenuBar(IntPtr hWnd);
    [DllImport("user32.dll")]
    static extern bool InsertMenuItem(IntPtr hMenu, uint uItem,
                      bool fByPosition, [In] ref MENUITEMINFO lpmii);


    [StructLayout(LayoutKind.Sequential)]
    public struct MENUITEMINFO
    {
        public uint cbSize;
        public uint fMask;
        public uint fType;
        public uint fState;
        public uint wID;
        public IntPtr hSubMenu;
        public IntPtr hbmpChecked;
        public IntPtr hbmpUnchecked;
        public IntPtr dwItemData;
        public string dwTypeData;
        public uint cch;
        public IntPtr hbmpItem;
    }

    // Add ID for the Menu
    private const int WM_SYSCOMMAND = 0x112; 
    // Event method for the Menu
    protected override void WndProc(ref Message m)
    {
        base.WndProc(ref m);
                                            //m.WParam = the wID you gave the Menu Item
        if ((m.Msg == WM_SYSCOMMAND) && ((int)m.WParam == 0x1))
        {
            MessageBox.Show("Test Item Dialog");
        }

    }
}

}