C# 右键单击菜单项时如何显示上下文菜单

How to show a Context Menu when you right click a Menu Item

提问by Rob Prouse

I am porting an MFC application to .NET WinForms. In the MFC application, you can right click on a menu or on a context menu item and we show another context menu with diagnostic and configuration items. I am trying to port this functionality to .NET, but I am having trouble.

我正在将 MFC 应用程序移植到 .NET WinForms。在 MFC 应用程序中，您可以右键单击菜单或上下文菜单项，我们会显示另一个带有诊断和配置项的上下文菜单。我正在尝试将此功能移植到 .NET，但遇到了问题。

I have been able to capture the right click, disable the click of the underlying menu and pop up a context menu at the right location, but the original menu disappears as soon as it loses focus.

我已经能够捕获右键单击，禁用底层菜单的单击并在正确的位置弹出上下文菜单，但是原始菜单一旦失去焦点就会消失。

In MFC, we show the new context menu by calling TrackPopupMenuExwith the TPM_RECURSEflag.

在 MFC 中，我们通过调用带有TPM_RECURSE标志的TrackPopupMenuEx 来显示新的上下文菜单。

ContextMenuand the newer ContextMenuStripclasses in .NET only have a Showmethod. Does anyone know how to do this in .NET?

.NET 中的ContextMenu和较新的ContextMenuStrip类只有一个Show方法。有谁知道如何在 .NET 中做到这一点？

EDIT

编辑

I have tried using TrackPopupMenuExthrough a p/invoke, but that limits you to using a ContextMenu instead of a ContextMenuStrip which looks out of place in our application. It also still does not work correctly. It doesn't work with the new MenuStripand ContextMenuStrip.

我曾尝试通过 ap/invoke使用TrackPopupMenuEx，但这限制了您只能使用 ContextMenu 而不是 ContextMenuStrip，这在我们的应用程序中显得格格不入。它也仍然无法正常工作。它不适用于新的MenuStrip和ContextMenuStrip。

I have also tried subclassing ToolStripMenuItem to see if I can add a context menu to it. That is working for MenuStrip, but ContextMenuStripstill allows the right click events to pass through as clicks.

我还尝试对 ToolStripMenuItem 进行子类化，以查看是否可以向其添加上下文菜单。这适用于MenuStrip，但ContextMenuStrip仍然允许右键单击事件作为点击通过。

采纳答案by Eren Aygunes

Edit, due to a comment:

编辑，由于评论：

In:

在：

protected override void OnClick(EventArgs e)
{
    if (SecondaryContextMenu == null || MouseButtons != MouseButtons.Right)
    {
        base.OnClick(e);
    }
}

this part

这部分

 MouseButtons != MouseButtons.Right

should and does compile as it is a call to Control.MouseButtons. Since the Form inherits Control class, it is sufficient to call MouseButtons property directly.

应该并且确实编译，因为它是对 Control.MouseButtons 的调用。由于 Form 继承了 Control 类，因此直接调用 MouseButtons 属性就足够了。

Hope this helps:

希望这可以帮助：

public partial class Form1 : Form
{
    class CustomToolStripMenuItem : ToolStripMenuItem
    {
        private ContextMenuStrip secondaryContextMenu;

        public ContextMenuStrip SecondaryContextMenu
        {
            get
            {
                return secondaryContextMenu;
            }
            set
            {
                secondaryContextMenu = value;
            }
        }

        public CustomToolStripMenuItem(string text)
            : base(text)
        { }

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

            base.Dispose(disposing);
        }

        protected override void OnClick(EventArgs e)
        {
            if (SecondaryContextMenu == null || MouseButtons != MouseButtons.Right)
            {
                base.OnClick(e);
            }
        }
    }

    class CustomContextMenuStrip : ContextMenuStrip
    {
        private bool secondaryContextMenuActive = false;
        private ContextMenuStrip lastShownSecondaryContextMenu = null;

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

        protected override void OnControlAdded(ControlEventArgs e)
        {
            e.Control.MouseClick += new MouseEventHandler(Control_MouseClick);
            base.OnControlAdded(e);
        }

        protected override void OnControlRemoved(ControlEventArgs e)
        {
            e.Control.MouseClick -= new MouseEventHandler(Control_MouseClick);
            base.OnControlRemoved(e);
        }

        private void Control_MouseClick(object sender, MouseEventArgs e)
        {
            ShowSecondaryContextMenu(e);
        }

        protected override void OnMouseClick(MouseEventArgs e)
        {
            ShowSecondaryContextMenu(e);
            base.OnMouseClick(e);
        }

        private bool ShowSecondaryContextMenu(MouseEventArgs e)
        {
            CustomToolStripMenuItem ctsm = this.GetItemAt(e.Location) as CustomToolStripMenuItem;

            if (ctsm == null || ctsm.SecondaryContextMenu == null || e.Button != MouseButtons.Right)
            {
                return false;
            }

            lastShownSecondaryContextMenu = ctsm.SecondaryContextMenu;
            secondaryContextMenuActive = true;
            ctsm.SecondaryContextMenu.Closed += new ToolStripDropDownClosedEventHandler(SecondaryContextMenu_Closed);
            ctsm.SecondaryContextMenu.Show(Cursor.Position);
            return true;
        }

        void SecondaryContextMenu_Closed(object sender, ToolStripDropDownClosedEventArgs e)
        {
            ((ContextMenuStrip)sender).Closed -= new ToolStripDropDownClosedEventHandler(SecondaryContextMenu_Closed);
            lastShownSecondaryContextMenu = null;
            secondaryContextMenuActive = false;
            Focus();
        }

        protected override void OnClosing(ToolStripDropDownClosingEventArgs e)
        {
            if (secondaryContextMenuActive)
            {
                e.Cancel = true;
            }

            base.OnClosing(e);
        }
    }

    public Form1()
    {
        InitializeComponent();


        CustomToolStripMenuItem itemPrimary1 = new CustomToolStripMenuItem("item primary 1");
        itemPrimary1.SecondaryContextMenu = new ContextMenuStrip();
        itemPrimary1.SecondaryContextMenu.Items.AddRange(new ToolStripMenuItem[] { 
            new ToolStripMenuItem("item primary 1.1"),
            new ToolStripMenuItem("item primary 1.2"),
        });

        CustomToolStripMenuItem itemPrimary2 = new CustomToolStripMenuItem("item primary 2");
        itemPrimary2.DropDownItems.Add("item primary 2, sub 1");
        itemPrimary2.DropDownItems.Add("item primary 2, sub 2");
        itemPrimary2.SecondaryContextMenu = new ContextMenuStrip();
        itemPrimary2.SecondaryContextMenu.Items.AddRange(new ToolStripMenuItem[] { 
            new ToolStripMenuItem("item primary 2.1"),
            new ToolStripMenuItem("item primary 2.2"),
        });

        CustomContextMenuStrip primaryContextMenu = new CustomContextMenuStrip();
        primaryContextMenu.Items.AddRange(new ToolStripItem[]{
            itemPrimary1,
            itemPrimary2
        });

        this.ContextMenuStrip = primaryContextMenu;
    }
}

回答by Jason Diller

You'll probably have to p/invoke the method.

您可能必须调用/调用该方法。

[DllImport("user32.dll")]
static extern bool TrackPopupMenuEx(IntPtr hmenu, uint fuFlags, int x, int y,
IntPtr hwnd, IntPtr lptpm);

const int TPM_RECURSE = 0x0001; 

回答by Eren Aygunes

This shows how to use multiple ContextMenus as well as different ones with any combination of mouse clicks.

这显示了如何使用多个 ContextMenu 以及通过任意鼠标单击组合使用不同的 ContextMenu。

More here: http://code.msdn.microsoft.com/TheNotifyIconExample

更多信息：http: //code.msdn.microsoft.com/TheNotifyIconExample