如何检测 MenuStrip 何时将其项目之一扩展为其子项目？

Question

我将此 MenuStrip 左停靠在一个表单中，使用 LayoutStyle = VerticalStackWithOverflow，我编写了这两个事件处理程序以使其项目仅在用户将鼠标移到 MenuStrip 上时才显示其文本：

Private Sub MenuStripMainMenu_MouseEnter(sender As Object, e As EventArgs) Handles MenuStripMainMenu.MouseEnter
    For Each c In MenuStripMainMenu.Items.OfType(Of ToolStripItem)
        c.DisplayStyle = ToolStripItemDisplayStyle.ImageAndText
    Next
End Sub

Private Sub MenuStripMainMenu_MouseLeave(sender As Object, e As EventArgs) Handles MenuStripMainMenu.MouseLeave, MenuStripMainMenu.LostFocus
    For Each c In MenuStripMainMenu.Items.OfType(Of ToolStripItem)
        c.DisplayStyle = ToolStripItemDisplayStyle.Image
    Next
End Sub

虽然这工作正常，但一些 MenuItems 有自己的 MenuItems（作为选择树），当用户将鼠标从根 MenuStrip 移动到选项时，MenuStrip 收缩回其 "icon-only"模式，所以展开的菜单看起来很笨拙。

有什么方法可以检测 MenuStrip 何时将其项目之一扩展为其子项目，以便我可以挂起适当的调整例程？

非常感谢！

编辑

这是移植到 VB.NET，我只在 MenuDeactivate 处理程序中添加了一个后续操作，以便在菜单停用后立即将条带缩小回仅图像：

Private MenuStripMainMenu_activated As Boolean = False

Private Sub MenuStripMainMenu_MenuActivate(sender As Object, e As EventArgs) Handles MenuStripMainMenu.MenuActivate
    MenuStripMainMenu_activated = True
End Sub

Private Sub MenuStripMainMenu_MenuDeactivate(sender As Object, e As EventArgs) Handles MenuStripMainMenu.MenuDeactivate
    MenuStripMainMenu_activated = False
    MenuStripMainMenu_MouseLeave(sender, e)
End Sub

Private Sub MenuStripMainMenu_MouseEnter(sender As Object, e As EventArgs) Handles MenuStripMainMenu.MouseEnter
    For Each c In MenuStripMainMenu.Items.OfType(Of ToolStripItem)
        c.DisplayStyle = ToolStripItemDisplayStyle.ImageAndText
    Next
End Sub

Private Sub MenuStripMainMenu_MouseLeave(sender As Object, e As EventArgs) Handles MenuStripMainMenu.MouseLeave
    If Not MenuStripMainMenu_activated Then
        For Each c In MenuStripMainMenu.Items.OfType(Of ToolStripItem)
            c.DisplayStyle = ToolStripItemDisplayStyle.Image
        Next
    End If
End Sub

Answer 1

您当前拥有的事件的组合，并添加 MenuActivate 和 MenuDeactivate 可以使行为：

 public partial class Form1 : Form
    {
        private Boolean _activated = false;

        public Form1()
        {
            InitializeComponent();
        }

        private void menuStrip1_MouseEnter(Object sender, EventArgs e)
        {
            foreach (var c in menuStrip1.Items.OfType<ToolStripItem>())
                c.DisplayStyle = ToolStripItemDisplayStyle.ImageAndText;
        }

        private void menuStrip1_MouseLeave(Object sender, EventArgs e)
        {
            if (!_activated)
            {
                foreach (var c in menuStrip1.Items.OfType<ToolStripItem>())
                    c.DisplayStyle = ToolStripItemDisplayStyle.Image;
            }
        }

        private void menuStrip1_MenuActivate(Object sender, EventArgs e)
        {
            _activated = true;
        }

        private void menuStrip1_MenuDeactivate(Object sender, EventArgs e)
        {
            _activated = false;
            foreach (var c in menuStrip1.Items.OfType<ToolStripItem>())
                c.DisplayStyle = ToolStripItemDisplayStyle.Image;
        }
    }

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