如何检测 MenuStrip 何时将其其中一个项目扩展为其子项目?

Question

我把这个MenuStrip左停靠在一个表单中，带有LayoutStyle = VerticalStackWithOverflow，我编写了这两个事件处理程序，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，但某些菜单项有自己的菜单项(作为选择树)，当用户将鼠标从根菜单条移动到选项时，菜单条收缩回其"仅图标"模式，因此展开的菜单看起来很笨拙。

有没有办法检测 MenuStrip 何时将其其中一个项目扩展为其子项目，以便我可以挂起正确的调整例程？

谢谢！

编辑

这是DonBoitnott移植到 VB.NET 的答案，我只在处理程序中添加了一个后续MenuDeactivate，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，以及添加MenuActivate和MenuDeactivate可以使其行为：

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;
}
}