我搜索并阅读了有关该主题的一些内容，但找不到一个可行的示例。所以我想我试着创造一个。它并不完美，但它是入门的基础。例如，我没有尝试具有附加子项的项目。
要呈现菜单项，您不必重写项目的OnPaint 方法。我们最好使用ToolStripProfessionalRenderer。渲染器将管理显示菜单项所需的一切。因此我们必须创建自己的类 MyToolStripProfessionalRenderer 并设置Toolstrip.Renderer 属性。
Public Class Form1
Public Sub New()
InitializeComponent()
MenuStrip1.Renderer = New MyToolStripProfessionalRenderer()
End Sub
End Class
在我们的类中，我们必须重写OnRenderItemText 方法。此方法绘制项目名称和快捷方式的字符串。基本方法很简单，用左对齐绘制名称，用右对齐绘制快捷方式。我们的自定义方法应该用左对齐绘制名称，用左对齐绘制快捷方式。因此，我们需要找到绘制快捷方式的合适位置。我创建了一个循环检查所有项目的快捷方式文本以找到具有最高宽度的项目。从中创建一个矩形并在此矩形中绘制字符串。
注意：使用此示例时，您必须在设计器中手动设置ShortcutKeyDisplayString 属性，否则它总是为空。
/主要修改：
我们还必须更改 autosize 算法以设置每个下拉菜单的 with。
新的自动宽度：图像宽度 + 一些空间 +
最大的 Itemtext + 一些空格 + 最大的 ShortCutText + 一些空格
因此我重写了Initialize(toolStrip As System.Windows.Forms.ToolStrip) 方法。
首先，我添加了一些常量来设置空格。为了计算宽度，我从所有项目中获取并找到子项目的最大文本，然后为项目设置新宽度。
注意：如果您的下拉菜单有另一个下拉菜单，那么您必须
添加递归。
Imports System.Windows.Forms
Public Class MyToolStripProfessionalRenderer
Inherits ToolStripProfessionalRenderer
Protected iconwidth As Integer = 22 ' the width of image icons
Protected paddingIconToText As Integer = 3
Protected paddingTextToShortCut As Integer = 20
Protected paddingShortCutToBoarder As Integer = 20
Private Enum TextType
Text = 0
Shortcut = 1
End Enum
Protected Overrides Sub OnRenderItemText(e As System.Windows.Forms.ToolStripItemTextRenderEventArgs)
' render only ToolStripMenuItems
If e.Item.IsOnDropDown And TypeOf e.Item Is ToolStripMenuItem Then
Dim MenuItem As ToolStripMenuItem = e.Item
Dim Name As String = MenuItem.Text
Dim Shortcut As String = MenuItem.ShortcutKeyDisplayString
'avoid double draw. The method is called twice for each item, check what should be drawn, Text or Shortcut?
Dim Mode As TextType
If e.Text = Name Then
Mode = TextType.Text
Else
Mode = TextType.Shortcut
End If
If Mode = TextType.Text Then
' this is our column for the menuitem text
Dim FirstColumn As Rectangle = New Rectangle(MenuItem.ContentRectangle.Left + iconwidth + paddingIconToText,
MenuItem.ContentRectangle.Top + 1,
MenuItem.Width - iconwidth - paddingIconToText,
MenuItem.Height)
' drawing the menu item
e.Graphics.DrawString(Name, MenuItem.Font, New SolidBrush(MenuItem.ForeColor), FirstColumn)
' this is the Shortcut to display, be sure to have set it manually
Else
' to align the text on the wanted position, we need to know the width for the shortcuts, this depends also on the other menu items
Dim CurStrip As ToolStrip = MenuItem.GetCurrentParent()
Dim fShortCutWidth As Single = 0
' lets find the other menuitems for this group
For Each item As Object In CurStrip.Items
' lets look for the ToolStripMenuItem only
If TypeOf item Is ToolStripMenuItem Then
Dim ChildItem As ToolStripMenuItem = item
Dim sCurShortcut As String = ChildItem.ShortcutKeyDisplayString
' how many pixels are needed to draw the current shortcut?
Dim size As SizeF = e.Graphics.MeasureString(sCurShortcut, ChildItem.Font)
If size.Width > fShortCutWidth Then
fShortCutWidth = size.Width ' save it for later
End If
End If
Next
' avoid to lose 1 pixel by casting to integer
Dim ShortCutWidth As Integer = Convert.ToInt32(fShortCutWidth) + 1
If fShortCutWidth > 0 Then
' this is our second column for the shortcut text
Dim SecondColumn As Rectangle = New Rectangle(MenuItem.Width - ShortCutWidth - paddingShortCutToBoarder,
MenuItem.ContentRectangle.Top + 1,
ShortCutWidth,
MenuItem.Height)
' drawing the shortcut
e.Graphics.DrawString(Shortcut, MenuItem.Font, New SolidBrush(MenuItem.ForeColor), SecondColumn)
End If
End If
Else ' there might be other items, use the default method
MyBase.OnRenderItemText(e)
End If
End Sub
Protected Overrides Sub Initialize(toolStrip As System.Windows.Forms.ToolStrip)
MyBase.Initialize(toolStrip)
' custom autosize algorithm
' 1: Find all dropdownbuttons
' 2: Get all Menuitems within dropdown
' 3: find the largest string of the dropdownitems text
' 4: find the latgest string of the dropdownitems shortcuttext
' 5: set the width for all items = picture width + padding + longest_itemtext + padding + longest_shortcuttext + padding
For Each item As ToolStripItem In toolStrip.Items ' get all dropdownbuttons
If TypeOf item Is ToolStripDropDownButton Then
Dim btn As ToolStripDropDownButton = item
If btn.HasDropDownItems Then ' dropdownitems
Dim MaxSizeOfItemName As Single = 0
Dim MaxSizeOfShortCutName As Single = 0
Dim CurSizeOfItemName As Single = 0
Dim CurSizeOfShortCutName As Single = 0
For Each child As ToolStripItem In btn.DropDownItems ' menu items within dropdown menu
' find the largest strings of dropdownitems
If TypeOf child Is ToolStripMenuItem Then
Dim CurrentMenuItem As ToolStripMenuItem = child
CurSizeOfItemName = TextRenderer.MeasureText(CurrentMenuItem.Text, child.Font).Width
CurSizeOfShortCutName = TextRenderer.MeasureText(CurrentMenuItem.ShortcutKeyDisplayString, child.Font).Width
MaxSizeOfItemName = Math.Max(MaxSizeOfItemName, CurSizeOfItemName)
MaxSizeOfShortCutName = Math.Max(MaxSizeOfShortCutName, CurSizeOfShortCutName)
End If
Next
If MaxSizeOfItemName > 0 Then
Dim autowidth As Integer = iconwidth + paddingIconToText + Convert.ToInt32(MaxSizeOfItemName) + 1 + paddingTextToShortCut + Convert.ToInt32(MaxSizeOfShortCutName) + 1 + paddingShortCutToBoarder
' it's not enough to set only the dropdownitems' width, also have to change the ToolStripDropDownMenu width
Dim menu As ToolStripDropDownMenu = btn.DropDownItems.Item(0).GetCurrentParent() ' maybe there is a better way to get the menuobject?!
menu.AutoSize = False
menu.Width = autowidth
For Each child As ToolStripItem In btn.DropDownItems
child.AutoSize = False
child.Width = autowidth
Next
End If ' MaxSizeOfItemName
' CAUTION: this works only for the first level of menuitems, if your dropdownmenu has another dropdownmenu, move the code above into a method and add recursion for each dropdownbutton with subitems
End If ' btn.HasDropDownItems
End If ' TypeOf item Is ToolStripDropDownButton
Next 'For Each item As ToolStripItem
End Sub
End Class