ToolStripItem Class

Represents the abstract base class that manages events and layout for all the elements that a ToolStrip or ToolStripDropDown can contain.

Namespace: System.Windows.Forms
Assembly: System.Windows.Forms (in system.windows.forms.dll)

'Declaration
Public MustInherit Class ToolStripItem
	Inherits Component
	Implements IDropTarget, IComponent, IDisposable
'Usage
Dim instance As ToolStripItem

public abstract class ToolStripItem extends Component implements IDropTarget, IComponent, 
	IDisposable
public abstract class ToolStripItem extends Component implements IDropTarget, IComponent, 
	IDisposable
Not applicable.

A ToolStripItem is an element such as a button, combo box, text box, or label that can be contained in a ToolStrip control or a ToolStripDropDown control, which is similar to a Windows shortcut menu. The ToolStrip class manages the painting and keyboard and mouse input, including drag-and-drop input, for these elements, and the ToolStripItem class manages events and layout within the elements themselves.

ToolStripItem classes either inherit directly from ToolStripItem, or they inherit indirectly from ToolStripItem through ToolStripControlHost or ToolStripDropDownItem.

ToolStripItem controls must be contained in a ToolStrip, MenuStrip, StatusStrip, or ContextMenuStrip and cannot be added directly to a form. The various container classes are designed to contain an appropriate subset of ToolStripItem controls.

Note   A given ToolStripItem cannot have more than one parent ToolStrip. You must copy of the ToolStripItem and add it to other ToolStrip controls.

The following table shows the elements that derive from the ToolStripItem class and which therefore can be hosted in a ToolStrip or ToolStripDropDown.

Element

Description

ToolStripButton

A toolbar button that supports images and text.

ToolStripLabel

A text label typically used in a status bar or ToolStrip as a comment or title.

ToolStripSeparator

A non-selectable space or space with a vertical bar that visually groups elements.

ToolStripControlHost

A ToolStripItem that hosts a ToolStripComboBox, ToolStripTextBox, ToolStripProgressBar, other Windows Forms controls, or custom controls.

A ToolStripComboBox is a text box in which the user can enter text, along with a list from which the user can select text to fill the text box.

A ToolStripTextBox enables the user to enter text.

A ToolStripProgressBar represents a Windows progress bar control contained in a StatusStrip.

ToolStripDropDownItem

A ToolStripItem that hosts a ToolStripMenuItem, ToolStripSplitButton, and ToolStripDropDownButton.

A ToolStripMenuItem is a selectable option displayed on a menu or context menu.

A ToolStripSplitButton is a combination of a regular button and a drop-down button.

A ToolStripDropDownButton is a button that supports drop-down functionality.

ToolStripStatusLabel

A panel in a StatusStrip control.

The following code example demonstrates how to implement a custom ToolStripItem control.

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.Windows.Forms

' This class implements a ToolStripItem that highlights
' its border and text when the mouse enters enters its
' client rectangle. It has a clickable state which is
' exposed through the Clicked property and displayed
' by highlighting or graying out the item's image. 
Public Class RolloverItem
    Inherits ToolStripItem

   Private clickedValue As Boolean = False
   Private rolloverValue As Boolean = False
   
   Private imageRect As Rectangle
   Private textRect As Rectangle
   
   ' For brevity, this implementation limits the possible 
   ' TextDirection values to ToolStripTextDirection.Horizontal. 
   Public Overrides Property TextDirection() As ToolStripTextDirection
      Get
         Return MyBase.TextDirection
      End Get
      Set
         If value = ToolStripTextDirection.Horizontal Then
            MyBase.TextDirection = value
         Else
                Throw New ArgumentException( _
                "RolloverItem supports only horizontal text.")
         End If
      End Set
   End Property
   
   ' For brevity, this implementation limits the possible 
   ' TextImageRelation values to ImageBeforeText and TextBeforeImage. 
   Public Shadows Property TextImageRelation() As TextImageRelation
      Get
         Return MyBase.TextImageRelation
      End Get
      
      Set
            If Value = TextImageRelation.ImageBeforeText OrElse _
               Value = TextImageRelation.TextBeforeImage Then
                MyBase.TextImageRelation = Value
            Else
                Throw New ArgumentException("Unsupported TextImageRelation value.")
            End If
      End Set
   End Property
   
   ' This property returns true if the mouse is 
   ' inside the client rectangle.
   Public ReadOnly Property Rollover() As Boolean
      Get
         Return Me.rolloverValue
      End Get
    End Property

   ' This property returns true if the item 
   ' has been toggled into the clicked state.
   ' Clicking again toggles it to the 
   ' unclicked state.
   Public ReadOnly Property Clicked() As Boolean
      Get
         Return Me.clickedValue
      End Get
   End Property
   
   ' The method defines the behavior of the Click event.
   ' It simply toggles the state of the clickedValue field.
   Protected Overrides Sub OnClick(e As EventArgs)
      MyBase.OnClick(e)
      
      Me.clickedValue ^= True
    End Sub

   ' The method defines the behavior of the DoubleClick 
   ' event. It shows a MessageBox with the item's text.
   Protected Overrides Sub OnDoubleClick(e As EventArgs)
      MyBase.OnDoubleClick(e)
      
      Dim msg As String = String.Format("Item: {0}", Me.Text)
      
      MessageBox.Show(msg)
    End Sub

   ' This method defines the behavior of the MouseEnter event.
   ' It sets the state of the rolloverValue field to true and
   ' tells the control to repaint.
   Protected Overrides Sub OnMouseEnter(e As EventArgs)
      MyBase.OnMouseEnter(e)
      
      Me.rolloverValue = True
      
      Me.Invalidate()
    End Sub
   
   ' This method defines the behavior of the MouseLeave event.
   ' It sets the state of the rolloverValue field to false and
   ' tells the control to repaint.
   Protected Overrides Sub OnMouseLeave(e As EventArgs)
      MyBase.OnMouseLeave(e)
      
      Me.rolloverValue = False
      
      Me.Invalidate()
    End Sub
   
   ' This method defines the painting behavior of the control.
   ' It performs the following operations:
   '
   ' Computes the layout of the item's image and text.
   ' Draws the item's background image.
   ' Draws the item's image.
   ' Draws the item's text.
   '
   ' Drawing operations are implemented in the 
   ' RolloverItemRenderer class.
   Protected Overrides Sub OnPaint(e As PaintEventArgs)
      MyBase.OnPaint(e)
      
      If (Me.Owner IsNot Nothing) Then
         ' Find the dimensions of the image and the text 
         ' areas of the item. 
         Me.ComputeImageAndTextLayout()
         
         ' Draw the background. This includes drawing a highlighted 
         ' border when the mouse is in the client area.
         Dim ea As New ToolStripItemRenderEventArgs(e.Graphics, Me)
         Me.Owner.Renderer.DrawItemBackground(ea)
         
         ' Draw the item's image. 
         Dim irea As New ToolStripItemImageRenderEventArgs(e.Graphics, Me, imageRect)
         Me.Owner.Renderer.DrawItemImage(irea)
         
         ' If the item is on a drop-down, give its
         ' text a different highlighted color.
         Dim highlightColor As Color = IIf(Me.IsOnDropDown, Color.Salmon, SystemColors.ControlLightLight)
         
         ' Draw the text, and highlight it if the 
         ' the rollover state is true.
         Dim rea As New ToolStripItemTextRenderEventArgs(e.Graphics, Me, MyBase.Text, textRect, IIf(Me.rolloverValue, highlightColor, MyBase.ForeColor), MyBase.Font, MyBase.TextAlign)
         Me.Owner.Renderer.DrawItemText(rea)
      End If
    End Sub

   ' This utility method computes the layout of the 
   ' RolloverItem control's image area and the text area.
   ' For brevity, only the following settings are 
   ' supported:
   '
   ' ToolStripTextDirection.Horizontal
   ' TextImageRelation.ImageBeforeText 
   ' TextImageRelation.ImageBeforeText
   ' 
   ' It would not be difficult to support vertical text
   ' directions and other image/text relationships.
   Private Sub ComputeImageAndTextLayout()
      Dim cr As Rectangle = MyBase.ContentRectangle
      Dim img As Image = MyBase.Owner.ImageList.Images(MyBase.ImageKey)
      
      ' Compute the center of the item's ContentRectangle.
      Dim centerY As Integer = (cr.Height - img.Height) / 2
      
      ' Find the dimensions of the image and the text 
      ' areas of the item. The text occupies the space 
      ' not filled by the image. 
        If MyBase.TextImageRelation = _
        TextImageRelation.ImageBeforeText AndAlso _
        MyBase.TextDirection = ToolStripTextDirection.Horizontal Then

            imageRect = New Rectangle( _
            MyBase.ContentRectangle.Left, _
            centerY, _
            MyBase.Image.Width, _
            MyBase.Image.Height)

            textRect = New Rectangle( _
            imageRect.Width, _
            MyBase.ContentRectangle.Top, _
            MyBase.ContentRectangle.Width - imageRect.Width, _
            MyBase.ContentRectangle.Height)

        ElseIf MyBase.TextImageRelation = _
        TextImageRelation.TextBeforeImage AndAlso _
        MyBase.TextDirection = ToolStripTextDirection.Horizontal Then

            imageRect = New Rectangle( _
            MyBase.ContentRectangle.Right - MyBase.Image.Width, _
            centerY, _
            MyBase.Image.Width, _
            MyBase.Image.Height)

            textRect = New Rectangle( _
            MyBase.ContentRectangle.Left, _
            MyBase.ContentRectangle.Top, _
            imageRect.X, _
            MyBase.ContentRectangle.Bottom)

        End If
    End Sub
End Class

' This is the custom renderer for the RolloverItem control.
' It draws a border around the item when the mouse is
' in the item's client area. It also draws the item's image
' in an inactive state (grayed out) until the user clicks
' the item to toggle its "clicked" state.
Friend Class RolloverItemRenderer
    Inherits ToolStripSystemRenderer

    Protected Overrides Sub OnRenderItemImage(ByVal e As ToolStripItemImageRenderEventArgs)
        MyBase.OnRenderItemImage(e)

        Dim item As RolloverItem = e.Item 

        ' If the ToolSTripItem is of type RolloverItem, 
        ' perform custom rendering for the image.
        If (item IsNot Nothing) Then
            If item.Clicked Then
                ' The item is in the clicked state, so 
                ' draw the image as usual.
                e.Graphics.DrawImage(e.Image, e.ImageRectangle.X, e.ImageRectangle.Y)
            Else
                ' In the unclicked state, gray out the image.
                ControlPaint.DrawImageDisabled(e.Graphics, e.Image, e.ImageRectangle.X, e.ImageRectangle.Y, item.BackColor)
            End If
        End If
    End Sub

    ' This method defines the behavior for rendering the
    ' background of a ToolStripItem. If the item is a
    ' RolloverItem, it paints the item's BackgroundImage 
    ' centered in the client area. If the mouse is in the 
    ' item's client area, a border is drawn around it.
    ' If the item is on a drop-down or if it is on the
    ' overflow, a gradient is painted in the background.
    Protected Overrides Sub OnRenderItemBackground(ByVal e As ToolStripItemRenderEventArgs)
        MyBase.OnRenderItemBackground(e)

        Dim item As RolloverItem = e.Item 

        ' If the ToolSTripItem is of type RolloverItem, 
        ' perform custom rendering for the background.
        If (item IsNot Nothing) Then
            If item.Placement = ToolStripItemPlacement.Overflow OrElse item.IsOnDropDown Then
                Dim b As New LinearGradientBrush(item.ContentRectangle, Color.Salmon, Color.DarkRed, 0.0F, False)
                Try
                    e.Graphics.FillRectangle(b, item.ContentRectangle)
                Finally
                    b.Dispose()
                End Try
            End If

            ' The RolloverItem control only supports 
            ' the ImageLayout.Center setting for the
            ' BackgroundImage property.
            If item.BackgroundImageLayout = ImageLayout.Center Then
                ' Get references to the item's ContentRectangle
                ' and BackgroundImage, for convenience.
                Dim cr As Rectangle = item.ContentRectangle
                Dim bgi As Image = item.BackgroundImage

                ' Compute the center of the item's ContentRectangle.
                Dim centerX As Integer = (cr.Width - bgi.Width) / 2
                Dim centerY As Integer = (cr.Height - bgi.Height) / 2

                ' If the item is selected, draw the background
                ' image as usual. Otherwise, draw it as disabled.
                If item.Selected Then
                    e.Graphics.DrawImage(bgi, centerX, centerY)
                Else
                    ControlPaint.DrawImageDisabled(e.Graphics, bgi, centerX, centerY, item.BackColor)
                End If
            End If

            ' If the item is in the rollover state, 
            ' draw a border around it.
            If item.Rollover Then
                ControlPaint.DrawFocusRectangle(e.Graphics, item.ContentRectangle)
            End If
        End If
    End Sub

End Class

' This form tests various features of the RolloverItem
' control. RolloverItem conrols are created and added
' to the form's ToolStrip. They are also created and 
' added to a button's ContextMenuStrip. The behavior
' of the RolloverItem control differs depending on 
' the type of parent control.

Public Class RolloverItemTestForm
   Inherits Form
   Private toolStrip1 As System.Windows.Forms.ToolStrip
   Private WithEvents button1 As System.Windows.Forms.Button
   
   Private infoIconKey As String = "Information icon"
   Private handIconKey As String = "Hand icon"
   Private exclIconKey As String = "Exclamation icon"
   Private questionIconKey As String = "Question icon"
   Private warningIconKey As String = "Warning icon "
   
   Private components As System.ComponentModel.IContainer = Nothing
   
   
   Public Sub New()
      InitializeComponent()
      
      ' Set up the form's ToolStrip control.
      InitializeToolStrip()
      
      ' Set up the ContextMenuStrip for the button.
      InitializeContextMenu()
    End Sub
   
   
   ' This utility method initializes the ToolStrip control's 
   ' image list. For convenience, icons from the SystemIcons 
   ' class are used for this demonstration, but any images
   ' could be used.
   Private Sub InitializeImageList(ts As ToolStrip)
      If ts.ImageList Is Nothing Then
         ts.ImageList = New ImageList()
         ts.ImageList.ImageSize = SystemIcons.Exclamation.Size
         
         ts.ImageList.Images.Add(Me.infoIconKey, SystemIcons.Information)
         
         ts.ImageList.Images.Add(Me.handIconKey, SystemIcons.Hand)
         
         ts.ImageList.Images.Add(Me.exclIconKey, SystemIcons.Exclamation)
         
         ts.ImageList.Images.Add(Me.questionIconKey, SystemIcons.Question)
         
         ts.ImageList.Images.Add(Me.warningIconKey, SystemIcons.Warning)
      End If
    End Sub
   
   
   Private Sub InitializeToolStrip()
      Me.InitializeImageList(Me.toolStrip1)
      
      Me.toolStrip1.Renderer = New RolloverItemRenderer()
      
      Dim item As RolloverItem = Me.CreateRolloverItem(Me.toolStrip1, "RolloverItem on ToolStrip", Me.Font, infoIconKey, TextImageRelation.ImageBeforeText, exclIconKey)
      
      Me.toolStrip1.Items.Add(item)
      
      item = Me.CreateRolloverItem(Me.toolStrip1, "RolloverItem on ToolStrip", Me.Font, infoIconKey, TextImageRelation.ImageBeforeText, exclIconKey)
      
      Me.toolStrip1.Items.Add(item)
    End Sub
   
   
   Private Sub InitializeContextMenu()
      Dim f = New System.Drawing.Font("Arial", 18F, FontStyle.Bold)
      
      Dim cms As New ContextMenuStrip()
      Me.InitializeImageList(cms)
      
      cms.Renderer = New RolloverItemRenderer()
      cms.AutoSize = True
      cms.ShowCheckMargin = False
      cms.ShowImageMargin = False
      
        Dim item As RolloverItem = Me.CreateRolloverItem( _
        cms, _
        "RolloverItem on ContextMenuStrip", _
        f, _
        handIconKey, _
        TextImageRelation.ImageBeforeText, _
        exclIconKey)
      
      cms.Items.Add(item)
      
        item = Me.CreateRolloverItem( _
        cms, _
        "Another RolloverItem on ContextMenuStrip", _
        f, _
        questionIconKey, _
        TextImageRelation.ImageBeforeText, _
        exclIconKey)
      
      cms.Items.Add(item)
      
        item = Me.CreateRolloverItem( _
        cms, _
        "And another RolloverItem on ContextMenuStrip", _
        f, _
        warningIconKey, _
        TextImageRelation.ImageBeforeText, _
        exclIconKey)
      
      cms.Items.Add(item)
      
      AddHandler cms.Closing, AddressOf cms_Closing
      
      Me.button1.ContextMenuStrip = cms
    End Sub
   
   
   ' This method handles the ContextMenuStrip 
   ' control's Closing event. It prevents the 
   ' RolloverItem from closing the drop-down  
   ' when the item is clicked.
   Private Sub cms_Closing(sender As Object, e As ToolStripDropDownClosingEventArgs)
      If e.CloseReason = ToolStripDropDownCloseReason.ItemClicked Then
         e.Cancel = True
      End If
    End Sub
   
   
   ' This method handles the Click event for the button.
   ' it selects the first item in the ToolStrip control
   ' by using the ToolStripITem.Select method.
   Private Sub button1_Click(sender As Object, e As EventArgs) Handles button1.Click
      Dim item As RolloverItem = Me.toolStrip1.Items(0)
      
      If (item IsNot Nothing) Then
         item.Select()
         
         Me.Invalidate()
      End If
    End Sub

   ' This utility method creates a RolloverItem 
   ' and adds it to a ToolStrip control.
    Private Function CreateRolloverItem( _
    ByVal owningToolStrip As ToolStrip, _
    ByVal txt As String, _
    ByVal f As Font, _
    ByVal imgKey As String, _
    ByVal tir As TextImageRelation, _
    ByVal backImgKey As String) As RolloverItem

        Dim item As New RolloverItem()

        item.Alignment = ToolStripItemAlignment.Left
        item.AllowDrop = False
        item.AutoSize = True

        item.BackgroundImage = owningToolStrip.ImageList.Images(backImgKey)
        item.BackgroundImageLayout = ImageLayout.Center
        item.DisplayStyle = ToolStripItemDisplayStyle.ImageAndText
        item.DoubleClickEnabled = True
        item.Enabled = True
        item.Font = f

        ' These assignments are equivalent. Each assigns an
        ' image from the owning toolstrip's image list.
        item.ImageKey = imgKey
        'item.Image = owningToolStrip.ImageList.Images[infoIconKey];
        'item.ImageIndex = owningToolStrip.ImageList.Images.IndexOfKey(infoIconKey);
        item.ImageScaling = ToolStripItemImageScaling.None

        item.Owner = owningToolStrip
        item.Padding = New Padding(2)
        item.Text = txt
        item.TextAlign = ContentAlignment.MiddleLeft
        item.TextDirection = ToolStripTextDirection.Horizontal
        item.TextImageRelation = tir

        Return item
    End Function

   Protected Overrides Sub Dispose(disposing As Boolean)
      If disposing AndAlso (components IsNot Nothing) Then
         components.Dispose()
      End If
      MyBase.Dispose(disposing)
    End Sub
   
   #Region "Windows Form Designer generated code"
   
   Private Sub InitializeComponent()
      Me.toolStrip1 = New System.Windows.Forms.ToolStrip()
      Me.button1 = New System.Windows.Forms.Button()
      Me.SuspendLayout()
      ' 
      ' toolStrip1
      ' 
      Me.toolStrip1.AllowItemReorder = True
      Me.toolStrip1.Location = New System.Drawing.Point(0, 0)
      Me.toolStrip1.Name = "toolStrip1"
      Me.toolStrip1.Size = New System.Drawing.Size(845, 25)
      Me.toolStrip1.TabIndex = 0
      Me.toolStrip1.Text = "toolStrip1"
      ' 
      ' button1
      ' 
      Me.button1.Location = New System.Drawing.Point(12, 100)
      Me.button1.Name = "button1"
      Me.button1.Size = New System.Drawing.Size(86, 23)
      Me.button1.TabIndex = 1
      Me.button1.Text = "Click to select"
      Me.button1.UseVisualStyleBackColor = True
      ' 
      ' RolloverItemTestForm
      ' 
      Me.AutoScaleDimensions = New System.Drawing.SizeF(6F, 14F)
      Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
      Me.AutoSize = True
      Me.ClientSize = New System.Drawing.Size(845, 282)
      Me.Controls.Add(button1)
      Me.Controls.Add(toolStrip1)
        Me.Font = New System.Drawing.Font("Arial", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, 0)
      Me.Name = "RolloverItemTestForm"
      Me.Text = "Form1"
      Me.ResumeLayout(False)
      Me.PerformLayout()
    End Sub
   
#End Region

End Class


Public Class Program

    <STAThread()> _
    Shared Sub Main()
        Application.EnableVisualStyles()
        Application.SetCompatibleTextRenderingDefault(False)
        Application.Run(New RolloverItemTestForm())
    End Sub
End Class

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

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