ToolStripItem ToolStripItem ToolStripItem ToolStripItem Class

定義

public ref class ToolStripItem abstract : System::ComponentModel::Component, IDisposable, System::Windows::Forms::IDropTarget

public abstract class ToolStripItem : System.ComponentModel.Component, IDisposable, System.Windows.Forms.IDropTarget

type ToolStripItem = class
    inherit Component
    interface IDropTarget
    interface IComponent
    interface IDisposable

Public MustInherit Class ToolStripItem
Inherits Component
Implements IDisposable, IDropTarget

繼承

ObjectObjectObjectObject

MarshalByRefObjectMarshalByRefObjectMarshalByRefObjectMarshalByRefObject

ComponentComponentComponentComponent

ToolStripItemToolStripItemToolStripItemToolStripItem

衍生

ToolStripButtonToolStripButtonToolStripButtonToolStripButton

ToolStripControlHostToolStripControlHostToolStripControlHostToolStripControlHost

ToolStripDropDownItemToolStripDropDownItemToolStripDropDownItemToolStripDropDownItem

ToolStripLabelToolStripLabelToolStripLabelToolStripLabel

ToolStripSeparatorToolStripSeparatorToolStripSeparatorToolStripSeparator

實作

IComponentIComponentIComponentIComponent IDisposableIDisposableIDisposableIDisposable IDropTargetIDropTargetIDropTargetIDropTarget

範例

下列程式碼範例示範如何實作自訂ToolStripItem控制項。The following code example demonstrates how to implement a custom ToolStripItem control.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

namespace RolloverItemDemoLib
{
    // This class implements a ToolStripItem that highlights
    // its border and text when the mouse 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 : ToolStripItem
    {
        private bool clickedValue = false;
        private bool rolloverValue = false;

        private Rectangle imageRect;
        private Rectangle textRect;

        // For brevity, this implementation limits the possible 
        // TextDirection values to ToolStripTextDirection.Horizontal. 
        public override ToolStripTextDirection TextDirection
        {
            get
            {
                return base.TextDirection;
            }
            set
            {
                if (value == ToolStripTextDirection.Horizontal)
                {
                    base.TextDirection = value;
                }
                else
                {
                    throw new ArgumentException(
                        "RolloverItem supports only horizontal text.");
                }
            }
        }

        // For brevity, this implementation limits the possible 
        // TextImageRelation values to ImageBeforeText and TextBeforeImage. 
        public new TextImageRelation TextImageRelation
        {
            get
            {
                return base.TextImageRelation;
            }

            set
            {
                if (value == TextImageRelation.ImageBeforeText || 
                    value == TextImageRelation.TextBeforeImage)
                {
                    base.TextImageRelation = value;
                }
                else
                {
                    throw new ArgumentException(
                        "Unsupported TextImageRelation value.");
                }
            }
        }
        
        // This property returns true if the mouse is 
        // inside the client rectangle.
        public bool Rollover
        {
            get
            {
                return this.rolloverValue;
            }   
        }

        // This property returns true if the item 
        // has been toggled into the clicked state.
        // Clicking again toggles it to the 
        // unclicked state.
        public bool Clicked
        {
            get
            {
                return this.clickedValue;
            }
        }

        // The method defines the behavior of the Click event.
        // It simply toggles the state of the clickedValue field.
        protected override void OnClick(EventArgs e)
        {
            base.OnClick(e);

            this.clickedValue ^= true;
        }

        // The method defines the behavior of the DoubleClick 
        // event. It shows a MessageBox with the item's text.
        protected override void OnDoubleClick(EventArgs e)
        {
            base.OnDoubleClick(e);

            string msg = String.Format("Item: {0}", this.Text);

            MessageBox.Show(msg);
        }

        // 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 override void OnMouseEnter(EventArgs e)
        {
            base.OnMouseEnter(e);

            this.rolloverValue = true;

            this.Invalidate();
        }

        // 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 override void OnMouseLeave(EventArgs e)
        {
            base.OnMouseLeave(e);

            this.rolloverValue = false;

            this.Invalidate();
        }

        // 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 override void OnPaint(PaintEventArgs e)
        {
            base.OnPaint(e);

            if (this.Owner != null)
            {
                // Find the dimensions of the image and the text 
                // areas of the item. 
                this.ComputeImageAndTextLayout();

                // Draw the background. This includes drawing a highlighted 
                // border when the mouse is in the client area.
                ToolStripItemRenderEventArgs ea = new ToolStripItemRenderEventArgs(
                     e.Graphics,
                     this);
                this.Owner.Renderer.DrawItemBackground(ea);

                // Draw the item's image. 
                ToolStripItemImageRenderEventArgs irea =
                    new ToolStripItemImageRenderEventArgs(
                    e.Graphics,
                    this,
                    imageRect );
                this.Owner.Renderer.DrawItemImage(irea);

                // If the item is on a drop-down, give its
                // text a different highlighted color.
                Color highlightColor = 
                    this.IsOnDropDown ?
                    Color.Salmon : SystemColors.ControlLightLight;

                // Draw the text, and highlight it if the 
                // the rollover state is true.
                ToolStripItemTextRenderEventArgs rea =
                    new ToolStripItemTextRenderEventArgs(
                    e.Graphics,
                    this,
                    base.Text,
                    textRect,
                    this.rolloverValue ? highlightColor : base.ForeColor,
                    base.Font,
                    base.TextAlign);
                this.Owner.Renderer.DrawItemText(rea);
            }
        }

        // 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 void ComputeImageAndTextLayout()
        {
            Rectangle cr = base.ContentRectangle;
            Image img = base.Owner.ImageList.Images[base.ImageKey];

            // Compute the center of the item's ContentRectangle.
            int centerY = (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 (base.TextImageRelation == TextImageRelation.ImageBeforeText &&
                base.TextDirection == ToolStripTextDirection.Horizontal)
            {
                imageRect = new Rectangle(
                    base.ContentRectangle.Left,
                    centerY,
                    base.Image.Width,
                    base.Image.Height);

                textRect = new Rectangle(
                    imageRect.Width,
                    base.ContentRectangle.Top,
                    base.ContentRectangle.Width - imageRect.Width,
                    base.ContentRectangle.Height);
            }
            else if (base.TextImageRelation == TextImageRelation.TextBeforeImage &&
                     base.TextDirection == ToolStripTextDirection.Horizontal)
            {
                imageRect = new Rectangle(
                    base.ContentRectangle.Right - base.Image.Width,
                    centerY,
                    base.Image.Width,
                    base.Image.Height);

                textRect = new Rectangle(
                    base.ContentRectangle.Left,
                    base.ContentRectangle.Top,
                    imageRect.X,
                    base.ContentRectangle.Bottom);
            }
        }
    }

    #region RolloverItemRenderer

    // 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.
    internal class RolloverItemRenderer : ToolStripSystemRenderer
    {
        protected override void OnRenderItemImage(
            ToolStripItemImageRenderEventArgs e)
        {
            base.OnRenderItemImage(e);

            RolloverItem item = e.Item as RolloverItem;

            // If the ToolSTripItem is of type RolloverItem, 
            // perform custom rendering for the image.
            if (item != null)
            {
                if (item.Clicked)
                {
                    // 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);
                }
            }
        }

        // 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 override void OnRenderItemBackground(
            ToolStripItemRenderEventArgs e)
        {
            base.OnRenderItemBackground(e);

            RolloverItem item = e.Item as RolloverItem;

            // If the ToolSTripItem is of type RolloverItem, 
            // perform custom rendering for the background.
            if (item != null)
            {
                if (item.Placement == ToolStripItemPlacement.Overflow ||
                    item.IsOnDropDown)
                {
                    using (LinearGradientBrush b = new LinearGradientBrush(
                        item.ContentRectangle,
                        Color.Salmon,
                        Color.DarkRed,
                        0f,
                        false))
                    {
                        e.Graphics.FillRectangle(b, item.ContentRectangle);
                    }
                }

                // The RolloverItem control only supports 
                // the ImageLayout.Center setting for the
                // BackgroundImage property.
                if (item.BackgroundImageLayout == ImageLayout.Center)
                {
                    // Get references to the item's ContentRectangle
                    // and BackgroundImage, for convenience.
                    Rectangle cr = item.ContentRectangle;
                    Image bgi = item.BackgroundImage;

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

                    // If the item is selected, draw the background
                    // image as usual. Otherwise, draw it as disabled.
                    if (item.Selected)
                    {
                        e.Graphics.DrawImage(bgi, centerX, centerY);
                    }
                    else
                    {
                        ControlPaint.DrawImageDisabled(
                                e.Graphics,
                                bgi,
                                centerX,
                                centerY,
                                item.BackColor);
                    }
                }

                // If the item is in the rollover state, 
                // draw a border around it.
                if (item.Rollover)
                {
                    ControlPaint.DrawFocusRectangle(
                        e.Graphics,
                        item.ContentRectangle);
                }
            }
        }

    #endregion

    }

    // 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 : Form
    {
        private System.Windows.Forms.ToolStrip toolStrip1;
        private System.Windows.Forms.Button button1;

        private string infoIconKey = "Information icon";
        private string handIconKey = "Hand icon";
        private string exclIconKey = "Exclamation icon";
        private string questionIconKey = "Question icon";
        private string warningIconKey = "Warning icon ";

        private System.ComponentModel.IContainer components = null;

        public RolloverItemTestForm()
        {
            InitializeComponent();

            // Set up the form's ToolStrip control.
            InitializeToolStrip();

            // Set up the ContextMenuStrip for the button.
            InitializeContextMenu();
        }

        // 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 void InitializeImageList(ToolStrip ts)
        {
            if (ts.ImageList == null)
            {
                ts.ImageList = new ImageList();
                ts.ImageList.ImageSize = SystemIcons.Exclamation.Size;

                ts.ImageList.Images.Add(
                    this.infoIconKey,
                    SystemIcons.Information);

                ts.ImageList.Images.Add(
                    this.handIconKey,
                    SystemIcons.Hand);

                ts.ImageList.Images.Add(
                    this.exclIconKey,
                    SystemIcons.Exclamation);

                ts.ImageList.Images.Add(
                    this.questionIconKey,
                    SystemIcons.Question);

                ts.ImageList.Images.Add(
                    this.warningIconKey,
                    SystemIcons.Warning);
            }
        }

        private void InitializeToolStrip()
        {
            this.InitializeImageList(this.toolStrip1);

            this.toolStrip1.Renderer = new RolloverItemRenderer();

            RolloverItem item = this.CreateRolloverItem(
                this.toolStrip1,
                "RolloverItem on ToolStrip",
                this.Font,
                infoIconKey,
                TextImageRelation.ImageBeforeText,
                exclIconKey);

            this.toolStrip1.Items.Add(item);

            item = this.CreateRolloverItem(
                this.toolStrip1,
                "RolloverItem on ToolStrip",
                this.Font,
                infoIconKey,
                TextImageRelation.ImageBeforeText,
                exclIconKey);

            this.toolStrip1.Items.Add(item);
        }

        private void InitializeContextMenu()
        {
            Font f = new System.Drawing.Font(
                "Arial",
                18f,
                FontStyle.Bold);

            ContextMenuStrip cms = new ContextMenuStrip();
            this.InitializeImageList(cms);

            cms.Renderer = new RolloverItemRenderer();
            cms.AutoSize = true;
            cms.ShowCheckMargin = false;
            cms.ShowImageMargin = false;

            RolloverItem item = this.CreateRolloverItem(
                cms,
                "RolloverItem on ContextMenuStrip",
                f,
                handIconKey,
                TextImageRelation.ImageBeforeText,
                exclIconKey);

            cms.Items.Add(item);

            item = this.CreateRolloverItem(
                cms,
                "Another RolloverItem on ContextMenuStrip",
                f,
                questionIconKey,
                TextImageRelation.ImageBeforeText,
                exclIconKey);

            cms.Items.Add(item);

            item = this.CreateRolloverItem(
                cms,
                "And another RolloverItem on ContextMenuStrip",
                f,
                warningIconKey,
                TextImageRelation.ImageBeforeText,
                exclIconKey);

            cms.Items.Add(item);

            cms.Closing += new ToolStripDropDownClosingEventHandler(cms_Closing);

            this.button1.ContextMenuStrip = cms;
        }

        // This method handles the ContextMenuStrip 
        // control's Closing event. It prevents the 
        // RolloverItem from closing the drop-down  
        // when the item is clicked.
        void cms_Closing(object sender, ToolStripDropDownClosingEventArgs e)
        {
            if (e.CloseReason == ToolStripDropDownCloseReason.ItemClicked)
            {
                e.Cancel = true;
            }
        }

        // 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 void button1_Click(object sender, EventArgs e)
        {
            RolloverItem item = this.toolStrip1.Items[0] as RolloverItem;

            if (item != null)
            {
                item.Select();

                this.Invalidate();
            }
        }

        // This utility method creates a RolloverItem 
        // and adds it to a ToolStrip control.
        private RolloverItem CreateRolloverItem(
            ToolStrip owningToolStrip,
            string txt,
            Font f,
            string imgKey,
            TextImageRelation tir,
            string backImgKey)
        {
            RolloverItem item = 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;
        }

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

        #region Windows Form Designer generated code

        private void InitializeComponent()
        {
            this.toolStrip1 = new System.Windows.Forms.ToolStrip();
            this.button1 = new System.Windows.Forms.Button();
            this.SuspendLayout();
            // 
            // toolStrip1
            // 
            this.toolStrip1.AllowItemReorder = true;
            this.toolStrip1.Location = new System.Drawing.Point(0, 0);
            this.toolStrip1.Name = "toolStrip1";
            this.toolStrip1.Size = new System.Drawing.Size(845, 25);
            this.toolStrip1.TabIndex = 0;
            this.toolStrip1.Text = "toolStrip1";
            // 
            // button1
            // 
            this.button1.Location = new System.Drawing.Point(12, 100);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(86, 23);
            this.button1.TabIndex = 1;
            this.button1.Text = "Click to select";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // 
            // RolloverItemTestForm
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 14F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.AutoSize = true;
            this.ClientSize = new System.Drawing.Size(845, 282);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.toolStrip1);
            this.Font = new System.Drawing.Font("Arial", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
            this.Name = "RolloverItemTestForm";
            this.Text = "Form1";
            this.ResumeLayout(false);
            this.PerformLayout();

        }

        #endregion
    }

    static class Program
    {   
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new RolloverItemTestForm());
        }
    }

}

Option Strict On
Option Explicit On

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 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 = Me.clickedValue Xor 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 = CType(IIf(Me.IsOnDropDown, Color.Salmon, SystemColors.ControlLightLight), Color)
         
         ' Draw the text, and highlight it if the 
         ' the rollover state is true.
            Dim rea As New ToolStripItemTextRenderEventArgs( _
               e.Graphics, _
               Me, _
               MyBase.Text, _
               textRect, _
               CType(IIf(Me.rolloverValue, highlightColor, MyBase.ForeColor), Color), _
               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 = CInt((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 = CType(e.Item, RolloverItem)

        ' 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 = CType(e.Item, RolloverItem)

        ' 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 = CInt((cr.Width - bgi.Width) / 2)
                Dim centerY As Integer = CInt((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 As New System.Drawing.Font("Arial", 18.0F, 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", _
        CType(f, Drawing.Font), _
        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 = CType(Me.toolStrip1.Items(0), RolloverItem)
      
      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

備註

AToolStripItem是項目，例如按鈕、 下拉式方塊、 文字方塊中或可以包含在的標籤ToolStrip控制或ToolStripDropDown控制項，類似於 Windows 快顯功能表。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. ToolStrip類別會管理繪製和鍵盤和滑鼠輸入，並拖曳輸入，針對這些項目，包括和ToolStripItem類別會管理事件和配置項目本身內。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 類別是直接繼承自ToolStripItem，或它們間接繼承自ToolStripItem透過ToolStripControlHost或ToolStripDropDownItem。ToolStripItem classes either inherit directly from ToolStripItem, or they inherit indirectly from ToolStripItem through ToolStripControlHost or ToolStripDropDownItem.

ToolStripItem 控制項必須包含在ToolStrip， MenuStrip， StatusStrip，或ContextMenuStrip並無法直接加入至表單。ToolStripItem controls must be contained in a ToolStrip, MenuStrip, StatusStrip, or ContextMenuStrip and cannot be added directly to a form. 各種不同的容器類別設計成包含適當的子集ToolStripItem控制項。The various container classes are designed to contain an appropriate subset of ToolStripItem controls.

附註給定ToolStripItem不能有多個父系ToolStrip。Note A given ToolStripItem cannot have more than one parent ToolStrip. 您必須將複製的ToolStripItem並將它新增至其他ToolStrip控制項。You must copy of the ToolStripItem and add it to other ToolStrip controls.

下表顯示的項目衍生自ToolStripItem類別，以及哪些因此可以裝載於ToolStrip或ToolStripDropDown。The following table shows the elements that derive from the ToolStripItem class and which therefore can be hosted in a ToolStrip or ToolStripDropDown.

建構函式

屬性

方法

事件

明確介面實作

適用於

另請參閱

• ToolStrip ToolStrip ToolStrip ToolStrip
• ToolStripButton ToolStripButton ToolStripButton ToolStripButton
• ToolStripLabel ToolStripLabel ToolStripLabel ToolStripLabel
• ToolStripSeparator ToolStripSeparator ToolStripSeparator ToolStripSeparator
• ToolStripControlHost ToolStripControlHost ToolStripControlHost ToolStripControlHost
• ToolStripComboBox
• ToolStripTextBox
• ToolStripDropDownItem ToolStripDropDownItem ToolStripDropDownItem ToolStripDropDownItem
• ToolStripMenuItem
• ToolStripSplitButton
• ToolStripDropDownButton
• ToolStrip 控制項 (Windows Form)ToolStrip Control (Windows Forms)