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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)

public abstract class ToolStripItem : Component, 
	IDropTarget, IComponent, IDisposable

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.

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());
        }
    }

}

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 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0
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