创建带图标的ListBoox

作者： 孟宪会 出自： 【孟宪会之精彩世界】 发布日期： 2003-7-25 17:28:53

下面的代码实现了带图标的ListBoox的功能，可以直接拷贝即可运行。运行结果如下：

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace ListBoxWithIcon
{
    /// <summary>
    /// Form1 的摘要说明。
    /// </summary>
    public class Form1 : System.Windows.Forms.Form
    {
        private GListBox lb;
        /// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.Container components = null;

        public Form1()
        {
            //
            // Windows 窗体设计器支持所必需的
            //
            InitializeComponent();

            //
            // TODO: 在 InitializeComponent 调用后添加任何构造函数代码
            //
        }

        /// <summary>
        /// 清理所有正在使用的资源。
        /// </summary>
        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                if (components != null)
                {
                    components.Dispose();
                }
            }
            base.Dispose(disposing);
        }

        #region Windows 窗体设计器生成的代码
        /// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            ImageList imageList = new ImageList();
            imageList.Images.Add(Image.FromFile(@"D:\我的文件\myrice\favicon.ico"));
            imageList.Images.Add(Image.FromFile(@"D:\我的文件\myrice\favicon4.ico"));
            imageList.Images.Add(Image.FromFile(@"D:\我的文件\myrice\favicon5.ico"));

            this.lb = new GListBox(); ;
            this.SuspendLayout();
            //
            // lb
            //
            this.lb.ItemHeight = 16;
            this.lb.Location = new System.Drawing.Point(10, 10);
            this.lb.Name = "listBox1";
            this.lb.Size = new System.Drawing.Size(200, 60);
            this.lb.TabIndex = 0;

            lb.ImageList = imageList;
            lb.Items.Add(new GListBoxItem("http://xml.sz.luohuedu.net/", 0));
            lb.Items.Add(new GListBoxItem("http://lucky.myrice.com/", 1));
            lb.Items.Add(new GListBoxItem("【孟宪会之精彩世界】", 2));

            //
            // Form1
            //
            this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
            this.ClientSize = new System.Drawing.Size(292, 160);
            this.Controls.Add(this.lb);
            this.Text = "带图标的ListBox测试";
            this.Load += new System.EventHandler(this.Form1_Load);
            this.ResumeLayout(false);
        }
        #endregion

        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.Run(new Form1());
        }

        private void Form1_Load(object sender, System.EventArgs e)
        {
        }

        // GListBoxItem 类
        public class GListBoxItem
        {
            private string _myText;
            private int _myImageIndex;
            // 属性
            public string Text
            {
                get { return _myText; }
                set { _myText = value; }
            }
            public int ImageIndex
            {
                get { return _myImageIndex; }
                set { _myImageIndex = value; }
            }
            //构造函数
            public GListBoxItem(string text, int index)
            {
                _myText = text;
                _myImageIndex = index;
            }
            public GListBoxItem(string text) : this(text, -1) { }
            public GListBoxItem() : this("") { }
            public override string ToString()
            {
                return _myText;
            }
        }

        // GListBox 类
        public class GListBox : ListBox
        {
            private ImageList _myImageList;
            public ImageList ImageList
            {
                get { return _myImageList; }
                set { _myImageList = value; }
            }
            public GListBox()
            {
                this.DrawMode = DrawMode.OwnerDrawFixed;
            }
            protected override void OnDrawItem(System.Windows.Forms.DrawItemEventArgs e)
            {
                e.DrawBackground();
                e.DrawFocusRectangle();
                GListBoxItem item;
                Rectangle bounds = e.Bounds;
                Size imageSize = _myImageList.ImageSize;
                try
                {
                    item = (GListBoxItem)Items[e.Index];
                    if (item.ImageIndex != -1)
                    {
                        ImageList.Draw(e.Graphics, bounds.Left, bounds.Top, item.ImageIndex);
                        e.Graphics.DrawString(item.Text, e.Font, new SolidBrush(e.ForeColor),
                          bounds.Left + imageSize.Width, bounds.Top);
                    }
                    else
                    {
                        e.Graphics.DrawString(item.Text, e.Font, new SolidBrush(e.ForeColor),
                          bounds.Left, bounds.Top);
                    }
                }
                catch
                {
                    if (e.Index != -1)
                    {
                        e.Graphics.DrawString(Items[e.Index].ToString(), e.Font,
                          new SolidBrush(e.ForeColor), bounds.Left, bounds.Top);
                    }
                    else
                    {
                        e.Graphics.DrawString(Text, e.Font, new SolidBrush(e.ForeColor),
                          bounds.Left, bounds.Top);
                    }
                }
                base.OnDrawItem(e);
            }
        }
    }
}