C# 带图片的下拉菜单(combox)

【核心代码】

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

namespace Combox
{
	/// <summary>
	/// Form1 的摘要说明。
	/// </summary>
	public class Form1 : System.Windows.Forms.Form
	{
		private System.Windows.Forms.ComboBox comboBox1;
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Panel panel1;
		/// <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()
		{
			this.comboBox1 = new System.Windows.Forms.ComboBox();
			this.label1 = new System.Windows.Forms.Label();
			this.panel1 = new System.Windows.Forms.Panel();
			this.SuspendLayout();
			// 
			// comboBox1
			// 
			this.comboBox1.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed;
			this.comboBox1.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
			this.comboBox1.Location = new System.Drawing.Point(168, 8);
			this.comboBox1.Name = "comboBox1";
			this.comboBox1.Size = new System.Drawing.Size(152, 22);
			this.comboBox1.TabIndex = 0;
			this.comboBox1.SelectedIndexChanged  = new System.EventHandler(this.comboBox1_SelectedIndexChanged);
			this.comboBox1.MeasureItem  = new System.Windows.Forms.MeasureItemEventHandler(this.comboBox1_MeasureItem);
			this.comboBox1.DrawItem  = new System.Windows.Forms.DrawItemEventHandler(this.comboBox1_DrawItem);
			// 
			// label1
			// 
			this.label1.Location = new System.Drawing.Point(8, 16);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(160, 16);
			this.label1.TabIndex = 1;
			this.label1.Text = "请在组合框中选择颜色值：";
			// 
			// panel1
			// 
			this.panel1.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
			this.panel1.Location = new System.Drawing.Point(8, 40);
			this.panel1.Name = "panel1";
			this.panel1.Size = new System.Drawing.Size(312, 136);
			this.panel1.TabIndex = 2;
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
			this.ClientSize = new System.Drawing.Size(328, 184);
			this.Controls.Add(this.panel1);
			this.Controls.Add(this.label1);
			this.Controls.Add(this.comboBox1);
			this.MaximizeBox = false;
			this.Name = "Form1";
			this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
			this.Text = "演示制作带图形的组合框";
			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)
		{
		//	this.comboBox1.DisplayMember="Color";
			this.comboBox1.Items.Add(Brushes.Cyan);
			this.comboBox1.Items.Add(Brushes.DarkSalmon);
			this.comboBox1.Items.Add(Brushes.Gray);
			this.comboBox1.Items.Add(Brushes.Green);
			this.comboBox1.Items.Add(Brushes.AliceBlue);
			this.comboBox1.Items.Add(Brushes.Black);
			this.comboBox1.Items.Add(Brushes.Blue);
			this.comboBox1.Items.Add(Brushes.Chocolate);
			this.comboBox1.Items.Add(Brushes.Pink);
			this.comboBox1.Items.Add(Brushes.Red);
			this.comboBox1.Items.Add(Brushes.LightBlue);
			this.comboBox1.Items.Add(Brushes.Brown);
			this.comboBox1.Items.Add(Brushes.DodgerBlue);
			this.comboBox1.Items.Add(Brushes.MediumPurple);
			this.comboBox1.Items.Add(Brushes.White);
			this.comboBox1.Items.Add(Brushes.Yellow);			
		}

		private void comboBox1_MeasureItem(object sender, System.Windows.Forms.MeasureItemEventArgs e)
		{//设置列表项宽
			e.ItemHeight=this.comboBox1.ItemHeight-2;			
		}

		private void comboBox1_DrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)
		{//绘制列表项

			ComboBox MyCombox=(ComboBox)sender;
			if(e.Index==-1)
				return;
			if(sender==null)
				return;
			SolidBrush MyBrush=(SolidBrush)MyCombox.Items[e.Index];
			Graphics g=e.Graphics;
			//如果已经进行选择，则绘制正确的背景颜色和聚集框
			e.DrawBackground();
			e.DrawFocusRectangle();
			//绘制颜色的预览框
			Rectangle MyRect=e.Bounds;
			MyRect.Offset(2,2);
			MyRect.Width=50;
			MyRect.Height-=4;
			g.DrawRectangle(new Pen(e.ForeColor),MyRect);
			//获取选定颜色的相应画刷对象，并填充预览框
			MyRect.Offset(1,1);
			MyRect.Width-=2;
			MyRect.Height-=2;
			g.FillRectangle(MyBrush,MyRect);
			//绘制选定颜色的名称
			g.DrawString(MyBrush.Color.Name.ToString(),Font,new SolidBrush(e.ForeColor),e.Bounds.X 60,e.Bounds.Y 1);
		}

		private void comboBox1_SelectedIndexChanged(object sender, System.EventArgs e)
		{//显示选择的颜色
			if(this.comboBox1.SelectedIndex>=0)
			{
				SolidBrush MyBrush=(SolidBrush)(this.comboBox1.SelectedItem);
				this.panel1.BackColor=MyBrush.Color;				
			}			
		}
	}
}