【实例简介】ComboBox 显示图片

【实例截图】

【核心代码】

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Drawing.Drawing2D;

using System.IO;

using System.Net;

using System.Text;

using System.Windows.Forms;

namespace ComboBox_Image

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

//添加项

comboBox1.Items.Add(new MyItem("1111111", this.GetImage("http://www.baidu.com/img/bdlogo.gif")));

comboBox1.Items.Add(new MyItem("2222222", this.GetImage("http://www.baidu.com/img/bdlogo.gif")));

comboBox1.Items.Add(new MyItem("3333333", this.GetImage("http://www.baidu.com/img/bdlogo.gif")));

comboBox1.Items.Add(new MyItem("4444444", this.GetImage("http://www.baidu.com/img/bdlogo.gif")));

comboBox1.Items.Add(new MyItem("5555555", this.GetImage("http://www.baidu.com/img/bdlogo.gif")));

//默认选中项索引

comboBox1.SelectedIndex = 0;

//自绘组合框需要设置的一些属性

comboBox1.DrawMode = DrawMode.OwnerDrawVariable;

comboBox1.DropDownStyle = ComboBoxStyle.DropDownList;

comboBox1.ItemHeight = 30;

comboBox1.Width = 200;

//添加DrawItem事件处理函数

comboBox1.DrawItem = comboBox1_DrawItem;

}

private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)

{

if ((e.State & DrawItemState.Selected) != 0)//鼠标选中在这个项上

{

//渐变画刷

LinearGradientBrush brush = new LinearGradientBrush(e.Bounds, Color.FromArgb(255, 251, 237),

Color.FromArgb(255, 236, 181), LinearGradientMode.Vertical);

//填充区域

Rectangle borderRect = new Rectangle(3, e.Bounds.Y 1, e.Bounds.Width - 5, e.Bounds.Height - 2);

e.Graphics.FillRectangle(brush, borderRect);

//画边框

Pen pen = new Pen(Color.FromArgb(229, 195, 101));

e.Graphics.DrawRectangle(pen, borderRect);

}

else

{

SolidBrush brush = new SolidBrush(Color.FromArgb(217, 223, 230));

e.Graphics.FillRectangle(brush, e.Bounds);

}

//获得项图片,绘制图片

MyItem item = (MyItem)comboBox1.Items[e.Index];

Image img = item.Img;

//图片绘制的区域

Rectangle imgRect = new Rectangle(6, e.Bounds.Y 3, 25, 25);

e.Graphics.DrawImage(img, imgRect);

//文本内容显示区域

Rectangle textRect =

new Rectangle(imgRect.Right 2, imgRect.Y, e.Bounds.Width - imgRect.Width, e.Bounds.Height - 2);

//获得项文本内容,绘制文本

String itemText = comboBox1.Items[e.Index].ToString();

//文本格式垂直居中

StringFormat strFormat = new StringFormat();

strFormat.LineAlignment = StringAlignment.Center;

e.Graphics.DrawString(itemText, new Font("宋体", 12), Brushes.Black, textRect, strFormat);

}

public class MyItem

{

//项文本内容

private String Text;

//项图片

public Image Img;

public MyItem(String text, Image img)

{

Text = text;

Img = img;

}

//重写ToString函数，返回项文本

public override string ToString()

{

return Text;

}

}

public System.Drawing.Image GetImage(string strUrl)

{

try

{

string url = @"http://hiphotos.baidu.com/huyangdiy/pic/item/fd1d340bfaec3e656059f3df.jpg";

url = strUrl;

WebRequest request = WebRequest.Create(url);

WebResponse response = request.GetResponse();

Stream stream = response.GetResponseStream();

Image image = Image.FromStream(stream);

stream.Close();

//g.DrawImage(image, 0, 0);

//g.Dispose();

return image;

}

catch { return null; }

}

}

}