【C#】简单自绘带图片的 ComboBox

先看看效果：

 

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先构造一个子项的类：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Drawing;//



namespace ComboBox_Draw

{

    //自定义组合框项

    class MyItem

    {

        //项文本内容

        private String Text;

       

        //项图片

        public Image Img;



        //构造函数

        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;

        }

    }

}

 

然后看重写DrawItem事件：

private void ComboBox1_DrawItem(object sender, DrawItemEventArgs e)

        {

            //鼠标选中在这个项上

            if ((e.State & DrawItemState.Selected) != 0)

            {

                //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, 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(255, 255, 255));

                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, 45,45);

            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("微软雅黑", 12), Brushes.Black, textRect, strFormat);

        }

 

最后是窗体Load事件：最后是窗体Load事件：

 

        private void Form1_Load(object sender, EventArgs e)

        {

            //添加项

            comboBox1.Items.Add(new MyItem("000000", Image.FromFile(Application.StartupPath + "\\0.gif")));

            comboBox1.Items.Add(new MyItem("111111", Image.FromFile(Application.StartupPath + "\\1.gif")));

            comboBox1.Items.Add(new MyItem("222222", Image.FromFile(Application.StartupPath + "\\2.gif")));

            comboBox1.Items.Add(new MyItem("333333", Image.FromFile(Application.StartupPath + "\\3.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.OwnerDrawFixed;

            comboBox1.DropDownStyle = ComboBoxStyle.DropDownList;

            comboBox1.ItemHeight = 50;

            comboBox1.Width = 200;



            //添加DrawItem事件处理函数

            comboBox1.DrawItem += ComboBox1_DrawItem;



        }

 

 

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