美化combox 用法 —— 为其添加图片，改变显示方式

对C# 中Combox控件的一些简单的操作，改变其显示特性，主要是改变其中的项的属性

我们需要注意的是：每次为Combox添加项的时候，就会触发DrawItem事件，而我们正是通过DrawItem来改变Combox的显示特性的

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using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Collections;

namespace Combox_Image

{

public partial class Form1 : Form

{

ArrayList brushArray = new ArrayList() ;

ArrayList fontArray = new ArrayList() ;

public Form1()

{

InitializeComponent();

}

private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)

{

//确定画布

Graphics g = e.Graphics;

//绘制区域

Rectangle r = e.Bounds;

Font fn = null;

if (e.Index >= 0)

{

//设置字体、字符串格式、对齐方式

fn = (Font)fontArray[e.Index];

string s = (string)comboBox1.Items[e.Index];

StringFormat sf = new StringFormat();

sf.Alignment = StringAlignment.Near;

//根据不同的状态用不同的颜色表示

if (e.State == (DrawItemState.NoAccelerator | DrawItemState.NoFocusRect))

{

e.Graphics.FillRectangle(new SolidBrush(Color.Red), r);

e.Graphics.DrawString(s, fn, new SolidBrush(Color.Black), r, sf);

e.DrawFocusRectangle();

}

else

{

e.Graphics.FillRectangle(new SolidBrush(Color.LightBlue), r);

e.Graphics.DrawString(s, fn, new SolidBrush(Color.Red), r, sf);

e.DrawFocusRectangle();

}

}

}

private void Form1_Load(object sender, EventArgs e)

{

fontArray.Add(new Font("Ariel", 8, FontStyle.Bold));

fontArray.Add(new Font("Courier", 8, FontStyle.Italic));

fontArray.Add(new Font("Veranda", 8, FontStyle.Bold));

fontArray.Add(new Font("System", 8, FontStyle.Strikeout));

fontArray.Add(new Font("Century SchoolBook", 8, FontStyle.Underline));

fontArray.Add(new Font("Helevctia", 8, FontStyle.Italic));

//创建画刷

brushArray.Add(new SolidBrush(Color.Red));

brushArray.Add(new SolidBrush(Color.Blue));

brushArray.Add(new SolidBrush(Color.Green));

brushArray.Add(new SolidBrush(Color.Yellow));

brushArray.Add(new SolidBrush(Color.Black));

brushArray.Add(new SolidBrush(Color.Azure));

brushArray.Add(new SolidBrush(Color.Firebrick));

brushArray.Add(new SolidBrush(Color.DarkMagenta));

brushArray.Add(new SolidBrush(Color.DarkTurquoise));

brushArray.Add(new SolidBrush(Color.Khaki));

//画comboBox1，注意它要调用comboBox1_DrawItem来画

comboBox1.Items.Add("中国");

comboBox1.Items.Add("巴西");

comboBox1.Items.Add("哥斯达黎加");

comboBox1.Items.Add("土耳其");

comboBox1.Items.Add("韩国");

comboBox1.Items.Add("日本");

//画comboBox2，注意它要调用comboBox2_DrawItem来画

comboBox2.Items.Add("");

comboBox2.Items.Add("");

comboBox2.Items.Add("");

comboBox2.Items.Add("");

comboBox2.Items.Add("");

comboBox2.Items.Add("");

comboBox2.Items.Add("");

comboBox2.Items.Add("");

comboBox2.Items.Add("");

comboBox2.Items.Add("");

//画comboBox3，注意它要调用comboBox3_DrawItem来画

comboBox3.Items.Add("赵微");

comboBox3.Items.Add("舒淇");

comboBox3.Items.Add("谌豹");

comboBox3.Items.Add("郑巧玲");

}

private void comboBox2_DrawItem(object sender, DrawItemEventArgs e)

{

Graphics g = e.Graphics;

Rectangle r = e.Bounds;

if (e.Index >= 0)

{

//设置字符串前矩形块rd的大小

Rectangle rd = r;

rd.Width = rd.Left + 20;

Rectangle rt = r;

r.X = rd.Right;

//用不同的颜色画矩形块

SolidBrush b = (SolidBrush)brushArray[e.Index];

g.FillRectangle(b, rd);

//设置字符串的格式

StringFormat sf = new StringFormat();

sf.Alignment = StringAlignment.Near;

if (e.State == (DrawItemState.NoAccelerator | DrawItemState.NoFocusRect))

{

//字符串背景

e.Graphics.FillRectangle(new SolidBrush(Color.White), r);

//显示字符串

e.Graphics.DrawString(b.Color.Name, new Font("Ariel", 8, FontStyle.Bold), new SolidBrush(Color.Black), r, sf);

//绘制取得焦点时的虚线框

e.DrawFocusRectangle();

}

else

{

e.Graphics.FillRectangle(new SolidBrush(Color.LightBlue), r);

e.Graphics.DrawString(b.Color.Name, new Font("Veranda", 8, FontStyle.Bold), new SolidBrush(Color.Red), r, sf);

e.DrawFocusRectangle();

}

}

}

private void comboBox3_DrawItem(object sender, DrawItemEventArgs e)

{

Graphics g = e.Graphics;

Rectangle r = e.Bounds;

Size imageSize = imageList1.ImageSize;

Font fn = null;

if (e.Index >= 0)

{

fn = (Font)fontArray[0];

string s = (string)comboBox3.Items[e.Index];

StringFormat sf = new StringFormat();

sf.Alignment = StringAlignment.Near;

if (e.State == (DrawItemState.NoAccelerator | DrawItemState.NoFocusRect))

{

//画条目背景

e.Graphics.FillRectangle(new SolidBrush(Color.Red), r);

//绘制图像

imageList1.Draw(e.Graphics, r.Left, r.Top, e.Index);

//显示字符串

e.Graphics.DrawString(s, fn, new SolidBrush(Color.Black), r.Left + imageSize.Width, r.Top);

//显示取得焦点时的虚线框

e.DrawFocusRectangle();

}

else

{

e.Graphics.FillRectangle(new SolidBrush(Color.LightBlue), r);

imageList1.Draw(e.Graphics, r.Left, r.Top, e.Index);

e.Graphics.DrawString(s, fn, new SolidBrush(Color.Black), r.Left + imageSize.Width, r.Top);

e.DrawFocusRectangle();

}

}

}

}

}

三个Combox的效果如下图所示：







原文地址：/article/9101168.html