制作图形组合框
效果图：
技术实现：
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;
}
}
}
}