Question

C# checkedListBox控件选项被选中后,背景色可否不变

如图片,选择7被点击后背景色改变,
能否不改变背景色

Answer 1

为了你这个问题想了很多，没有分真是浪费时间了。好了，好人做到底，我给你我忙了后的代码，其实就是重写OnDrawItem而已。

这个是FORM1，其中Form1.Designer.cs为空代码。下图演示就是选中时为背景为透明色

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        private System.ComponentModel.IContainer components = null;
        private ColorCodedCheckedListBox checkedListBox1;
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }
        private void InitializeComponent()
        {
            this.checkedListBox1 = new WindowsFormsApplication2.ColorCodedCheckedListBox();
            this.SuspendLayout();
            this.checkedListBox1.FormattingEnabled = true;
            this.checkedListBox1.Items.AddRange(new object[] {"选项1","选项2"});
            this.checkedListBox1.Location = new System.Drawing.Point(12, 12);
            this.checkedListBox1.Name = "checkedListBox1";
            this.checkedListBox1.Size = new System.Drawing.Size(128, 36);
            this.checkedListBox1.TabIndex = 0;
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(164, 67);
            this.Controls.Add(this.checkedListBox1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);
        }
    }
    class ColorCodedCheckedListBox : CheckedListBox
    {
        //Color.Orange为颜色，你可修改
        protected override void OnDrawItem(DrawItemEventArgs e)
        {
            DrawItemEventArgs e2 = new DrawItemEventArgs(e.Graphics, e.Font, new Rectangle(e.Bounds.Location, e.Bounds.Size), e.Index, (e.State & DrawItemState.Focus) == DrawItemState.Focus ? DrawItemState.Focus : DrawItemState.None, Color.Orange, this.BackColor);
            base.OnDrawItem(e2);
        }
    }
}