private void checkedListBox1_SelectedIndexChanged(object sender, EventArgs e)
            {
                this.textBox1.Text=string.Empty;
                foreach (var item in this.checkedListBox1.CheckedItems)
                {
                    this.textBox1.Text += item.ToString() + "\r\n";
                }
            }

------解决方案--------------------


所有Checkbox都调用这一个事件

private void checkBox4_Click(object sender, EventArgs e)
       {
           string txt = "";
           foreach (Control item in Controls)
           {
               if (item is CheckBox)
               {
                   if (((CheckBox)item).Checked)
                       txt += ((CheckBox)item).Text+"\r\n";
                   else
                       txt = txt.Replace(((CheckBox)item).Text, "");
               }
           }
           richTextBox1.Text = txt;
       }

------解决方案--------------------

C# code

 List<string> hbs = new List<string>();
        string hb = string.Empty;

        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
            hb = string.Empty;
            if (this.checkBox1.Checked)
                hbs.Add(this.checkBox1.Text);
            else
                hbs.Remove(this.checkBox1.Text);

            foreach (string s in hbs)
            {
                hb += s;
            }
            this.textBox1.Text = hb;
        }

        private void checkBox2_CheckedChanged(object sender, EventArgs e)
        {
            hb = string.Empty;
            if (this.checkBox2.Checked)
                hbs.Add(this.checkBox2.Text);
            else
                hbs.Remove(this.checkBox2.Text);
            foreach (string s in hbs)
            {
                hb += s;
            }
            this.textBox1.Text = hb;
        }

------解决方案--------------------

写完了，你看一下：
C# code

public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            //注意，所有的checkBox都绑定一个事件就可以了
            checkBox1.CheckedChanged+=new EventHandler(checkBox1_CheckedChanged);
            checkBox2.CheckStateChanged += new EventHandler(checkBox1_CheckedChanged);
            checkBox3.CheckedChanged += new EventHandler(checkBox1_CheckedChanged);
            checkBox4.CheckedChanged += new EventHandler(checkBox1_CheckedChanged);
        }
        List<string> list = new List<string>();
        private void checkBox1_CheckedChanged(object sender, EventArgs e)
        {
            CheckBox cb = sender as CheckBox;
            if (cb != null)
            {
                if (cb.Checked)
                {
                    list.Add(((CheckBox)sender).Text);
                }
                else
                {
                    list.Remove(((CheckBox)sender).Text);
                }
                ShowTxt(list);
            }
           
        }
       
        private void ShowTxt(List<string> list)
        {
            if (list == null || list.Count == 0) return;
            StringBuilder str = new StringBuilder();
            foreach (string s in list)
            {
                str.Append(s);
                str.Append("\r\n");
            }
            textBox1.Text = str.ToString();
        }
    }

------解决方案--------------------