列表框----C#窗体

 using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Text;using System.Windows.Forms; namespace trytry{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }         private void radioButton6_CheckedChanged(object sender, EventArgs e)        {            if (radioButton6.Checked == true) listBox1.MultiColumn = true;        }         private void radioButton5_CheckedChanged(object sender, EventArgs e)        {            if(radioButton5.Checked == true)  listBox1.MultiColumn=false;        }         private void radioButton3_CheckedChanged(object sender, EventArgs e)        {            if (radioButton3.Checked == true)                listBox1.SelectionMode = SelectionMode.MultiSimple;        }         private void listBox1_SelectedIndexChanged(object sender, EventArgs e)        {            label1.Text=""; //如果是单选，则使用SelectedItem返回所选项    if(listBox1.SelectedIndices.Count==1)           label1.Text=listBox1.SelectedItem.ToString();    else{  //如果是多选，则使用SelectedItems返回所有的所选项       for(int i=0;i<listBox1.SelectedIndices.Count;i++)           label1.Text+=listBox1.SelectedItems[i].ToString() + " ";}         }         private void radioButton2_CheckedChanged(object sender, EventArgs e)        {            if (radioButton2.Checked == true)                listBox1.SelectionMode = SelectionMode.One;        }         private void radioButton4_CheckedChanged(object sender, EventArgs e)        {            if (radioButton4.Checked == true)                listBox1.SelectionMode = SelectionMode.MultiExtended;        }         private void radioButton1_CheckedChanged(object sender, EventArgs e)        {            if (radioButton1.Checked == true)                listBox1.SelectionMode = SelectionMode.None;        }    }}