Asp.net中ListBox的用法！

绝地灬酷狼 2022-05-27 12:20 152阅读 0赞

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Web;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Collections;
    
    namespace Vocation
    {
        public partial class WebForm1 : System.Web.UI.Page
        {
            protected void Page_Load(object sender, EventArgs e)
            {
                if (!IsPostBack)
                {
                    ArrayList a = new ArrayList();
                    a.Add("asp.net");
                    a.Add("JavaScript");
                    a.Add("CSS");
                    a.Add("Html");
                    a.Add("C#");
                    ListBox2.DataSource = a;
                    ListBox2.DataBind();
                }
    
            }
    
            protected void Button1_Click(object sender, EventArgs e)
            {
                foreach (ListItem item in ListBox2.Items)
                {
                    ListBox3.Items.Add(item);
                   
    
                }
                ListBox2.Items.Clear();
            }
    
            protected void Button3_Click(object sender, EventArgs e)
            {
    
                foreach (ListItem item in ListBox3.Items)
                {
                    ListBox2.Items.Add(item);
                   
    
                }
                ListBox3.Items.Clear();
            }
    
            protected void Button2_Click(object sender, EventArgs e)
            {
               //左边------右边
                if (ListBox2.SelectedIndex != -1)
                {
                    foreach (ListItem item in ListBox2.Items)
                    {
                        if (item.Selected)
                        {
                            ListBox3.Items.Add(item);
                        }
    
                    }
                }
                for (int index = ListBox2.Items.Count-1; index>=0; index--)
                {
                    if (ListBox2.Items[index].Selected)
                    {
                        ListBox2.Items.RemoveAt(index);
                    }
                }
    
                
            }
    
            protected void Button4_Click(object sender, EventArgs e)
            {
                if (ListBox3.SelectedIndex != -1)
                {
                    foreach (ListItem item in ListBox3.Items)
                    {
                        if (item.Selected)
                        {
                            ListBox2.Items.Add(item);
                        }
    
                    }
                }
                for (int index = ListBox3.Items.Count - 1; index >= 0; index--)
                {
                    if (ListBox3.Items[index].Selected)
                    {
                        ListBox3.Items.RemoveAt(index);
                    }
                }
            }
    
            protected void Button5_Click(object sender, EventArgs e)
            {
                Label1.Text = "你选择的科目为：";
                foreach(ListItem item in ListBox3.Items)
                {
                    Label1.Text+=item.Text +" ";
                }
                
            }
        }
    }

![1348112394_8199.jpg][]

值得注意的是在WEB控件中，listbox的selecteditem并不是指的当前选定的值，而是最小值，这点与winform不同。所以在上面没有用selecteditem来取值，而是遍历后用item.text

[1348112394_8199.jpg]: https://img-my.csdn.net/uploads/201209/20/1348112394_8199.jpg