[C#/ASP.NET] ListBox 컨트롤 사용하기

■ ListBox 컨트롤을 사용하는 방법을 보여준다.

▶ MainPage.aspx


<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="MainPage.aspx.cs" Inherits="TestProject.MainPage" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
    <head runat="server">
        <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
        <title>ListBox 컨트롤 사용하기</title>
    </head>
    <body>
        <form id="form" runat="server">
            <div>
                <asp:ListBox ID="listBox" runat="server"
                    SelectionMode="Multiple" />
                <hr />
                <asp:Button ID="printButton" runat="server"
                    Text="출력"
                    OnClick="printButton_Click" />
                <hr />
                <asp:Label ID="displayLabel" runat="server" />
            </div>
        </form>
    </body>
</html>

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="MainPage.aspx.cs" Inherits="TestProject.MainPage" %>

<!DOCTYPE html>

<title>ListBox 컨트롤 사용하기</title>

</head>

<body>

<div>

<asp:ListBox ID="listBox" runat="server"

SelectionMode="Multiple" />

<hr />

<asp:Button ID="printButton" runat="server"

Text="출력"

OnClick="printButton_Click" />

<hr />

<asp:Label ID="displayLabel" runat="server" />

</div>

</form>

</body>

</html>

▶ MainPage.aspx.cs


using System;
using System.Text;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace TestProject
{
    /// <summary>
    /// 메인 페이지
    /// </summary>
    public partial class MainPage : Page
    {
        //////////////////////////////////////////////////////////////////////////////////////////////////// Method
        ////////////////////////////////////////////////////////////////////////////////////////// Protected

        #region 페이지 로드시 처리하기 - Page_Load(sender, e)

        /// <summary>
        /// 페이지 로드시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        protected void Page_Load(object sender, EventArgs e)
        {
            if(!Page.IsPostBack)
            {
                this.listBox.Items.Add("축구");
                this.listBox.Items.Add("농구");

                ListItem listItem = new ListItem();

                listItem.Text  = "배구";
                listItem.Value = "Volleyball";

                this.listBox.Items.Add(listItem);
            }
        }

        #endregion
        #region 출력 버튼 클릭시 처리하기 - printButton_Click(sender, e)

        /// <summary>
        /// 출력 버튼 클릭시 처리하기
        /// </summary>
        /// <param name="sender">이벤트 발생자</param>
        /// <param name="e">이벤트 인자</param>
        protected void printButton_Click(object sender, EventArgs e)
        {
            StringBuilder stringBuilder = new StringBuilder();

            for(int i = 0; i < this.listBox.Items.Count; i++)
            {
                if(this.listBox.Items[i].Selected)
                {
                    stringBuilder.Append(this.listBox.Items[i].Text);

                    if(i != this.listBox.Items.Count - 1)
                    {
                        stringBuilder.Append(",");
                    }
                }
            }

            this.displayLabel.Text = stringBuilder.ToString().TrimEnd(',');
        }

        #endregion
    }
}

using System;

using System.Text;

using System.Web.UI;

using System.Web.UI.WebControls;

namespace TestProject

{

/// <summary>

/// 메인 페이지

/// </summary>

public partial class MainPage : Page

{

//////////////////////////////////////////////////////////////////////////////////////////////////// Method

////////////////////////////////////////////////////////////////////////////////////////// Protected

#region 페이지 로드시 처리하기 - Page_Load(sender, e)

/// <summary>

/// 페이지 로드시 처리하기

/// </summary>

/// <param name="sender">이벤트 발생자</param>

/// <param name="e">이벤트 인자</param>

protected void Page_Load(object sender, EventArgs e)

{

if(!Page.IsPostBack)

{

this.listBox.Items.Add("축구");

this.listBox.Items.Add("농구");

ListItem listItem = new ListItem();

listItem.Text = "배구";

listItem.Value = "Volleyball";

this.listBox.Items.Add(listItem);

}

#endregion

#region 출력 버튼 클릭시 처리하기 - printButton_Click(sender, e)

/// <summary>

/// 출력 버튼 클릭시 처리하기

/// </summary>

/// <param name="sender">이벤트 발생자</param>

/// <param name="e">이벤트 인자</param>

protected void printButton_Click(object sender, EventArgs e)

{

StringBuilder stringBuilder = new StringBuilder();

for(int i = 0; i < this.listBox.Items.Count; i++)

{

if(this.listBox.Items[i].Selected)

{

stringBuilder.Append(this.listBox.Items[i].Text);

if(i != this.listBox.Items.Count - 1)

{

stringBuilder.Append(",");

}

this.displayLabel.Text = stringBuilder.ToString().TrimEnd(',');

}

#endregion

}

TestProject.zip