绑定下拉列表框(dropdownlist)的几种绑定数据的方法

未绑定状态

绑定方法1

单击“确定”完成列表项的添加

看到default.aspx代码如下

<%@ Page Language="C#" AutoEventWireup="true"

CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">

<title>练习1</title>

</head>

<body>

<form id="form1" runat="server">

<div>

&nbsp;

<asp:Button ID="Button1" runat="server" Text="确定"OnClick="Button1_Click" />

<asp:DropDownList ID="DropDownList1" runat="server">

<asp:ListItem>a</asp:ListItem>

<asp:ListItem>b</asp:ListItem>

<asp:ListItem>c</asp:ListItem>

<asp:ListItem>d</asp:ListItem>

<asp:ListItem>e</asp:ListItem>

</asp:DropDownList><br />

<br />

</div>

</form>

</body>

</html>

运行看到

绑定方法2用Dropdownlist1的items集合的Add方法添加项数据在确定按钮的单击事件中添加如下代码protected void Button1_Click(object sender, EventArgs e){this.DropDownList1. Items.Add(new ListItem("11") ) ;this.DropDownList1. Items.Add(new ListItem("22") ) ;this.DropDownList1. Items.Add(new ListItem("33") ) ;this.DropDownList1. Items.Add(new ListItem("44") ) ;this.DropDownList1. Items.Add(new ListItem("55") ) ;}

这样default.aspx.cs中的代码如下using System;using System.Data;using System.Configuration;using System.Web;

using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;public partial class _Default : System.Web.UI.Page

{protected void Page_Load(object sender, EventArgs e)

{

}protected void Button1_Click(object sender, EventArgs e)

{this.DropDownList1. Items.Add(new ListItem("11") ) ;this.DropDownList1. Items.Add(new ListItem("22") ) ;this.DropDownList1. Items.Add(new ListItem("33") ) ;this.DropDownList1. Items.Add(new ListItem("44") ) ;this.DropDownList1. Items.Add(new ListItem("55") ) ;

}

}

运行并单击“确定”按钮后发现列表框中多了11,22,33,44,55

绑定方法3先引入命名空间usingSystem.collections;后定义一个动态数组arraylist su=new arraylist() ;

接着用su.Add("aa") ;给数组添加数据最后用this.dropdownlist1.datasource=su;this.dropdownlist1.databind() ;把数组数据绑定到下拉列表框中default.aspx.cs代码变成如下using System;using System.Data;

using System.Configuration;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.Collections;public partial class _Default : System.Web.UI.Page

{protected void Page_Load(object sender, EventArgs e)

{

}protected void Button1_Click(object sender, EventArgs e)

{this.DropDownList1. Items.Add(new ListItem("11") ) ;this.DropDownList1. Items.Add(new ListItem("22") ) ;this.DropDownList1. Items.Add(new ListItem("33") ) ;this.DropDownList1. Items.Add(new ListItem("44") ) ;this.DropDownList1. Items.Add(new ListItem("55") ) ;

ArrayList su = new ArrayList() ;su.Add("aa") ;su.Add("bb") ;su.Add("cc") ;su.Add("dd") ;su.Add("ee") ;this.DropDownList1.DataSource = su;this.DropDownList1.DataBind() ;

}

}

运行并单击“确定”后看到如下

在设计视图中添加一个文本框实现当我们在下拉列表框中选择某个索引项时立刻在文本框中显示的功能。

要实现这样的功能得先设置服务器回发为真即autopostback为true) ,可以在

属性中找到该属性并设置

然后双击下拉列表控件在其中输入代码

protected void DropDownList1_SelectedIndexChanged(object sender,EventArgs e)

{this.TextBox1.Text = this.DropDownList1.SelectedValue;

}

这时default.aspx.cs代码变成如下using System;using System.Data;using System.Configuration;using System.Web;using System.Web.Security;using System.Web.UI;using System.Web.UI.WebControls;using System.Web.UI.WebControls.WebParts;using System.Web.UI.HtmlControls;using System.Collections;public partial class _Default : System.Web.UI.Page

{protected void Page_Load(object sender, EventArgs e)

{

}protected void Button1_Click(object sender, EventArgs e)

{this.DropDownList1. Items.Add(new ListItem("11") ) ;this.DropDownList1. Items.Add(new ListItem("22") ) ;this.DropDownList1. Items.Add(new ListItem("33") ) ;this.DropDownList1. Items.Add(new ListItem("44") ) ;this.DropDownList1. Items.Add(new ListItem("55") ) ;

ArrayList su = new ArrayList() ;su.Add("aa") ;su.Add("bb") ;su.Add("cc") ;su.Add("dd") ;

su.Add("ee") ;this.DropDownList1.DataSource = su;this.DropDownList1.DataBind() ;

}protected void DropDownList1_SelectedIndexChanged(object sender,EventArgs e)

{this.TextBox1.Text = this.DropDownList1.SelectedValue;

}

}

运行效果如下