控件DropDownlist中的项目怎么移除不了啊?
有两个DropDownlist控件:dd,dd1
在Page_load中给dd和dd1添加项目。
我在dd_SelectedIndexChanged事件中dd1中的项目,可怎么移除不了
报错“集合已修改;枚举操作可能不会执行。”
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace WebApplication11
{
public class WebForm1 : System.Web.UI.Page
{
protected System.Web.UI.WebControls.DropDownList dd1;
protected System.Web.UI.WebControls.DropDownList dd;
private void Page_Load(object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
ListItem lim =new ListItem ("sdfdsfd","0");
dd.Items.Add (lim);
ListItem lim1 =new ListItem ("123","1");
dd.Items.Add (lim1);
ListItem lim2 =new ListItem ("ee","0");
dd1.Items.Add (lim1);
ListItem lim3 =new ListItem ("ww","1");
dd1.Items.Add (lim);
}
private void dd_SelectedIndexChanged(object sender, System.EventArgs e)
{
foreach(ListItem lim in dd1.Items )
dd1.Items.Remove (lim);
}
}
}