莫非是.net一BUG
- HTML code
<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %><asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent"></asp:Content><asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent"> <asp:DropDownList ID="DropDownList3" runat="server" onselectedindexchanged="DropDownList3_SelectedIndexChanged"> <asp:ListItem>choose</asp:ListItem> <asp:ListItem>delete</asp:ListItem> <asp:ListItem>save</asp:ListItem> </asp:DropDownList> <br /> <br /> <br /><asp:Label ID="Label1" runat="server" Text="Label"></asp:Label></asp:Content>
- C# code
using System;using System.Collections.Generic;using System.Linq;using System.Web;using System.Web.UI;using System.Web.UI.WebControls;public partial class _Default : System.Web.UI.Page{ protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { DropDownList3.Attributes.Add("onchange", "if(confirm(\'确认删除吗？\')){__doPostBack( ' " + DropDownList3.ClientID + " ', ' ');}else{return(false);} "); } } protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e) { Label1.Text = "afasfasdfasdf"; } protected void DropDownList3_SelectedIndexChanged(object sender, EventArgs e) { Random ran = new Random(); Label1.Text = "执行了后台事件" + ran.Next().ToString(); }}上述代码可以执行dopostback事件
- HTML code
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %><!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></title></head><body> <form id="form1" runat="server"> <div> <br /> <br /> <br /> <asp:DropDownList ID="DropDownList3" runat="server" onselectedindexchanged="DropDownList3_SelectedIndexChanged"> <asp:ListItem>choose</asp:ListItem> <asp:ListItem>delete</asp:ListItem> <asp:ListItem>save</asp:ListItem> </asp:DropDownList> <br /> <br /> <br /><asp:Label ID="Label1" runat="server" Text="Label"></asp:Label> </div> </form></body></html>
- C# code
public partial class Default2 : System.Web.UI.Page{ protected void Page_Load(object sender, EventArgs e) { if (!Page.IsPostBack) { DropDownList3.Attributes.Add("onchange", "if(confirm(\'确认删除吗？\')){__doPostBack( ' " + DropDownList3.ClientID + " ', ' ');}else{return(false);} "); } } protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e) { Label1.Text = "afasfasdfasdf"; } protected void DropDownList3_SelectedIndexChanged(object sender, EventArgs e) { Random ran = new Random(); Label1.Text = "执行了后台事件" + ran.Next().ToString(); }}
运行时 提示 Microsoft JScript runtime error: '__doPostBack' is undefined
莫非这是一BUG？
[解决办法]
占位
查看页面源码 不一样
[解决办法]
[size=13px][/size]我汗public partial class _Default : System.Web.UI.Page[size=14px][/size][i和public partial class Default2 : System.Web.UI.Page
[解决办法]
什么啊这是，不明白。你的__doPostBack方法在哪里写的？第二个都没看到这个方法在哪里，第一个难道是因为引用了母版页，母版页中有__doPostBack方法才能成功？我猜就是因为MasterPageFile="~/Site.master"中有__doPostBack方法。
[解决办法]
dopastback
是.NET 的服务器控件产生的。 所以要使用此函数，必须整个页面上至少要有一个控件 可以回传页面。有些控件 的autoPostBack 必须设为TRUE。
so this problem is solve. thanks, everyone