首先是PostBackUrl，像Button、LinkButton等控件都有这个属性。看下面的例子：
Demo.aspx
程序代码 <asp:HiddenField ID="Hidden_ID" runat="server" Value="Test" /> <asp:LinkButton ID="LinkButton1" runat="server" PostBackUrl="Test.aspx">LinkButton</asp:LinkButton> <asp:Button ID="Button1" runat="server" Text="Button" PostBackUrl="Test.aspx" />
Test.aspx.cs
程序代码 protected void Page_Load(object sender, EventArgs e) { if (PreviousPage != null) { HiddenField Hidden_ID = (HiddenField)PreviousPage.FindControl("Hidden_ID"); if (Hidden_ID != null) { Label1.Text = Hidden_ID.Value; } } else { Label1.Text = "null"; } }
Server.Transfer是一个基于服务器的方法，而PostBackUrl是基于客户端的。从这个意义上来讲，跨页面传送比Server.Transfer更加的便捷，有利于提高服务器的性能，减少了处理步骤。除开这一点，两者还是非常相似的，不过在ASP.NET 2.0中，跨页面传送显然是更好的选择。如果要在后续页面中判断PerviousPage所引用的页面是通过跨页面提交而来的还是通过Server.Transfer方法传送而来的，可以通过IsCrossPagePostBack属性来进行判断。
程序代码 if (PreviousPage != null) { if (PreviousPage.IsCrossPagePostBack == true) { Response.Write("Cross-page post."); } } else { Response.Write("Not a cross-page post.");
}
一、用FindControl方法获取发送页的值：
Page1.aspx：
<% @ Page Language = " C# " AutoEventWireup = " true " CodeFile = " Page1.aspx.cs " Inherits = " Page1 " %> <! 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 > Untitled Page </ title > </ head > < body > < form id ="form1" runat ="server" > < div > < asp:TextBox ID ="TextBox1" runat ="server" ></ asp:TextBox > < asp:Calendar ID ="Calendar1" runat ="server" ></ asp:Calendar > < asp:Button ID ="Button1" runat ="server" Text ="Button" PostBackUrl ="~/Page2.aspx" /> </ div > </ form > </ body > </ html >
Page2.aspx.cs:
using System; using System.Collections; using System.Configuration; using System.Data; using System.Web; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; public partial class Page2 : System.Web.UI.Page { protected void Page_Load( object sender, EventArgs e) { TextBox pp_Textbox1; Calendar pp_Calendar1; pp_Textbox1 = (TextBox)PreviousPage.FindControl( " Textbox1 " ); pp_Calendar1 = (Calendar)PreviousPage.FindControl( " Calendar1 " ); Response.Write(pp_Textbox1.Text + " - " + pp_Calendar1.SelectedDate.ToShortDateString()); } }
二、从属性中获得控件的值：
Page1.aspx：
<% @ Page Language = " C# " AutoEventWireup = " true " CodeFile = " Page1.aspx.cs " Inherits = " Page1 " %> <! 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 > Untitled Page </ title > </ head > < body > < form id ="form1" runat ="server" > < div > < asp:TextBox ID ="TextBox1" runat ="server" ></ asp:TextBox > < asp:Calendar ID ="Calendar1" runat ="server" ></ asp:Calendar > < asp:Button ID ="Button1" runat ="server" Text ="Button" onclick ="Button1_Click" PostBackUrl ="~/Page2.aspx" /> </ div > </ form > </ body > </ html > 摘自http://hi.baidu.com/qgbmxxf/blog/item/c51dbe51d34d392a43a75bc5.html
Page2.aspx：
注意使用的是PreviousPageType指令：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Page2.aspx.cs" Inherits="Page2" %>
<%@ PreviousPageType VirtualPath="~/Page1.aspx" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "-
transitional.dtd">
<html xmlns="">
<head runat="server"> <title>Untitled Page</title></head><body> <form id="form1" runat="server"> <div> </div> </form></body></html>
Page2.aspx.cs
using System;
using System.Collections;using System.Configuration;using System.Data;using System.Web;using System.Web.UI;using System.Web.UI.HtmlControls;using System.Web.UI.WebControls; public partial class Page2 : System.Web.UI.Page{ protected void Page_Load(object sender, EventArgs e) { Response.Write(PreviousPage.pp_TextBox1.Text + " - " +PreviousPage.pp_Calendar1.SelectedDate.ToShortDateString());
}}如果在未处理Page1.aspx之前。有人请求了Page2.aspx，该怎么办？使用PreviousPage.IsCrossPagePostBack属性。注意：须先判断
PreviousPage是否为空，否则出报错：未将对象的引用设置到对象的实例
using System;
using System.Collections;using System.Configuration;using System.Data;using System.Web;using System.Web.UI;using System.Web.UI.HtmlControls;using System.Web.UI.WebControls; public partial class Page2 : System.Web.UI.Page{ protected void Page_Load(object sender, EventArgs e) { if (PreviousPage != null) { if (PreviousPage.IsCrossPagePostBack) { Response.Write(PreviousPage.pp_TextBox1.Text + " - " +PreviousPage.pp_Calendar1.SelectedDate.ToShortDateString());
} else { Response.Redirect("Page1.aspx"); }