海岛奇兵苹果版
742.5M · 2025-12-23
这就是我在原始页面中的内容(在更新面板内))
<asp:Button ID="mmGo" runat="server" Text="Merge" PostBackUrl="~/Default2.aspx?action=merge"/>
然后在下一页我有：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default2.aspx.cs" Inherits="Default2" %>
<%@ PreviousPageType VirtualPath="~/Default.aspx" %>
<!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>
<asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
</div>
</form>
</body>
</html>
…并在.cs文件中：
protected void Page_Load(object sender, EventArgs e)
{
if (PreviousPage != null)
{
string action = Request.QueryString["action"];
if (action == "merge")
{
UpdatePanel SourceControl = (UpdatePanel)PreviousPage.FindControl("UpdatePanel1");
HiddenField SourceTextBox = (HiddenField)SourceControl.FindControl("txtListIDs");
if (SourceTextBox != null)
{
Label1.Text = SourceTextBox.Value;
}
}
}
else
{
Label1.Text = "page is not cross page post back!";
}
}
任何想法为什么PreviousPage总是等于null？
PreviousPage property使用Server.Transfer返回将控件发送到此页面的页面.
If the current page is being rendered as a result of a direct request (not a transfer or cross-post from another page), the PreviousPage property contains null.
