Page losing title after UpdatePanel asyncpostback

问题

I have just noticed recently that my page title will reset to the standard "Untitled Page" after I perform an asyncpostback from inside my UpdatePanel in the main page. The title will not be lost during a postback from inside the master page (such as when I click on the search box button inside the master page).

I assumed that by using a different contentplaceholder specifically for setting the document title I was going to avoid issues like this, but apparently I was wrong. Is there something else I am missing other than having to explicitly set the title in the code-behind of the ASPX page (which I was hoping to avoid with the way it was setup below)?

Here is the basic gist of my page which is calling the Master Page (master page code below)

<asp:Content ID="Content1" ContentPlaceHolderID="title" Runat="Server">
    Page Title
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="head" Runat="Server">
    <script type="text/javascript">
        //random javascript validators
    </script>   
</asp:Content>
<asp:Content ID="Content3" ContentPlaceHolderID="content" Runat="Server">
    <div class="title">
        Account Management
    </div>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            //Username + Password Set Form
        </ContentTemplate>       
    </asp:UpdatePanel>

</asp:Content>

This is the of the Master Page. The ASP.NET AJAX ScriptManager is placed first thing after the <form> tag in the body.

<head id="Head1" runat="server">
    <title>
        <asp:ContentPlaceHolder id="title" runat="server">
        </asp:ContentPlaceHolder>
    </title>
        //Stylesheet references

    <script type="text/javascript">
        //Random javascript functions
    </script>

    <asp:ContentPlaceHolder id="head" runat="server">
    </asp:ContentPlaceHolder>
</head>

回答1:

Are you opposed to using the Title property of the Content Page?

<%@ Page Title="Your Page Title" Language="vb" AutoEventWireup="false" MasterPageFile="~/MasterPages/...

You can also access this programmatically in the page load...

回答2:

We ran into this exact issue on one of our sites.

The immediate fix was to reset the title in the master page codebehind page_load method.

Apparently when the ajax call occurs, it is rerunning the master page. This was causing our title to disappear.

For example:

protected void Page_Load(object sender, EventArgs e) {
    this.Page.Title = "whatever title you have...";
}

A better fix is to drop the MS updatepanel crap and start using JSON / jQuery where you actually have some decent control over the calls.

回答3:

Is a weird bug that can be workedaround if you remove the spaces in the title tag like:

<title><asp:ContentPlaceHolder id="title" runat="server"></asp:ContentPlaceHolder></title>

Tested on Sharepoint 2010

回答4:

Rather than change your server side code, why not just fix it in JS:

$(function(){
    var prm = Sys.WebForms.PageRequestManager.getInstance();
    if (!(prm)) return;
    document.orginalTitle=document.title;
    prm.add_endRequest(function(s, e){
        if (document.title.replace(/\s/g,"").length==0)
            document.title=document.orginalTitle;
        });
});

回答5:

It happens when you set the title progammatically and only when is not PostBack. Just rewrite save/load postback methods to hold the title in the viewstate bag.

    protected override void LoadViewState(object savedState)
    {
        object[] allStates = (object[])savedState;
        if (allStates[0] != null)
            base.LoadViewState(allStates[0]);
        if (allStates[1] != null)
            Page.Title = (string)allStates[1];
    }

    protected override object SaveViewState()
    {
        object[] allStates = new object[2];
        object baseState = base.SaveViewState();
        string pageTitle = Page.Title;
        allStates[0] = baseState;
        allStates[1] = pageTitle;
        return allStates;
    }

回答6:

You could put the Page title in Viewstate and then just grab the string in the button postback Click event and assign it to Page.Title

    public string MyPageTitle
    {
        get
        {
            return (string)ViewState["MyPageTitle"];
        }
        set
        {
            ViewState["MyPageTitle"] = value;
        }
    }

On Page load assign: MyPageTitle = "My Cool Web Page Title"; Then in button click event:

protected void MyLinkButton_Click(object sender, EventArgs e)
    {

       Page.Title = MyPageTitle;

    }

来源：https://stackoverflow.com/questions/627378/page-losing-title-after-updatepanel-asyncpostback

标签

ASP.NET

asp.net-ajax

master-pages