ASP.NET AJAX(27)-AsyncPostBackError

2008-03-16

這一篇來講一下如何來補抓非同步postback時，所發生的一些error

.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Untitled Page</title> </head> <body> <form id="form1" runat="server"> <asp:ScriptManager ID="ScriptManager1" runat="server" OnAsyncPostBackError="ScriptManager1_AsyncPostBackError" /> <div> <asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional"> <ContentTemplate> <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Button" /> </ContentTemplate> </asp:UpdatePanel> </div> <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="Button" /> </form> </body> </html>

.aspx.cs

using System; using System.Data; using System.Configuration; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { ScriptManager.GetCurrent(this).RegisterAsyncPostBackControl(Button2); } protected void ScriptManager1_AsyncPostBackError(object sender, AsyncPostBackErrorEventArgs e) { this.ScriptManager1.AsyncPostBackErrorMessage = "錯誤原因：" + e.Exception.Message; } protected void Button1_Click(object sender, EventArgs e) { throw new Exception("資料庫1連線失敗"); } protected void Button2_Click(object sender, EventArgs e) { throw new Exception("資料庫2連線失敗"); } }

1.首先執行這個例子前，先記得不要進入偵錯模式，也就是不偵錯執行

2.當button在updatepanal裡時，所丟出的例外事件，其實scriptmanager本身就會以對話方塊去顯示出補抓到的錯誤

3.可以先將ScriptManager.GetCurrent(this).RegisterAsyncPostBackControl(Button2);這行註解掉，並按一下button2，此時會出現錯誤畫面，要如何使不在updatepanal裡的button，也可以用對話方塊展示出錯誤訊息呢?在load事件加上以上那行即可

4.AsyncPostBackError事件可以讓我們對錯誤訊息的對話方塊多加一點說明

5.在非同步postback發生錯誤訊息時，如何轉至別的頁面?在webconfig中轉址過去要顯示的頁面即可

<system.web> <customErrors defaultRedirect="http://www.yahoo.com.tw" mode="On"></customErrors> </system.web>

回首頁