updatepanel - 更新面板未显示 ASP.NET 3.5 中的错误

Question

在 Visual Studio 2008 中，如果您创建一个新的“Ajax 1.0 Enabled ASP.NET 2.0 Web Application”并粘贴以下代码:

<form id="form1" runat="server">
        <asp:ScriptManager ID="ScriptManager1" runat="server" />
        <div>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
            <ContentTemplate>
                <asp:Button runat="server" ID="foo" Text="click me" onclick="foo_Click" />      
            </ContentTemplate>
        </asp:UpdatePanel>
        </div>
    </form>

背后的代码

protected void foo_Click(object sender, EventArgs e) {
            throw new Exception("hello");
        }

然后单击按钮，您将看到一个 javascript 警报，上面写着“你好”。如果您创建一个 .NET 3.5 Web 应用程序并粘贴相同的代码，则不会再显示任何警报。我错过了什么？

Answer 1

如果您只想修复浏览器 javascript 错误并向用户显示异常消息，则只需将其添加到您的 Masterpage 表单声明之后的某处:

<!-- This script must be placed after the form declaration -->
<script type="text/javascript">
    Sys.Application.add_load(AppLoad);

    function AppLoad() {
        Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequest);
    }

    function EndRequest(sender, args) {
        // Check to see if there's an error on this request.
        if (args.get_error() != undefined) {

            var msg = args.get_error().message.replace("Sys.WebForms.PageRequestManagerServerErrorException: ", "");

            // Show the custom error. 
            // Here you can be creative and do whatever you want
            // with the exception (i.e. call a modalpopup and show 
            // a nicer error window). I will simply use 'alert'
            alert(msg);

            // Let the framework know that the error is handled, 
            //  so it doesn't throw the JavaScript alert.
            args.set_errorHandled(true);
        }
    }
</script>

除非您想自定义消息，否则您不需要捕获 OnAsyncPostBackError。 Go to my blog post if you want more information about this.