RadAjaxManager AJAX请求大约有10%的时间失败

Question

我有一个Web应用程序,当用户在我的一个页面上进行选择时,它使用RadAjaxManager来填充RadComboBox控件.这在大多数情况下都能正常工作,但是大约有10%的时间AJAX调用似乎触发但没有值加载到目标RadComboBox中.如果浏览器关闭并再次访问该页面,则此行为似乎仍在继续,但几分钟后,另一个浏览器刷新一切正常.

以下是启动AJAX请求的RadComboBox的Ajax设置:

<telerik:AjaxSetting AjaxControlID="rcmbMarket">
        <UpdatedControls>
            <telerik:AjaxUpdatedControl ControlID="rcmbApplicationField" 
                LoadingPanelID="RadAjaxLoadingPanel1" />
            <telerik:AjaxUpdatedControl ControlID="ApplicationFieldSource" 
                LoadingPanelID="RadAjaxLoadingPanel1" />
        </UpdatedControls>
    </telerik:AjaxSetting>

这是启动和traget组合框的标记:

<asp:TableRow HorizontalAlign="Center" ID="ProductRow3">
    <asp:TableCell Width="25%" HorizontalAlign="Left" ID="MarketLabelCell">
        <asp:Label ID="lblMarket" runat="server" Text="Market: "></asp:Label>
        <asp:RequiredFieldValidator ID="vldMarket" runat="server" ControlToValidate="rcmbMarket" 
            ErrorMessage="*" ForeColor="Red" SetFocusOnError="true" ValidationGroup="grpMain"></asp:RequiredFieldValidator>
    </asp:TableCell>
    <asp:TableCell Width="25%" HorizontalAlign="Left" ID="MarketDDLCell">
        <telerik:RadComboBox ID="rcmbMarket" runat="server" AllowCustomText="false" DataSourceID="MarketSource" AutoPostBack="true" CausesValidation="false"
            DataTextField="MarketDesc" DataValueField="pkMarketID" AppendDataBoundItems="true" OnSelectedIndexChanged="Market_Check">
            <Items>
                <telerik:RadComboBoxItem Text="" Value="" />
            </Items>
        </telerik:RadComboBox>
        <asp:SqlDataSource ID="MarketSource" runat="server" ConnectionString="<%$ ConnectionStrings:QuoteProdConn %>" SelectCommand="SELECT pkMarketID, MarketDesc FROM Data.Market WHERE Active = 'True' ORDER BY MarketDesc ASC"></asp:SqlDataSource>
    </asp:TableCell>
    <asp:TableCell Width="25%" HorizontalAlign="Left" ID="ApplicationLabelCell">
        <asp:Label ID="lblApplicationField" runat="server" Text="Application Field:"></asp:Label>
        <asp:RequiredFieldValidator ID="vldAppField" runat="server" ControlToValidate="rcmbApplicationField" 
            ErrorMessage="*" ForeColor="Red" SetFocusOnError="true" ValidationGroup="grpMain"></asp:RequiredFieldValidator>
    </asp:TableCell>
    <asp:TableCell Width="25%" HorizontalAlign="Left" ID="ApplicationTextCell">
        <telerik:RadComboBox ID="rcmbApplicationField" runat="server" AllowCustomText="false" DataSourceID="ApplicationFieldSource" ExpandDirection="Down"
            AutoPostBack="true" DataTextField="AppDescription" DataValueField="pkAppFieldID" AppendDataBoundItems="true" CausesValidation="false" MaxHeight="300px">
            <Items>
                <telerik:RadComboBoxItem Text="" Value="" />
            </Items>    
        </telerik:RadComboBox>
        <asp:SqlDataSource ID="ApplicationFieldSource" runat="server" ConnectionString="<%$ ConnectionStrings:QuoteProdConn %>"></asp:SqlDataSource>
    </asp:TableCell>
</asp:TableRow>

以下是市场组合框的选定索引更改时调用的Market_Check子代码背后的代码:

Protected Sub Market_Check(ByVal sender As Object, ByVal e As System.EventArgs)

    Dim tmpItem As New Telerik.Web.UI.RadComboBoxItem("", "")
    ApplicationFieldSource.SelectCommand = "SELECT pkAppFieldID, AppDescription FROM Data.ApplicationField WHERE Active = 'True' AND fkMarketID = " & rcmbMarket.SelectedValue.ToString() & " ORDER BY AppDescription ASC "
    ApplicationFieldSource.DataBind()
    rcmbApplicationField.Items.Clear()
    rcmbApplicationField.Items.Add(tmpItem)
    rcmbApplicationField.DataBind()

End Sub

这一切都非常简单,所以我真的不确定为什么我的这个问题正在发生.任何帮助都将不胜感激.

Answer 1

也尝试使用 Telerik Ajax 更新 ApplicationFieldSource。

不管怎样，这种方法非常棘手，今天你有很多客户端服务器技术比 RadAjaxManager/MS ASP.NET ajax 好得多，例如对简单 Web 服务的简单 jQuery 调用。