Question

我编码如下所示，并且我在MaskedEditExtender标签中包含了TargetControlID，但我得到的是NullReferenceException：

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Register.aspx.cs" Inherits="Employee_Managment.Register" %>

<%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="ajax" %>
<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <link href="../Styles/bootstrap.min.css" rel="stylesheet" />
</head>
<body>


         <asp:ScriptManager runat="server" ID="ScriptManager1" EnableScriptGlobalization="true"></asp:ScriptManager>
        <%--<asp:TextBox runat="server" ID="autocompletetest"></asp:TextBox>
        <ajax:AutoCompleteExtender runat="server" EnableCaching="false" CompletionInterval="10" MinimumPrefixLength="2" CompletionSetCount="3" TargetControlID="autocompletetest" ServiceMethod="NamePick" FirstRowSelected="false"></ajax:AutoCompleteExtender>
        <asp:Label runat="server" ID="label"></asp:Label>--%>
        <asp:TextBox ID="TextBox3" runat="server" Width="150px"></asp:TextBox>        
        <ajax:MaskedEditExtender ID="MaskedEditExtender2" runat="server" MaskType="None" Mask="9999" TargetControlID="TextBox3">
        </ajax:MaskedEditExtender>
        <%--<ajax:MaskedEditValidator ID="MaskedEditValidator2" runat="server" ControlToValidate="TextBox3" ControlExtender="MaskedEditExtender2" Display="Dynamic" IsValidEmpty="false" InvalidValueMessage="Invalid date!" EmptyValueMessage="The date is not entered">
        </ajax:MaskedEditValidator>   --%>


</body>
</html>

我收到错误，如下所示：

[NullReferenceException: Object reference not set to an instance of an object.]
   AjaxControlToolkit.MaskedEditExtender.OnLoad(EventArgs e) +183
   System.Web.UI.Control.LoadRecursive() +59
   System.Web.UI.Control.LoadRecursive() +131
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2952

请评论解决方案。

Answer 1

请参阅以下代码......这对我有用..

我为maskededit扩展器设置了相同的id并屏蔽了编辑验证器的控制器（这里我的maskededitextender的id是MaskedEditExtender1，我为Maskededitvalidator ControlExtender设置了相同的id）

 <asp:TextBox id="txtStartTime" runat="server" placeholder="HH:mm" OnTextChanged="txtStartTime_TextChanged" AutoPostBack="true" ></asp:TextBox>
                             <ajaxToolkit:MaskedEditExtender ID="MaskedEditExtender1" runat="server"
    AcceptAMPM="false" Mask="99:99" CultureAMPMPlaceholder="" CultureCurrencySymbolPlaceholder=""
    CultureDateFormat="" CultureDatePlaceholder="" CultureDecimalPlaceholder=""
    CultureThousandsPlaceholder="" CultureTimePlaceholder="" Enabled="True"
    MaskType="Time" TargetControlID="txtStartTime" />
                             <ajaxToolkit:MaskedEditValidator ID="MaskedEditValidator4" runat="server"
                 ControlExtender="MaskedEditExtender1"
                 ControlToValidate="txtStartTime"
                 IsValidEmpty="True"
                 EmptyValueMessage="Time is required"
                InvalidValueMessage="Time is invalid"
                 Display="Dynamic"
                 TooltipMessage="Input a time"
                 EmptyValueBlurredText="Invalid Time"
                 InvalidValueBlurredMessage="Invalid Time" />

NullReferenceException：对象引用未设置为ajaxcontroltoolkit中对象的实例？

1 个答案: