asp.net – 使CustomValidator与ValidationSummary消息框一起工作的优雅方式

我以前遇到这个问题，但从来没有解决过。我有一个表单与几个验证器和一个CustomValidator。

<asp:Label ID="lblMemberNum" runat="server" Text="Membership #:" CssClass="LabelMedium"  ></asp:Label>
<asp:TextBox ID="txtMemberNum" runat="server" CssClass="TextBox" ></asp:TextBox>
<asp:requiredFieldValidator ID="rfvMemberNum" SetFocusOnError="True" runat="server"
    ControlTovalidate="txtMemberNum" ErrorMessage="[ Membership # ] is required"
    CssClass="ValidationMessage" display="Dynamic" >*</asp:requiredFieldValidator>
<asp:RegularExpressionValidator ID="revMemberNum"  display="Dynamic" runat="server" 
    ControlTovalidate="txtMemberNum" CssClass="ValidationMessage" 
    ErrorMessage="[ Membership # ] can only contain letters" 
    ValidationExpression="^([a-zA-Z\d]+)$" >*</asp:RegularExpressionValidator>
<asp:CustomValidator ID="cvMemberNum" runat="server" 
    CssClass="ValidationMessage" display="Dynamic"
    ControlTovalidate="txtMemberNum" ValidateEmptyText="false"
    OnServerValidate="cvMemberNum_Validate" 
    ErrorMessage="This membership number is already registered">*</asp:CustomValidator>

<asp:ValidationSummary ID="ValidationSummary1" runat="server" 
    CssClass="ValidationMessage" 
    ShowMessageBox="True" ShowSummary="False" />

在服务器端：

protected void cvMemberNum_Validate(object source,ServerValidateEventArgs args)
{
    try
    {
        args.IsValid  = (!CampaignRegistration.IsMemberRegistered(args.Value));
    }
    catch
    {
        args.IsValid = false;
    }
}

我的问题是：ValidationSummary从未显示CustomValidator的消息。这个问题在几个地方被问到，但我没有看到令人满意的答案。

解决方法

尝试在所有验证器和ValidationSummary之间使用ValidationGroup属性。

编辑：另一种可能是服务器验证码

args.IsValid = (!CampaignRegistration.IsMemberRegistered(args.Value));

如果CampaignRegistration.IsMemberRegistered(args.Value)返回false，“！”使它成真，因此使其有效。我想你应该摆脱“！”如下：

args.IsValid = CampaignRegistration.IsMemberRegistered(args.Value);

更新：为了使ValidationSummary在消息框中显示您的自定义验证器消息，您需要具有ClientValidationFunction代码。如果您只需显示摘要而不显示弹出窗口，则不需要。

<asp:CustomValidator ID="cvMemberNum" runat="server" 
    CssClass="ValidationMessage" display="Dynamic"
    ControlTovalidate="txtMemberNum" ValidateEmptyText="false"
    OnServerValidate="cvMemberNum_Validate"
    ClientValidationFunction = "ClientValidate"  
    ErrorMessage="This membership number is already registered">*</asp:CustomValidator>
   //JavaScript Code.
   function ClientValidate(source,args)
   {         
      args.IsValid = false; //you need to add validation logic here
   }

更多：如果您不想做ClientSide验证，请尝试此技巧来显示警报。对您的CustomValidator ServerValidate方法进行此更改：

protected void cvMemberNum_Validate(object source,ServerValidateEventArgs args)
{
    bool isValid = true;
    try
    {
        isValid  = (!CampaignRegistration.IsMemberRegistered(args.Value));
    }
    catch
    {
        isValid = false;
    }
    args.IsValid = isValid;

    if(!isValid)
    {
       if(!Page.IsClientScriptBlockRegistered("CustomValidation")) 
         Page.RegisterClientScriptBlock("CustomValidation","<script>alert('This membership number is already registered');</script>"); 

    }

}

原文地址：https://www.jb51.cc/aspnet/252902.html