文本框的自定义验证

Question

我有一个包含大约 30 个文本框的表格。 每行有 2 个文本框，它们具有相同的前缀但不同的后缀，例如 txtAvg From 和 txtAvg To。 我需要遍历表格并对文本框执行自定义验证：

1. 只有整数
2. 如果 to 和 from 文本框都填写了，我必须检查 from 文本框中的值是否小于 from 值。
3. 在每个文本框中输入的范围是 1-100

我稍后可能需要更多验证。此外，如果填写了 to 文本框，则不需要 from，反之亦然。不需要文本框。

我需要进行服务器端验证。 我应该添加自定义验证控件吗？如果是，那么对于每个文本框？ 我是否设置controltovalidate？ 单击提交按钮时，我需要在每行旁边显示正确的错误。显然，如果页面无效，则不要做任何进一步的事情。

我不想添加不同的验证控件。只有一个自定义验证器。 我还需要动态执行此操作，当用户单击提交按钮时，我希望进行验证并在错误行旁边显示 (*)，并在验证摘要中显示完整的错误消息。

我尝试添加控件，但单击按钮时它没有被触发。

Private Sub AddCustomValidation(ByVal container As Control)
    Dim custom As CustomValidator

    Dim vldtxt As TextBox

    For Each ctrl In container.Controls
        If TypeOf ctrl Is TextBox Then
            vldtxt = CType(ctrl, TextBox)
            custom = New CustomValidator
            custom.Text = "To field must be bigger than from field"
            custom.ControlToValidate = vldtxt.ID
            AddHandler custom.ServerValidate, AddressOf CustomValidation

            '  custom.ServerValidate += New System.Web.UI.WebControls.ServerValidateEventHandler(customvalidation)

            Me.form1.Controls.Add(custom)
        Else
            AddCustomValidation(ctrl)
        End If
    Next
End Sub

Protected Sub CustomValidation(ByVal source As System.Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs)

    Dim vldtxt As TextBox
    Dim othertxt As TextBox
    Dim othertxtid As String
    Dim txtid As String
    Dim lower As String
    Dim higher As String

    For Each ctrl As Control In tbl1.Controls
        vldtxt = TryCast(ctrl, TextBox)
        othertxt = TryCast(ctrl, TextBox)

        If vldtxt IsNot Nothing Then

            txtid = ctrl.ID
            ''check if to is not empty and if not empty then check that that to value is higher
            ''than from value
            If ((txtid.ToLower.EndsWith("to")) And (vldtxt.Text <> "")) Then

                higher = (vldtxt.Text)
                othertxtid = vldtxt.ID.Replace("To", "From")
                othertxt = Page.FindControl(othertxtid)
                othertxt.ID = othertxtid
                lower = (othertxt.Text)
                If lower = String.Empty Or higher = String.Empty Then
                    args.IsValid = True
                End If

                If Int32.Parse(lower) >= Int32.Parse(higher) Then
                    args.IsValid = False
                End If
            Else
                args.IsValid = True
            End If



        End If
    Next
End Sub

布局是这样的：

<table id="tbl1" runat="server" cellpadding="0" cellspacing="3">
    <tr>
        <td>From price</td>
        <td>
            <asp:TextBox runat="server" ID="txtPriceFrom">
        </td>
        <td>To price</td>
        <td>
            <asp:TextBox runat="server" ID="txtPriceTo">
        </td>
        <td>From yield</td>
        <td>
            <asp:TextBox runat="server" ID="txtYieldFrom">
        </td>
        <td>To yield</td>
        <td>
            <asp:TextBox runat="server" ID="txtYieldTo">
        </td>
    </tr>
</table>

Answer 1

您可以使用 ASP.NET 验证控件：

1. RegularExpressionValidator

2. CustomValidator（在code behind中验证）

3. RangeValidator

   <asp:CustomValidator ID="CustomValidator1" runat="server" 
       ErrorMessage="if both to and from textboxes are filled in I have to check that the value in from textbox is smaller than the from value" >
   </asp:CustomValidator>
   
   <table>
       <tr>
           <td>From price</td>
           <td>
               <asp:TextBox runat="server" ID="txtPriceFrom"></asp:TextBox>
   
               <asp:RegularExpressionValidator runat="server" 
                   ControlToValidate="txtPriceFrom"
                   ErrorMessage="Please Enter Only Numbers" 
                   ForeColor="Red" 
                   ValidationExpression="^\d+$">
               </asp:RegularExpressionValidator>
   
               <asp:RangeValidator runat="server" 
                   ControlToValidate="txtPriceFrom"
                   ErrorMessage="Range entered in each textbox is 1-100"
                   MaximumValue="100" MinimumValue="1">
               </asp:RangeValidator>
           </td>
           <td>To price</td>
           <td>
               <asp:TextBox runat="server" ID="txtPriceTo"></asp:TextBox>
               ...
           </td>
           <td>From yield</td>
           <td>
               <asp:TextBox runat="server" ID="txtYieldFrom"></asp:TextBox>
               ...
           </td>
           <td>To yield</td>
           <td>
               <asp:TextBox runat="server" ID="txtYieldTo"></asp:TextBox>
               ...
           </td>
       </tr>
   </table>