Ajax UpdatePanel (10) Validators

Validators:

<asp:UpdatePanel ID="UpdatePanel1" runat="server">

<ContentTemplate>

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>

<asp:RequiredFieldValidator ControlToValidate="TextBox1" ID="RequiredFieldValidator1" runat="server" ErrorMessage="RequiredFieldValidator"></asp:RequiredFieldValidator>

<br />

<asp:Button ID="Button1" runat="server" Text="Button" />

</ContentTemplate>

</asp:UpdatePanel>

In this code, the first time we click Button1 without entering anything, the validator will display the error message which is correct. So we enter some data, click Button1, it will post the data. But now if we click Button1 again without entering anything, the form will not be posted which is right, but the error message cannot be displayed for some reason. So Microsoft provided us with Validators.dll, you can reference that and add the following in the web.config, then it will work.

<system.web>

<pages>

<controls>

<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>

</controls>

<tagMapping>

<add tagType="System.Web.UI.WebControls.CompareValidator" mappedTagType="Microsoft.Web.UI.Compatibility.CompareValidator, Validators"/>

<add tagType="System.Web.UI.WebControls.CustomValidator" mappedTagType="Microsoft.Web.UI.Compatibility.CustomValidator, Validators"/>

<add tagType="System.Web.UI.WebControls.RangeValidator" mappedTagType="Microsoft.Web.UI.Compatibility.RangeValidator, Validators"/>

<add tagType="System.Web.UI.WebControls.RegularExpressionValidator" mappedTagType="Microsoft.Web.UI.Compatibility.RegularExpressionValidator, Validators"/>

<add tagType="System.Web.UI.WebControls.RequiredFieldValidator" mappedTagType="Microsoft.Web.UI.Compatibility.RequiredFieldValidator, Validators"/>

<add tagType="System.Web.UI.WebControls.ValidationSummary" mappedTagType="Microsoft.Web.UI.Compatibility.ValidationSummary, Validators"/>

</tagMapping>

</pages>