RequiredFieldValidator Class
Provides control capability to validate whether the value of the associated input control is different from its initial value.
public class System.Web.UI.MobileControls.RequiredFieldValidator :
System.Web.UI.MobileControls.BaseValidator
Remarks
This class behaves identically to the ASP.NET System.Web.UI.WebControls.RequiredFieldValidator control.
By default, Command controls on a form raise validator controls on the form to perform validation when the form is submitted to the server. To disable automatic validation, set the CausesValidation property on the Command controls to false.
Example
The following code example requires a user to enter a number from 1 to 23. It uses both the RangeValidator Control control and the RequiredFieldValidator control to validate user entries.
<%@ Page Inherits=
"System.Web.UI.MobileControls.MobilePage" Language="VB" %>
<%@ Register TagPrefix="mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>
<script language="vb" runat="server">
Sub Page_Load(sender As Object, e As EventArgs)
If Not IsPostBack Then
Valid1.ControlToValidate = "TextBox1"
Valid1.Type = ValidationDataType.Integer
Valid1.MaximumValue = "23"
Valid1.MinimumValue = "1"
End If
End Sub
Protected Sub Submit_Click(sender As Object, e As EventArgs)
If Page.IsValid Then
ActiveForm = Form2
End If
End Sub
</script>
<mobile:Form id="Form1" runat="server">
<mobile:Label runat="server">
Please enter an integer from 1 through 23
</mobile:Label>
<mobile:TextBox id="TextBox1" runat="server"/>
<mobile:RangeValidator id="Valid1" runat="server">
Invalid number
</mobile:RangeValidator>
<mobile:RequiredFieldValidator ControlToValidate="TextBox1"
runat="server">
A number is required
</mobile:RequiredFieldValidator>
<mobile:Command runat="server" OnClick="Submit_Click">
Submit
</mobile:Command>
</mobile:Form>
<mobile:Form id="Form2" runat="server">
<mobile:Label runat="server">Number is submitted</mobile:Label>
</mobile:Form>
[C#]
<%@ Page Inherits=
"System.Web.UI.MobileControls.MobilePage" Language="C#" %>
<%@ Register TagPrefix="mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>
<script language="c#" runat="server">
void Page_Load(Object sender, EventArgs e)
{
if (!IsPostBack)
{
Valid1.ControlToValidate = "TextBox1";
Valid1.Type = ValidationDataType.Integer;
Valid1.MaximumValue = "23";
Valid1.MinimumValue = "1";
}
}
protected void Submit_Click(Object sender, EventArgs e)
{
if (Page.IsValid)
{
ActiveForm = Form2;
}
}
</script>
<mobile:Form id="Form1" runat="server">
<mobile:Label runat="server">
Please enter an integer from 1 through 23
</mobile:Label>
<mobile:TextBox id="TextBox1" runat="server"/>
<mobile:RangeValidator id="Valid1" runat="server">
Invalid number
</mobile:RangeValidator>
<mobile:RequiredFieldValidator ControlToValidate="TextBox1"
runat="server">
A number is required
</mobile:RequiredFieldValidator>
<mobile:Command runat="server" OnClick="Submit_Click">
Submit
</mobile:Command>
</mobile:Form>
<mobile:Form id="Form2" runat="server">
<mobile:Label runat="server">Number is submitted</mobile:Label>
</mobile:Form>
Requirements
Namespace: System.Web.UI.MobileControls
Assembly: System.Web.Mobile
See Also
RequiredFieldValidator Control | BaseValidator Class | CompareValidator Class | CustomValidator Class | RangeValidator Class | RegularExpressionValidator Class | ValidationSummary Class