.NET Mobile Input Validation

From http://www.w3schools.com (Copyright Refsnes Data)

# .NET Mobile Input Validation

Validation Controls are used to validate the data entered by a user.

## Validation Controls

Validation controls are used to validate the data entered by a user.

Validation controls allow you to validate an input control (like a TextBox), and display a message when validation fails.

Each validation control performs a specific type of validation (like validating against a specific value or a range of values).

By default, page validation is performed when a command control is clicked. You can prevent validation when a control is clicked by setting the CausesValidation property to false.

## Validating Input

This page has two forms:

    <%@ Page
    Inherits=
    "System.Web.UI.MobileControls.MobilePage"%>
    <%@ Register
    TagPrefix="Mobile"
    Namespace="System.Web.UI.MobileControls"
    Assembly="System.Web.Mobile" %>

    <script runat="server">

    Sub Page2(Sender as Object,E as EventArgs)
    If Page.IsValid Then
      ActiveForm=f2
      text2.Text="You are " & age.text & " years old"
    end if
    End Sub

    </script>

    <Mobile:Form id="f1" runat="server">

    <Mobile:CompareValidator runat="server"
      ControlToValidate="age"
      Type="Integer"
      ValueToCompare="18"
      Operator="GreaterThanEqual">
    You must be at least 18
    </Mobile:CompareValidator>

    <Mobile:Label runat="server">Age?</Mobile:Label>
    <Mobile:TextBox id="age" runat="server" />
    <Mobile:Command OnClick="Page2" runat="server">
    Submit</Mobile:Command>
    </Mobile:Form>

    <Mobile:Form id="f2" runat="server">
    <Mobile:Label id="text2" runat="server" />
    </Mobile:Form>

The first form has a label with the text "Age?", an input box to input the age, and a submit button.

The second page is activated by the submit button on the first page, and displays a response.

If the input validates as error, an error message is displayed.

When the application runs on a mobile device, the two pages will display like this:

Form 1

Age?

Form 2

You are 21 years old

## The ValidationSummary Control

The previous example used a CompareValidator control to validate an input field. The field to validate was defined by the attribute ContolToValidate.

You can also use a ValidationSummary control with the attribute FormToValidate, to validate all the input of a form.

This way you can display a summary of errors instead of one error at the time.

## Validation Controls Reference

Name | Function
--- | ---
CompareValidator | Compares two values
CustomValidator | Provides custom validation
RangeValidator | Validates a range
RegularExpressionValidator | Validates an expression
RequiredFieldValidator | Validates required data
ValidationSummary | Displays a validation summary

For a full control reference, including properties methods, events, and more examples, please refer to the "Mobile Reference" page.

From http://www.w3schools.com (Copyright Refsnes Data)