Sample Validating Controls in Silverlight

Validating Controls in Silverlight

If ever you have done validation of form controls in ASP.NET or Desktop applications then validating controls in Silverlight will be easy to get to grips with.  Unfortunately there are no controls in Silverlight that perform validation, maybe Microsoft will release some at some point but for now we have a few tips for validating and a simple example Registration Form with basic validation.

<UserControl x:Class="SilverlightApplication1.Page"

    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

    xmlns:liquid="clr-namespace:Liquid;assembly=Liquid"

    Width="400" Height="300">

    <Canvas>

        <Rectangle Width="330" Height="170" RadiusX="7" RadiusY="7" Fill="#44888888" />

        <Rectangle Canvas.Left="2" Canvas.Top="2" Width="326" Height="166" RadiusX="5" RadiusY="5" StrokeThickness="2" Stroke="#888888">

            <Rectangle.Fill>

                <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">

                    <GradientStop Color="#ffdfdfdf" Offset="0.0" />

                    <GradientStop Color="#fff8f8f8" Offset="0.7" />

                    <GradientStop Color="#ffeeeeee" Offset="1.0" />

                </LinearGradientBrush>

            </Rectangle.Fill>

        </Rectangle>

        

        <Rectangle Canvas.Left="5" Canvas.Top="5" Width="320" Height="21" StrokeThickness="0.5" Stroke="#7A8295" RadiusX="3" RadiusY="3">

            <Rectangle.Fill>

                <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">

                    <GradientStop Color="#626C88" Offset="0.0" />

                    <GradientStop Color="#393F4D" Offset="0.5" />

                    <GradientStop Color="#151516" Offset="0.5" />

                    <GradientStop Color="#3C476F" Offset="1.0" />

                </LinearGradientBrush>

            </Rectangle.Fill>

        </Rectangle>

        

        <TextBlock Text="Username:" Canvas.Left="10" Canvas.Top="35" />

        <TextBox x:Name="newUsername" Canvas.Left="120" Canvas.Top="32" Width="200" TabIndex="0" />

        <TextBlock Text="Email:" Canvas.Left="10" Canvas.Top="65" />

        <TextBox x:Name="newEmail" Canvas.Left="120" Canvas.Top="62" Width="200" TabIndex="1" />

        <TextBlock Text="Password:" Canvas.Left="10" Canvas.Top="95" />

        <TextBox x:Name="newPassword" Canvas.Left="120" Canvas.Top="92" Width="200" TabIndex="2" />

        <HyperlinkButton x:Name="registerHelp" Canvas.Left="10" Canvas.Top="146" NavigateUri="help.aspx" Content="Problems Registering?" />

        <TextBlock x:Name="registerStatus" Canvas.Left="10" Canvas.Top="121" Foreground="Red" FontSize="10" FontWeight="Bold" />

        <Button Canvas.Left="200" Canvas.Top="133" Width="50" Content="Cancel" Click="RegisterCancel_Click" />

        <Button x:Name="registerRegister" Canvas.Left="260" Canvas.Top="133" Width="60" Content="Register" Click="Register_Click" />

    </Canvas>

</UserControl>

code behind

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net;

using System.Text;

using System.Text.RegularExpressions;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;

using System.Windows.Media.Animation;

using System.Windows.Shapes;

namespace SilverlightApplication1

{

    public partial class Page : UserControl

    {

        public Page()

        {

            InitializeComponent();

        }

        private void RegisterCancel_Click(object sender, RoutedEventArgs e)

        {

            // Registration has been cancelled. Handle this here

        }

        private void Register_Click(object sender, RoutedEventArgs e)

        {

            // Clear the status text

            registerStatus.Text = "";

            if (newPassword.Text.Length == 0)

            {

                // No password entered

                registerStatus.Text = "Enter a password.";

                newPassword.Focus();

            }

            if (newEmail.Text.Length == 0)

            {

                // No email address entered

                registerStatus.Text = "Enter an email.";

                newEmail.Focus();

            }

            else if (!Regex.IsMatch(newEmail.Text, @"^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$"))

            {

                // An invalid email format was entered

                registerStatus.Text = "Enter a valid email.";

                newEmail.Select(0, newEmail.Text.Length);

                newEmail.Focus();

            }

            if (newUsername.Text.Length == 0)

            {

                // No username was entered

                registerStatus.Text = "Enter a username.";

                newUsername.Focus();

            }

            // Return if the status text is not empty

            if (registerStatus.Text.Length > 0)

            {

                return;

            }

            // All done, the 3 fields have been validated

            // Do your registration processing here....

        }

    }

}