Question

I need to write simple page with 3 textBox
1. textBox1 ==> contain number only
2. textBox2 ==> contain Email address
3. textBox3 ==> contain user name only

I want to make some validation check on each textBox – and in case there is some problem with the user input – to make the textBox border to be in red color and show right message about the error.

How can i do it ?

Thanks for any help.

Answer 1

Here is a sample: SimpleValidation

It makes use of DataAnnotations so you can set your validation in the attribute.

Here is the code:

MainPage.cs

public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();
            DataContext = new DataModel();
        }
    }

MainPage.xaml

<UserControl x:Class="Org.Vanderbiest.SimpleValidation.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <Grid.RowDefinitions>
            <RowDefinition Height="30" />
            <RowDefinition Height="30" />
            <RowDefinition Height="30" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="150" />
            <ColumnDefinition Width="150" />
        </Grid.ColumnDefinitions>

        <TextBlock Grid.Row="0" Grid.Column="0" Text="Number Textbox" />
        <TextBlock Grid.Row="1" Grid.Column="0" Text="Email Textbox" />
        <TextBlock Grid.Row="2" Grid.Column="0" Text="Username Textbox" />

        <TextBox Grid.Row="0" Grid.Column="1" Text="{Binding Number,Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True}"/>
        <TextBox Grid.Row="1" Grid.Column="1" Text="{Binding Email,Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True}"/>
        <TextBox Grid.Row="2" Grid.Column="1" Text="{Binding Username,Mode=TwoWay, ValidatesOnExceptions=True, NotifyOnValidationError=True}"/>
    </Grid>
</UserControl>

DataModel.cs:

public class DataModel : INotifyPropertyChanged
    {
        private string _number;
        [Range(0 ,1000, ErrorMessage = "Number must be between 0 and 1000")]
        public string Number
        {
            get { return _number; }
            set {
                Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = "Number" });
                _number = value;
                RaisePropertyChanged("Number");
            }
        }


        private string _email;

        [RegularExpression("[A-Z0-9._%-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}", ErrorMessage = "Invalid Email")]
        public string Email
        {
            get { return _email; }
            set
            {
                Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = "Email" });
                _email = value;
                RaisePropertyChanged("Email");
            }
        }

        private string _username;

        [Required(ErrorMessage = "User Name is Required")]
        [StringLength(12, MinimumLength = 6, ErrorMessage = "User Name must be in between 6 to 12 Characters")]
        public string Username
        {
            get { return _username; }
            set
            {
                Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = "UserName" });
                _username = value;
                RaisePropertyChanged("Username");
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        public void RaisePropertyChanged(string propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
        }


    }

HTH