Validierung - 2. Teil

 

 

MainWindow.xaml.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace KONVERTRIERUNG
{
/// <summary>
/// Interaktionslogik für MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
private string _message;
public string Message
{
get { return _message; }
set
{

_message = value;
}
}

public MainWindow()
{
InitializeComponent();

DataContext = this;
}
}
}

 


MainWindow.xaml:

<Window x:Class="KONVERTRIERUNG.MainWindow"
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"
xmlns:local="clr-namespace:KONVERTRIERUNG"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<TextBox Width="250" Height="30" x:Name="tbMessage">
<TextBox.Text>
<Binding Path="Message" UpdateSourceTrigger="PropertyChanged">
<Binding.ValidationRules>
<local:NoEmptyStringValidator />
</Binding.ValidationRules>
</Binding>
</TextBox.Text>
</TextBox>
<TextBlock Text="{Binding ElementName=tbMessage, Path=(Validation.Errors)[0].ErrorContent}" x:Name="textBlock" HorizontalAlignment="Left" Margin="134,124,0,0" VerticalAlignment="Top" Width="250"/>
</Grid>
</Window>

 


NoEmptyStringValidator.cs:

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;

namespace KONVERTRIERUNG
{
public class NoEmptyStringValidator : ValidationRule
{
public override ValidationResult Validate(object value, CultureInfo cultureInfo)
{
string valueFromSource = value.ToString();

if (string.IsNullOrEmpty(valueFromSource))
{
return new ValidationResult(false, "Bitte hier etwas eintragen");
}
return new ValidationResult(true, null);
}
}
}

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