WPF IValueConverter doesn't work. How Can I Fix it?

Question

Hello,

I'm posting a question because of something make me stuck in writing WPF app.

I want to change foreground of TextBox when value is over the baseline.

so, I wrote a code about value converter as follows:

using System.Text;
using System.Windows.Data;
using System.Windows.Media;

namespace WpfApp1.Converters
{
public class AgeToForegroundConverter : IValueConverter
{
// Called when converting the Age to a Foreground brush
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
// Only convert to brushes...
if (targetType != typeof(Brush)) { return null; }

        // DANGER! After 25, it's all down hill...
        int age = int.Parse(value.ToString());
        return age > 25 ? Brushes.Red : Brushes.Black;
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        // should not be called in our example
        throw new NotImplementedException();
    }
}

public class Base16Converter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        // Convert to base 16
        return ((int)value).ToString("x");
    }

    public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        // Convert from base 16
        return int.Parse((string)value, System.Globalization.NumberStyles.HexNumber);
    }
}

}

And, I bound these converters to Textboxes as follows:

x:Class="WpfApp1.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:WpfApp1.Converters"
Title="MainWindow"
Width="200"
Height="135"
mc:Ignorable="d">

Grid.Row="0"
Grid.Column="0"
Margin="5"
VerticalAlignment="Center">
Name:

Name="nameTextBox"
Text="{Binding Path=Name}"
Grid.Row="0"
Grid.Column="1"
Margin="5" />
Grid.Row="1"
Grid.Column="0"
Margin="5"
VerticalAlignment="Center">
Age:

Name="ageTextBox"
Foreground="{Binding Path=Age, Converter={ StaticResource ageConverter}}"
Text="{Binding Path=Age, Converter={StaticResource base16Converter}}"
Grid.Row="1"
Grid.Column="1"
Margin="5" />

I didn't get any error messages from above code. but these codes didn't work when I run the app.
if someone help me to fix this, I would be very appreciated.

thanks,

seihyung

Accepted Answer

What does your IValueConverter doesn't work refer to? Did the data binding fail or the converter fail?

Data binding fail: Please add below class and this.DataContext = new MyModel(); in xaml.cs:

 public class MyModel : INotifyPropertyChanged  
    {  
        public MyModel()  
        {  
             
        }  
        private int age;  
        private string name;  
  
        public event PropertyChangedEventHandler PropertyChanged;  
  
        public int Age  
        {  
            get { return age; }  
            set  
            {  
                age = value;  
                if (this.PropertyChanged != null)  
                {  
                    this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("age"));  
                }  
            }  
        }  
        public string Name  
        {  
            get { return name; }  
            set  
            {  
                name = value;  
                if (this.PropertyChanged != null)  
                {  
                    this.PropertyChanged.Invoke(this, new PropertyChangedEventArgs("name"));  
                }  
            }  
        }  
    }

Converter fail: I test your converters, but the second converter in ageTextBox doesn't work. I add triggers in your xam as below:

Please point out if I misunderstand your question.

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WPF IValueConverter doesn't work. How Can I Fix it?

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