Binding an integer value using TemplateBinding shows nothing

Question

I'm trying to bind an integer to a ControlTemplate but shows nothing to me. here is my TextBlock which is a part of my ControlTemplate:

<TextBlock FontSize="14"
           Foreground="#000"
           Text="{TemplateBinding Number}"/>

here is my dependency property which is a part of my CustomControl:

public static readonly DependencyProperty NumberProperty = DependencyProperty.Register(nameof(Number), typeof(int), typeof(MyCustomControl), new PropertyMetadata(0));

public int Number
{
    get => (int)GetValue(NumberProperty);
    set => SetValue(NumberProperty, value);
}

I have tried this also, but it doesn't works too:

 <TextBlock FontSize="14"
            Foreground="#000"
            Text="{Binding Number, RelativeSource={RelativeSource TemplatedParent}, TargetNullValue=''}"/>

if I change it to string it works 😢

Answer 1

You have to use a converter which will convert int to string value. Here's the example of such converter.

public sealed class IntToStringConverter : IValueConverter
{
    public object Convert(object? value, Type targetType, object parameter, string language)
    {
        return ((int)value!).ToString();
    }

    public object ConvertBack(object value, Type targetType, object parameter, string language)
    {
        throw new NotImplementedException();
    }
}

Instead of the TemplatedBinding in the control template you should use such statement.

<TextBlock FontSize="14" Foreground="#000"
           Text="{Binding Number, RelativeSource={RelativeSource Mode=TemplatedParent}, Converter={StaticResource IntToStringConverter}}" />

One more thing. You have to define the converter somewhere in your xaml to be able to use it as a StaticResource.

<c:IntToStringConverter x:Key="IntToStringConverter" />

Update

Converter is not needed to show integer value as text.

 //Working
 Text="{Binding Number, RelativeSource={RelativeSource Mode=TemplatedParent}}"
 
 //Not working    
 Text="{TemplateBinding Number}"