UWP颜色前景ListView条件

Question

I would like to know if it's possible to make a condition on a textblock in a ListView. I explain :

I have a models which contains some data and there is an "amount" in this models. If the amount is negative I would like to put the foreground in red, and if it's positive I would like to put the foreground in green.

 <TextBlock RelativePanel.AlignRightWithPanel="True"
                               Foreground="Red"
                               FontWeight="Bold">
                        <Run Text="{Binding Amount}" />
                        <Run Text="€" />
 </TextBlock>

This is the textblock, he is in a ListView.ItemTemplate.

Regards,

Anthony

Answer 1

You should use a converter. Create a class (eg AmountColorConverter ) that derives from IValueConverter .

public object Convert(object value, ...)
{
    var val = (double)value;
    return val >= 0
        ? Colors.Green
        : Colors.Red;
}

Once implemented, create an instance of the converter in XAML and reference it in the binding:

<converter:AmountColorConverter x:Key="AmountColorConverter"/>
<TextBlock RelativePanel.AlignRightWithPanel="True"
           Foreground="{Binding Amount, Converter={StaticResource AmountColorConverter}}"
           FontWeight="Bold">
    <Run Text="{Binding Amount}" />
    <Run Text="€" />
</TextBlock>

Answer 2

I've already try it. He my xaml code :

<TextBlock HorizontalAlignment="Right"
           Grid.Column="2"
           Grid.Row="0"
           Foreground="{Binding Amount, Mode=TwoWay, Converter={StaticResource ForegroundColorAmount}}"
           FontWeight="Medium">
               <Run Text="{Binding Amount}" Foreground="{Binding Amount, Mode=TwoWay, Converter={StaticResource ForegroundColorAmount}}" />
               <Run Text="€" />

And of course I used the using :

xmlns:converters="using:Sample.Converters"

And here my converter class :

    public class ForegroundColorAmount : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, string language)
    {
        var val = (double)value;
        if (val >= 0)
        {
            return Colors.Green;
        }
        else
        {
            return Colors.Red;
        }
    }

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

Thank's.

Anthony