在xaml上将负值显示为正值

public class MyData
{
    public int Value { get; set; }
}

using System;
using System.Globalization;
using System.Windows.Data;

public class NegativeToPositiveConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        if (value is int intValue && intValue < 0)
        {
            return -intValue;
        }
        return value;
    }

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

<Window x:Class="YourNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:YourNamespace"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <local:NegativeToPositiveConverter x:Key="NegativeToPositiveConverter"/>
    </Window.Resources>
    <Grid>
        <TextBlock Text="{Binding Value, Converter={StaticResource NegativeToPositiveConverter}}" FontSize="24" HorizontalAlignment="Center" VerticalAlignment="Center"/>
    </Grid>
</Window>

using System.Windows;

namespace YourNamespace
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            DataContext = new MyData { Value = -10 };
        }
    }
}