您可以像这样创建转换器：

• • 双倍厚度转换器. cs**

using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Data;
using System;

namespace Converters;

public class DoubleToThicknessConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, string language)
    {
        if (value is double doubleValue)
        {
            List<int>? coefficients = (parameter as string)?
                .Split(',')
                .Select(x => int.Parse(x))
                .ToList<int>();

            if (coefficients?.Count is not 4)
            {
                coefficients = new() { 1, 1, 1, 1 };
            }

            return new Thickness(
                left: doubleValue * coefficients[0],
                top: doubleValue * coefficients[1],
                right: doubleValue * coefficients[2],
                bottom: doubleValue * coefficients[3]);
        }

        throw new ArgumentException();
    }

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

并像这样使用它：

• • 主页. xaml**

<Page
    x:Class="Converters.MainPage"
    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:local="using:Converters"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}"
    mc:Ignorable="d">
    
    <Page.Resources>
        <local:DoubleToThicknessConverter x:Key="DoubleToThicknessConverter" />
    </Page.Resources>

    <Border
        BorderBrush="SkyBlue"
        BorderThickness="{x:Bind ThicknessSlider.Value, Mode=OneWay, Converter={StaticResource DoubleToThicknessConverter}, ConverterParameter='0,3,1,3'}">
        <Slider x:Name="ThicknessSlider" />
    </Border>
    
</Page>

• • 更新**

添加任意系数作为转换器参数。现在你可以设置一个系数为左，上，右和底部厚度。例如，你可以设置'0，0，0，1'如果你只想使用底部厚度或设置'1，2，1，2'加倍顶部和底部的厚度。