通过媒体查询来实现|通过媒体查询来实现 WPF 响应式设计

【通过媒体查询来实现|通过媒体查询来实现 WPF 响应式设计】WPF 客户端经常需要运行在各种不同大小屏幕下,为了显示友好,所以开发的时候都需要考虑响应式设计。
布局往往通过指定比例,而不直接指定准确的大小来实现响应式布局(如 Width="3*" ),但是具体控件的大小(如 Thickness、CornerRadius)就没有开箱即用的响应式功能了,用 viewbox 来包装,比例就跟设计稿不一样了,看起来很怪。
嗐,所以又只能自己开发了!
实现目标

  • 实现类似 css @media 媒体查询类似的功能。
  • 设计稿都是 1920 × 1080 实现的,在 3840 × 2160 下,应该将所有控件的大小,边框放大两倍。
  • 要考虑用户在系统下设定的缩放比例。
  • 同事用起来要舒服,要支持热重载。
实现逻辑 根据屏幕大小和屏幕缩放比例来计算缩放系数。
  • 屏幕的 api 当然是白嫖别人写的库啦,我这里用的是 WpfScreenHelper。
public static class AppExtension { private static double? _factor; /// /// 获取当前应用的缩放系数 /// 如果 4K 屏幕,需要放大 2 倍 /// /// /// public static double GetFactor(this Application app) { if (_factor is not null) return _factor.Value; var screen = app.MainWindow?.GetScreen() ?? throw new ArgumentNullException(nameof(app.MainWindow)); _factor = screen.PixelBounds switch { { Width: >= 3840, Height: >= 2160 } => screen.ScaleFactor / 2, _ => screen.ScaleFactor }; Debug.WriteLine($"屏幕大小: {screen.PixelBounds.Width} × {screen.PixelBounds.Height}"); Debug.WriteLine($"屏幕缩放: {screen.ScaleFactor * 100}%"); return _factor.Value; }/// /// 根据屏幕大小和缩放系统,转换不同的数据类型 /// /// /// /// /// public static object ConvertForScreen(this Application app, object o) => o switch { double d => app.ConvertDoubleForScreen(d), Thickness t => app.ConvertThicknessForScreen(t), CornerRadius t => app.ConvertCornerRadiusForScreen(t), _ => throw new NotSupportedException("不支持的转换类型") }; public static double ConvertDoubleForScreen(this Application app, double value) { var factor = app.GetFactor(); return value / factor; }public static Thickness ConvertThicknessForScreen(this Application app, Thickness value) { var factor = app.GetFactor(); return new Thickness(value.Left / factor, value.Top / factor, value.Right / factor, value.Bottom / factor); }public static CornerRadius ConvertCornerRadiusForScreen(this Application app, CornerRadius value) { var factor = app.GetFactor(); return new CornerRadius(value.TopLeft / factor, value.TopRight / factor, value.BottomRight / factor, value.BottomLeft / factor); }/// /// 获取当前窗体所在的屏幕 /// /// 当前窗体 /// 窗体所在的屏幕 public static Screen GetScreen(this Window window) { var intPtr = new WindowInteropHelper(window).Handle; //获取当前窗口的句柄 return Screen.FromHandle(intPtr); //获取当前屏幕 } }

自定义 xaml 标记
  • 适配 Setter 上赋值和直接在控件上赋值的场景。
  • 通过各种转换器来转换值。
public class ResponsiveSizeExtension : MarkupExtension { private static readonly Lazy _lazyDouble = new(); private static readonly Lazy _lazyThickness = new(); private static readonly Lazy _lazyCornerRadius = new(); private DoubleConverter _doubleConverter => _lazyDouble.Value; private ThicknessConverter _thickConvert => _lazyThickness.Value; private CornerRadiusConverter _cornerRadiusConvert => _lazyCornerRadius.Value; [ConstructorArgument("value")] public object Value { get; set; }public ResponsiveSizeExtension(object value) { if (value is string s && string.IsNullOrWhiteSpace(s)) value = "https://www.it610.com/article/0"; Value = https://www.it610.com/article/value; }public override object ProvideValue(IServiceProvider serviceProvider) { var target = (IProvideValueTarget)serviceProvider; var type = target switch { { TargetObject: Setter setter } => setter.Property.PropertyType, { TargetProperty: DependencyProperty dp } => dp.PropertyType, _ => throw new NotSupportedException($"不是 Setter 对象或者依赖属性") }; TypeConverter converter = type switch { not null when type == typeof(double) => _doubleConverter, not null when type == typeof(Thickness) => _thickConvert, not null when type == typeof(CornerRadius) => _cornerRadiusConvert, _ => throw new NotSupportedException($"{type} 类型不支持") }; var originValue = https://www.it610.com/article/converter.ConvertFrom(Value) ?? throw new ArgumentException(nameof(Value)); var newValue = Application.Current.ConvertForScreen(originValue); PrintLog(originValue, newValue); return newValue; }private void PrintLog(object originValue, object newValue) => Debug.WriteLine($"originValue: {originValue}, newValue: {newValue}, factor: {Application.Current.GetFactor()}"); }

使用

效果
屏幕大小: 1920 × 1080 屏幕缩放: 100% originValue: 12,12,12,12, newValue: 12,12,12,12, factor: 1 originValue: 200, newValue: 200, factor: 1 originValue: 16, newValue: 16, factor: 1屏幕大小: 3840 × 2160 屏幕缩放: 100% originValue: 12,12,12,12, newValue: 24,24,24,24, factor: 0.5 originValue: 200, newValue: 400, factor: 0.5 originValue: 16, newValue: 32, factor: 0.5屏幕大小: 3840 × 2160 屏幕缩放: 150% originValue: 12,12,12,12, newValue: 16,16,16,16, factor: 0.75 originValue: 200, newValue: 266.6666666666667, factor: 0.75 originValue: 16, newValue: 21.333333333333332, factor: 0.75

最后
响应式设计在 WPF 应该还有很多实现方法,有方便的思路请留言教教我! 用模式匹配写逻辑是真舒服,建议大家都试试,代码简单又明了。 觉得对你有帮助点个推荐或者留言交流一下呗! 源码 https://github.com/yijidao/blog/tree/master/WPF/Responsive

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