如何在 Xamarin.forms 中复制标签的视图框行为？

Question

我想将我的 WPF 应用程序重写为 Xamarin.forms，但我在将标签缩放到最大可用空间时遇到了困难。

在 WPF 我可以简单地做：

<Viewbox Grid.ColumnSpan="2" Grid.RowSpan="3"

         HorizontalAlignment="Center" VerticalAlignment="Center">

    <Label Width="auto" Height="auto"

           HorizontalAlignment="Center" VerticalAlignment="Center"

           Content="ABCD"/>

</Viewbox>

我试过这样的东西，但它只扩展标签的背景而不是文本

<Label Grid.ColumnSpan="2" Grid.RowSpan="3"

       HorizontalOptions="FillAndExpand"

       VerticalOptions="FillAndExpand"

       Text="ABCD"

/>

xamarin.forms 是否提供了与 WPF 视图框内的标签类似的行为？

Answer 1

我想出了这个非常天真的解决方案：XAML：<BoxView x:Name="measureViewBox"&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Grid.RowSpan="3" Grid.ColumnSpan="2"&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;Opacity="0"/><Label x:Name="myLabel"&nbsp;&nbsp; &nbsp; &nbsp; &nbsp;Grid.RowSpan="3" Grid.ColumnSpan="2"&nbsp; &nbsp; &nbsp; &nbsp;HorizontalTextAlignment="Center" VerticalTextAlignment="Center"&nbsp; &nbsp; &nbsp; &nbsp;HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand"&nbsp; &nbsp; &nbsp; &nbsp;Text="ABCD">后面的代码：private void ContentView_SizeChanged(object sender, EventArgs e){&nbsp; &nbsp; double fontSize = measureViewBox.Width;&nbsp; &nbsp; myLabel.FontSize = fontSize;&nbsp; &nbsp; SizeRequest measurement = myLabel.Measure(double.PositiveInfinity, double.PositiveInfinity);&nbsp; &nbsp; while (measurement.Request.Width >= measureViewBox.Width)&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; fontSize -= 2;&nbsp; &nbsp; &nbsp; &nbsp; myLabel.FontSize = fontSize;&nbsp; &nbsp; &nbsp; &nbsp; measurement = myLabel.Measure(double.PositiveInfinity, double.PositiveInfinity);&nbsp; &nbsp; }}当我在 UWP 中调整窗口大小时，它非常滞后，但至少现在，它完成了工作。我将在未来尝试改进这一点，因此任何建议将不胜感激。