C# 将父控件的子高度或宽度设置为与“相同”；匹配“家长”；在android中

我有一个网页，其中包括一个网格和网格内有一个地图。但我无法将地图的大小设置为网格大小。虽然我可以在代码中将其设置为

MyMap.Height = LayoutRoot.ActualHeight;
MyMap.Width = LayoutRoot.ActualWidth;

但是如何在xaml中设置它呢

<phone:PhoneApplicationPage
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    xmlns:maps="clr-namespace:Microsoft.Phone.Maps.Controls;assembly=Microsoft.Phone.Maps"
    x:Class="MapSample.MainPage"
    mc:Ignorable="d"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <Grid x:Name="LayoutRoot" Background="Red">
        <maps:Map x:Name="MyMap" HorizontalAlignment="Left" VerticalAlignment="Top" Center="47.6097, -122.3331" ZoomLevel="10"/>
    </Grid>

</phone:PhoneApplicationPage>

---

您应该将地图控件的

水平对齐

和

垂直对齐

设置为

拉伸

<maps:Map x:Name="MyMap"
          HorizontalAlignment="Stretch"
          VerticalAlignment="Stretch"
          Center="47.6097, -122.3331"
          ZoomLevel="10" />