在Windows Phone中以横向模式进行协调

Question

这是我在横向模式下的应用程序（以及网格内的两个边框，名为'LayoutRoot'）。

1）我试图以这种方式接收border1的坐标：

    GeneralTransform generalTransform = border1.TransformToVisual(LayoutRoot);
    Point point = generalTransform.Transform(new Point(0, 0));

它返回我预期的点坐标： X = 0，Y = 380

2）现在我试图通过这些坐标接收相同的border1：

var controls = VisualTreeHelper.FindElementsInHostCoordinates(
                    point, LayoutRoot).ToArray();

我突然收到了border2！似乎FindElementsInHostCoordinates认为它处于纵向模式。如何正确地以横向模式通过坐标接收控件？

Answer 1

似乎FindElementsInHostCoordinates不考虑横向模式或SystemTray的存在。它只适用于使用带有SystemTray.IsVisible =“False”的Portrait坐标时。

查看Alan Mendelevich的博文，了解更多详情：

http://devblog.ailon.org/devblog/post/2011/04/03/Obstruction-Detection-in-Silverlight-for-Windows-Phone.aspx

如果可见，则需要为SystemTray维度执行与此+帐户类似的操作。

示例代码：

using System.Linq;
using System.Windows;
using System.Windows.Media;
using Microsoft.Phone.Controls;
using Microsoft.Phone.Shell;

namespace PhoneApp4
{
    public partial class MainPage : PhoneApplicationPage
    {
        // Constructor
        public MainPage()
        {
            InitializeComponent();
            this.Loaded += new RoutedEventHandler(MainPage_Loaded);
        }

        void MainPage_Loaded(object sender, RoutedEventArgs e)
        {
            GeneralTransform generalTransform = border1.TransformToVisual(LayoutRoot);
            Point point = generalTransform.Transform(new Point(1, 1));
            var controls = FindElementsAtCoordinates(point);
        }

        private UIElement[] FindElementsAtCoordinates(Point point)
        {
            if ((this.Orientation & PageOrientation.Portrait) == 0)
            {
                if (this.Orientation == PageOrientation.LandscapeLeft)
                    point = new Point(
                        this.ActualHeight - point.Y,
                        point.X + (SystemTray.IsVisible ? 72 : 0));
                else
                    point = new Point(
                        point.Y,
                        this.ActualWidth - point.X + (SystemTray.IsVisible ? 72 : 0));
            }

            return VisualTreeHelper.FindElementsInHostCoordinates(
                new Point(point.X, point.Y + (SystemTray.IsVisible ? 72 : 0)),
                page).ToArray();
        }
    }
}

XAML：

<phone:PhoneApplicationPage
    x:Class="PhoneApp4.MainPage"
    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"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Landscape"
    Orientation="Landscape"
    mc:Ignorable="d"
    d:DesignHeight="480"
    d:DesignWidth="728"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid
        x:Name="LayoutRoot"
        Background="Transparent">
        <Border
            x:Name="border1"
            Width="100"
            Height="100"
            VerticalAlignment="Bottom"
            HorizontalAlignment="Left"
            BorderThickness="5"
            BorderBrush="Red" />
        <Border
            x:Name="border2"
            Width="100"
            Height="100"
            VerticalAlignment="Bottom"
            HorizontalAlignment="Center"
            BorderThickness="5"
            BorderBrush="Orange" />
    </Grid>

    <phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True" Mode="Minimized">
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Button 1"/>
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button2.png" Text="Button 2"/>
            <shell:ApplicationBar.MenuItems>
                <shell:ApplicationBarMenuItem Text="MenuItem 1"/>
                <shell:ApplicationBarMenuItem Text="MenuItem 2"/>
            </shell:ApplicationBar.MenuItems>
        </shell:ApplicationBar>
    </phone:PhoneApplicationPage.ApplicationBar>
</phone:PhoneApplicationPage>