PushPin和错误UIElement.Arrange(finalRect)不能用finalReck中的Infinite

Question

我的windows手机应用程序有问题。我在谷歌上找到了解决方案，但我发现更好的办法是再重写一次那个页面，所以我这样做了，但我仍然有这个错误，我不知道为什么。这是我的xaml代码

<phone:PhoneApplicationPage 
    x:Class="GeoWatcher.Watch"
    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="Portrait" Orientation="Portrait"
    mc:Ignorable="d" d:DesignHeight="768" d:DesignWidth="480"
    shell:SystemTray.IsVisible="True" xmlns:my="clr-namespace:Microsoft.Phone.Controls.Maps;assembly=Microsoft.Phone.Controls.Maps" Loaded="PhoneApplicationPage_Loaded">
    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock x:Name="AplicationTitleTextBox" Text="GeoWatcher" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock x:Name="PageTitle" Text="Your trip" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>
        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <my:Map Height="500" HorizontalAlignment="Left" Margin="0,101,0,0" Name="MyMap" VerticalAlignment="Top" Width="450" CredentialsProvider=""/>
            <Button Content="Button" Height="72" HorizontalAlignment="Left" Margin="290,23,0,0" Name="StopButton" VerticalAlignment="Top" Width="160" />
            <TextBlock Height="30" HorizontalAlignment="Left" Margin="12,47,0,0" Name="DistanceTextBlock" Text="TextBlock" VerticalAlignment="Top" />
        </Grid>
    </Grid>
    <!--Sample code showing usage of ApplicationBar-->
    <!--<phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True">
            <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>

这是我的C#代码

public partial class Watch : PhoneApplicationPage
    {
        public IsolatedStorageFile myStore;
        GeoCoordinate destinationPointPosition;
        Pushpin destinationPointPushPin;
        Pushpin actualPositionPushPin;
        GeoCoordinateWatcher watcher;

        public Watch()
        {
            InitializeComponent();
        }
        private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
        {
            this.myStore = IsolatedStorageFile.GetUserStoreForApplication();
            this.DistanceTextBlock.Text = "";
            loadSelectedPoint();
            this.destinationPointPushPin = new Pushpin();
            this.destinationPointPushPin.Location = this.destinationPointPosition;
            this.MyMap.Children.Add(destinationPointPushPin);
            this.watcher = new GeoCoordinateWatcher();
            this.watcher.PositionChanged += new EventHandler<GeoPositionChangedEventArgs<GeoCoordinate>>(watcher_PositionChanged);
            this.watcher.Start();
            this.actualPositionPushPin = new Pushpin();
            this.actualPositionPushPin.Location = this.watcher.Position.Location;
            this.MyMap.Children.Add(this.actualPositionPushPin);
            this.MyMap.SetView(this.actualPositionPushPin.Location, 12);
        }
        void watcher_PositionChanged(object sender, GeoPositionChangedEventArgs<GeoCoordinate> e)
        {
            this.actualPositionPushPin.Location = e.Position.Location;  
        }
        private void loadSelectedPoint()
        {
            try
            {
                using (var isoFileStream = new IsolatedStorageFileStream("folder\selected.txt", FileMode.Open, myStore))
                {
                    // Read the data.
                    using (var isoFileReader = new StreamReader(isoFileStream))
                    {
                        String temp = isoFileReader.ReadLine();
                        string[] tab = temp.Split('@');
                        GeoCoordinate geo = new GeoCoordinate(double.Parse(tab[1]), double.Parse(tab[2]));
                        this.destinationPointPosition = geo;
                    }
                }
            }
            catch (Exception b)
            {
                MessageBox.Show(b.Message);
            }
        }
    }

我检查了一下，它从文件中正确加载了数据。问题是我猜有图钉，但我不知道如何解决。

Answer 1

您不能将PushPin.Location设置为未知的GeoCoordinate值。检查GeoCoordinate的IsUnknown属性，如果它是真的，不要显示你的图钉。