将 ObservableCollection 中的图钉绑定到 Bing 地图控件 WP7

Question

我正在开发 Windows Phone 7 项目 (Mango)，并尝试使用 ObservableCollection 将图钉绑定到我的 silverlight Bing Maps 控件，但它不起作用。在过去的 5 个小时里，我一直坐在这里，在 stackoverflow 上搜索互联网和其他问题，并实现了一些答案，但找不到一个有效的答案:(

如果有任何关于为什么它不起作用的想法，我将非常感激。我很确定它与我的 XAML 有关，因为我的 ObservableCollection 已使用有效位置正确填充（在运行时使用断点进行检查），目前我的 ObservableCollection 仅填充了两个位置，但我会这样做。当我开始使用 Bing RouteService 时，希望增加这个数字。

以下是代码：

public partial class MapView : PhoneApplicationPage
{
    private readonly CredentialsProvider bingMapsCredentials = new ApplicationIdCredentialsProvider(App.BingMapsKey);
    private GeoCoordinate geoDestination;
    private GeoCoordinate geoCurrentLocation;
    public ObservableCollection<PushpinModel> PushpinCollection { get; set; }

    public MapView()
    {
        InitializeComponent();

        geoDestination = new GeoCoordinate(54.975556, -1.621667);
        geoCurrentLocation = new GeoCoordinate(53.463056, -2.291389);

        CreatePushpins();
    }

    private void CreatePushpins()
    {
        PushpinModel currentLocationModel = new PushpinModel();
        PushpinModel destinationLocationModel = new PushpinModel();

        currentLocationModel.Location = geoCurrentLocation;
        destinationLocationModel.Location = geoDestination;

        PushpinCollection = new ObservableCollection<PushpinModel>();
        PushpinCollection.Add(currentLocationModel);
        PushpinCollection.Add(destinationLocationModel);
    }

下面是 PushpinModel 类：

using System.Device.Location;

namespace NavigationApp
{
    public class PushpinModel
    {
       public GeoCoordinate Location { get; set; }
    }
}

下面是有问题的 XAML（我认为！）：

<phone:PhoneApplicationPage 
    x:Class="NavigationApp.MapView"
    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:local="clr-namespace:NavigationApp"
    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">
    <phone:PhoneApplicationPage.Resources>
        <local:PushpinModel x:Key="PushpinModel" />
        <DataTemplate x:Key="LogoTemplate">
            <my:Pushpin Location="{Binding Location}" Background="#FFB6DE2E" />
        </DataTemplate>
    </phone:PhoneApplicationPage.Resources>

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="0"/>
            <RowDefinition Height="768*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28"></StackPanel>

        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1">
            <my:Map Height="520" HorizontalAlignment="Left" Margin="6,6,0,0" Name="map1" VerticalAlignment="Top" Width="468" ZoomBarVisibility="Collapsed" ZoomLevel="1" CredentialsProvider="{Binding bingMapsCredentials}" >
                <my:MapItemsControl Name="Pushpinsss" ItemTemplate="{StaticResource LogoTemplate}" ItemsSource="{Binding PushpinCollection}" >
                 </my:MapItemsControl>
            </my:Map>
        </Grid>
    </Grid>    
</phone:PhoneApplicationPage>

如果您需要更多代码/信息，请告诉我:) 谢谢 Ryan

解决方案

将 ObservableCollection 更改为：

        private ObservableCollection<PushpinModel> PushpinCollection;
    public ObservableCollection<PushpinModel> pushpinCollection
    {
        get
        {
            return PushpinCollection;
        }
    }

XAML 现在是：

 <my:MapItemsControl Name="Pushpinsss" ItemTemplate="{StaticResource LogoTemplate}" ItemsSource="{Binding pushpinCollection}" >

Answer 1

从您的代码看来，您忘记设置 DataContext 。您可以通过以下方式执行此操作：

public MapView()
{
    InitializeComponent();

    geoDestination = new GeoCoordinate(54.975556, -1.621667);
    geoCurrentLocation = new GeoCoordinate(53.463056, -2.291389);

    CreatePushpins();
    DataContext = this;
}

由于原因，您只能绑定到属性。所以这不起作用：

private readonly CredentialsProvider bingMapsCredentials = 
    new ApplicationIdCredentialsProvider(App.BingMapsKey);

XAML：

<my:Map ...  CredentialsProvider="{Binding bingMapsCredentials}" ... />

使用包装器属性：

private readonly CredentialsProvider bingMapsCredentials = 
    new ApplicationIdCredentialsProvider(App.BingMapsKey);

public CredentialsProvider BingMapsCredentials 
{ 
     get { return bingMapsCredentials; } 
}

XAML：

<my:Map ...  CredentialsProvider="{Binding BingMapsCredentials}" ... />

有一个关于 MSDN 上的 DataBinding （这是关于 WPF 的，但大部分也适用于 WP7）