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我正在努力在使用 XAML 和 C# 的 Windows 8 应用程序中将纬度和经度集合添加为 Bing 地图上的图钉。

使用事件处理程序（例如在地图上右击）一一添加图钉可以正常工作。

这是 XAML：

 <bm:Map x:Name="myMap" Grid.Row="0" MapType="Road" ZoomLevel="14" Credentials="{StaticResource BingMapAPIKey}" ShowTraffic="False" Tapped="map_Tapped" >
      <bm:Map.Center>
            <bm:Location Latitude="-37.812751" Longitude="144.968204" />
      </bm:Map.Center>
 </bm:Map>

这是处理程序：

    private void map_Tapped(object sender, TappedRoutedEventArgs e)
    {
        // Retrieves the click location
        var pos = e.GetPosition(myMap);
        Bing.Maps.Location location;
        if (myMap.TryPixelToLocation(pos, out location))
        {
            // Place Pushpin on the Map
            Pushpin pushpin = new Pushpin();
            pushpin.RightTapped += pushpin_RightTapped;
            MapLayer.SetPosition(pushpin, location);
            myMap.Children.Add(pushpin);

            // Center the map on the clicked location
            myMap.SetView(location);
        }
    }

以上所有工作。如果我点击地图，则会添加一个新的图钉。

现在，当我尝试通过迭代列表来初始化页面时添加图钉时，地图上只显示列表的最后一个图钉，就好像每个新图钉都覆盖了前一个图钉一样。这是我使用的代码：

 protected override async void LoadState(Object navigationParameter, Dictionary<String, Object> pageState)
 {
      ...

      // The Venue class is a custom class, the Latitude & Logitude are of type Double
      foreach (Venue venue _venues)
      {
           Bing.Maps.Location location = new Location(venue.Latitude, venue.Longitude);

           // Place Pushpin on the Map
           Pushpin pushpin = new Pushpin();
           pushpin.RightTapped += pushpin_RightTapped;
           MapLayer.SetPosition(pushpin, location);
           myMap.Children.Add(pushpin);

           // Center the map on the clicked location
           myMap.SetView(location);
      }

      ...
 }

如您所见，我使用相同的代码，但在 LoadState 方法的末尾，地图只显示最后一个位置。如果您想知道，foreach 循环会针对每个位置完全执行。

Is there any way to get this to work, or even better, to bind directly the map children to a ObservableCollection of Pushpin objects ? I feel like I am so close but I can't figure out what I missed.

Please help !

4

1 回答 1

2

You should keep the different locations in an array (or a list or more efficient LocationCollection) and call the SetView method only after you've looped throught your elements.

  LocationCollection locationCollection = new LocationCollection ();
  // The Venue class is a custom class, the Latitude & Logitude are of type Double
  foreach (Venue venue _venues)
  {
       Bing.Maps.Location location = new Location(venue.Latitude, venue.Longitude);

       // Place Pushpin on the Map
       Pushpin pushpin = new Pushpin();
       pushpin.RightTapped += pushpin_RightTapped;
       MapLayer.SetPosition(pushpin, location);
       myMap.Children.Add(pushpin);


       locationCollection.Append(location);
  }
  myMap.SetView(new LocationRect(locationCollection));
于 2013-02-18T13:00:11.530 回答