Silverlight bing maps 怎么显示限定区域和限定zoomlevel的地图

Question

比如我只要显示某个城市的地图，但是我不希望浏览者再往上缩小，并且限制其只能看到本城市的地图，我用的是瓦片数据，谢谢

Answer 1

您可以定制MapMode，我是根据这位仁兄的代码修改的，具体您可以参考他的blog：

http://www.cnblogs.com/LionGG/archive/2009/11/17/1604987.html

 

public class ChinaMode : RoadMode
{
  private readonly Range<double> validLatitudeRange = new Range<double> (3.92, 53.51);
  private readonly Range<double> validLongitudeRange = new Range<double> (73.60, 135.01);

  public ChinaMode ()
  {
    var tileLayer = (MapTileLayer)this.Content;
    tileLayer.TileSources.Clear ();

    var tileSourceUri = new UriBuilder (
      "http://r2.tiles.ditu.live.com/tiles/r{quadkey}.png?g=41");
    var tileSource =
      new LocationRectTileSource (tileSourceUri.Uri.ToString (),
      new LocationRect (new Location (-90, -180), new Location (90, 180)),
      new Range<double> (1, 21));
    tileLayer.TileSources.Add (tileSource);
  }

  protected override Range<double> GetZoomRange (Location center)
  {
    return new Range<double> (10, 14);
  }

  public override bool ConstrainView (Location center, ref double zoomLevel, ref double heading, ref double pitch)
  {
    bool isChanged = base.ConstrainView (center, ref zoomLevel, ref heading, ref pitch);
    double newLatitude = center.Latitude;
    double newLongitude = center.Longitude;
    if (center.Longitude > validLongitudeRange.To)
    {
      newLongitude = validLongitudeRange.To;
    }
    else if (center.Longitude < validLongitudeRange.From)
    {
      newLongitude = validLongitudeRange.From;
    }
    if (center.Latitude > validLatitudeRange.To)
    {
      newLatitude = validLatitudeRange.To;
    }
    else if (center.Latitude < validLatitudeRange.From)
    {
      newLatitude = validLatitudeRange.From;
    }
    if (newLatitude != center.Latitude || newLongitude != center.Longitude)
    {
      center.Latitude = newLatitude;
      center.Longitude = newLongitude;
      isChanged = true;
    }
    Range<double> range = GetZoomRange (center);
    if (zoomLevel > range.To)
    {
      zoomLevel = range.To;
      isChanged = true;
    }
    else if (zoomLevel < range.From)
    {
      zoomLevel = range.From;
      isChanged = true;
    }
    return isChanged;
  }
}

在GetZoomRange方法的覆写中，可以限定允许的缩放级别，ConstrainView方法限定显示的区域。

 

Answer 2

学习了，楼上正解。

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Answer 3

:)我也是前不久才学习的。