如何获取访问地图边界矩形？
在WP7 Bing Map中，我可以使用属性BoundingRectangle，但在新的诺基亚地图中，我看不到类似的属性。
感谢提前。
答案 0 :(得分：4)
我的方法是简单地为Map控件添加一个扩展方法，该方法使用控件上的ConvertViewportPointToGeoCoordinate方法返回边界矩形：
public static class MapExtensions
{
/// <summary>
/// Returns the bounding rectangle representing the area displayed by the map contorl.
/// </summary>
/// <param name="map">The map control whose bounding rectangle should be returned.</param>
/// <returns>The bounding rectangle representing the area displayed by the map contorl.</returns>
public static MapBoundingRectangle GetBoundingRectangle( this Microsoft.Phone.Maps.Controls.Map map )
{
var lowerLeft = map.ConvertViewportPointToGeoCoordinate( new System.Windows.Point( 0, map.ActualHeight ) );
var upperRight = map.ConvertViewportPointToGeoCoordinate( new System.Windows.Point( map.ActualWidth, 0 ) );
return new MapBoundingRectangle( lowerLeft, upperRight );
}
}
MapBoundingRectangle只是一个简单的助手类：
public class MapBoundingRectangle
{
#region -- Class constants
/// <summary>
/// The minimum value for a longitude (East-West position).
/// </summary>
public const double MinimumLongitude = -180;
/// <summary>
/// The maximum value for a longitude (East-West position).
/// </summary>
public const double MaximumLongitude = 180;
/// <summary>
/// The minimum value for a latitude (North-South position).
/// </summary>
public const double MinimumLatitude = -90;
/// <summary>
/// The maximum value for a latitude (North-South position).
/// </summary>
public const double MaximumLatitude = 90;
#endregion
#region -- Constructors
/// <summary>
/// Creates a bounding rectangle using the provided coordinates.
/// </summary>
/// <param name="lowerLeftLatitude">The latitude of the lower-left corner of the bounding rectangle.</param>
/// <param name="lowerLeftLongitude">The longitude of the lower-left corner of the bounding rectangle.</param>
/// <param name="upperRightLatitude">The latitude of the upper-right corner of the bounding rectangle.</param>
/// <param name="upperRightLongitude">The longitude of the upper-right corner of the bounding rectangle.</param>
/// <exception cref="ArgumentException">
/// Thrown if any of the provided coordinates contains an invalid value or if the two corner coordinates
/// don't define a rectangle (i.e. if the lower-left and upper-right coordinates are swapped).
/// </exception>
public MapBoundingRectangle( double lowerLeftLatitude, double lowerLeftLongitude, double upperRightLatitude, double upperRightLongitude )
{
if ( lowerLeftLatitude < MinimumLatitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_LatitudeTooSmall, "lowerLeftLatitude" );
}
if ( lowerLeftLatitude > MaximumLatitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_LatitudeTooBig, "lowerLeftLatitude" );
}
if ( upperRightLatitude < MinimumLatitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_LatitudeTooSmall, "upperRightLatitude" );
}
if ( upperRightLatitude > MaximumLatitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_LatitudeTooBig, "upperRightLatitude" );
}
if ( lowerLeftLongitude < MinimumLongitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_LatitudeTooSmall, "lowerLeftLongitude" );
}
if ( lowerLeftLongitude > MaximumLongitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_LatitudeTooBig, "lowerLeftLongitude" );
}
if ( upperRightLongitude < MinimumLongitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_LatitudeTooSmall, "upperRightLongitude" );
}
if ( upperRightLongitude > MaximumLongitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_LatitudeTooBig, "upperRightLongitude" );
}
if ( lowerLeftLatitude > upperRightLatitude || lowerLeftLongitude > upperRightLongitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_NotARectangle );
}
LowerLeft = new GeoCoordinate( lowerLeftLatitude, lowerLeftLongitude );
UpperRight = new GeoCoordinate( upperRightLatitude, upperRightLongitude );
}
/// <summary>
/// Creates a bounding rectangle using the provided coordinates.
/// </summary>
/// <param name="lowerLeft">The lower-left (south-west) corner of the bounding rectangle.</param>
/// <param name="upperRight">The upper-right (north-east) corner of the bounding rectangle.</param>
/// <exception cref="ArgumentException">
/// Thrown if the two corner coordinates don't define a rectangle (i.e. if the lower-left and upper-right coordinates are swapped).
/// </exception>
/// <exception cref="ArgumentNullException">
/// Thrown if either <paramref name="lowerLeft"/> or <paramref name="upperRight"/> is <c>null</c>
/// or <see cref="GeoCoordinate.Unknown"/>.
/// </exception>
public MapBoundingRectangle( GeoCoordinate lowerLeft, GeoCoordinate upperRight )
{
if ( lowerLeft == null || lowerLeft == GeoCoordinate.Unknown )
{
throw new ArgumentNullException( "lowerLeft" );
}
if ( upperRight == null || upperRight == GeoCoordinate.Unknown )
{
throw new ArgumentNullException( "upperRight" );
}
if ( lowerLeft.Latitude > upperRight.Latitude || lowerLeft.Longitude > upperRight.Longitude )
{
throw new ArgumentException( Resources.Resources.MapBoundingRectangle_NotARectangle );
}
LowerLeft = lowerLeft;
UpperRight = upperRight;
}
#endregion
#region -- Public properties
/// <summary>
/// The lower left (south-west) corner of the bounding rectangle.
/// </summary>
public GeoCoordinate LowerLeft { get; private set; }
/// <summary>
/// The upper right (north-east) corner of the bounding rectangle.
/// </summary>
public GeoCoordinate UpperRight { get; private set; }
#endregion
#region -- Public methods
/// <summary>
/// Determines if this bounding rectangle completely contains
/// <paramref name="otherRectangle"/>.
/// </summary>
/// <param name="otherRectangle">The other <see cref="MapBoundingRectangle"/> to check.</param>
/// <returns>
/// <c>true</c> if <paramref name="otherRectangle"/> is completely within this bounding
/// rectangle, <c>false</c> otherwise.
/// </returns>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="otherRectangle"/> is <c>null</c>.</exception>
public bool Contains( MapBoundingRectangle otherRectangle )
{
if ( otherRectangle == null )
{
throw new ArgumentNullException( "otherRectangle" );
}
bool lowerLeftContained = ( otherRectangle.LowerLeft.Latitude >= LowerLeft.Latitude && otherRectangle.LowerLeft.Longitude >= LowerLeft.Longitude );
bool upperRightContained = ( otherRectangle.UpperRight.Latitude <= UpperRight.Latitude && otherRectangle.UpperRight.Longitude <= UpperRight.Longitude );
return ( lowerLeftContained && upperRightContained );
}
/// <summary>
/// Returns the width (in meters) of the bounding rectangle.
/// </summary>
/// <returns>The width (in meters) of the bounding rectangle.</returns>
public double GetWidth()
{
GeoCoordinate leftEdge = LowerLeft;
GeoCoordinate rightEdge = new GeoCoordinate( LowerLeft.Latitude, UpperRight.Longitude );
return Math.Abs( leftEdge.GetDistanceTo( rightEdge ) );
}
/// <summary>
/// Returns the height (in meters) of the bounding rectangle.
/// </summary>
/// <returns>The height (in meters) of the bounding rectangle.</returns>
public double GetHeight()
{
GeoCoordinate bottomEdge = LowerLeft;
GeoCoordinate upperEdge = new GeoCoordinate( UpperRight.Latitude, LowerLeft.Longitude );
return Math.Abs( bottomEdge.GetDistanceTo( upperEdge ) );
}
#endregion
}
可能不是最棒的解决方案，但它解决了我的需求，所以我希望它有所帮助。
答案 1 :(得分：0)
尝试
GeoCoordinate topLeft = Map.ConvertViewportPointToGeoCoordinate(new Point(0, 0));
GeoCoordinate bottomRight = Map.ConvertViewportPointToGeoCoordinate(new Point(e.NewSize.Width, e.NewSize.Height));
var bounds = LocationRectangle.CreateBoundingRectangle(topLeft, bottomRight);
请参阅位置矩形文档