android - 在 MapView Android 中选择一个区域

Question

是否可以在 android 中显示地图视图并允许用户选择一个区域，例如国家或州？

澄清：

我想让用户从地图视图中选择一个国家，这怎么可能？

我不关心所选国家是否突出显示，我只关心检索用户选择/触摸/标记的国家

Answer 1

有一种方法可以从地图中获取纬度，经度 如何从谷歌地图中获取经纬度触摸事件？

之后，您可以调用 Google Geo Code API 将此 lat,lon 转换为物理地址，

IE

http://maps.googleapis.com/maps/api/geocode/json?latlng=40.714224,-73.961452&sensor=true_or_false

上面的链接将返回 JSON

{
  "status": "OK",
  "results": [ {
    "types": street_address,
    "formatted_address": "275-291 Bedford Ave, Brooklyn, NY 11211, USA",
    "address_components": [ {
      "long_name": "275-291",
      "short_name": "275-291",
      "types": street_number
    }, {
      "long_name": "Bedford Ave",
      "short_name": "Bedford Ave",
      "types": route
    }, {
      "long_name": "New York",
      "short_name": "New York",
      "types": [ "locality", "political" ]
    }, {
      "long_name": "Brooklyn",
      "short_name": "Brooklyn",
      "types": [ "administrative_area_level_3", "political" ]
    }, {
      "long_name": "Kings",
      "short_name": "Kings",
      "types": [ "administrative_area_level_2", "political" ]
    }, {
      "long_name": "New York",
      "short_name": "NY",
      "types": [ "administrative_area_level_1", "political" ]
    }, {
      "long_name": "United States",
      "short_name": "US",
      "types": [ "country", "political" ]
    }, {
      "long_name": "11211",
      "short_name": "11211",
      "types": postal_code
    } ],
    "geometry": {
      "location": {
        "lat": 40.7142298,
        "lng": -73.9614669
      },
      "location_type": "RANGE_INTERPOLATED",
      "viewport": {
        "southwest": {
          "lat": 40.7110822,
          "lng": -73.9646145
        },
        "northeast": {
          "lat": 40.7173774,
          "lng": -73.9583193
        }
      }
    }
  },

  ... Additional results[] ...

现在您可以解析 JSON 并获取国家名称城市名称地区、州等。

或者其他选择是只获取国家代码。

http://ws.geonames.org/countryCode?lat=25.03&lng=67.2

这将返回国家代码 PK = 巴基斯坦，您可以获取国家代码列表，或者

Answer 2

我知道的一种解决方案是，您可以通过地图图钉标记特定区域，并通过在 Map 中扩展 OverLay 类来填充该区域，如下所示。希望这是有用的。

public class MapOverlay extends Overlay
{
    private GeoPoint new_geopoint = null;

    public MapOverlay(GeoPoint geoPoint) 
    {

    }

    @Override
    public void draw(Canvas canvas, MapView mapView, boolean shadow) 
    {
        super.draw(canvas, mapView, shadow);

        Paint mPaint = new Paint();
        mPaint.setDither(true);
        mPaint.setStyle(Style.FILL_AND_STROKE);
        mPaint.setColor(Color.RED);
        mPaint.setAlpha(9);
        mPaint.setStyle(Paint.Style.FILL_AND_STROKE);
        mPaint.setStrokeJoin(Paint.Join.ROUND);
        mPaint.setStrokeCap(Paint.Cap.ROUND);
        mPaint.setStrokeWidth(2);

        Path path = new Path();

        Projection projection = mapView.getProjection();

        for(int j = 0; j < geoArrayist.size(); j++) 
        {
            Iterator<GeoPoint> it = geoArrayist.iterator();
            while(it.hasNext()) 
            {
                GeoPoint arrayListGeoPoint = it.next();

                Point currentScreenPoint = new Point();
                projection.toPixels(arrayListGeoPoint, currentScreenPoint);

                if(j == 0)
                    path.moveTo(currentScreenPoint.x, currentScreenPoint.y); 
                else
                    path.lineTo(currentScreenPoint.x, currentScreenPoint.y);
            }                 
        }
       // old_geopoint = new_geopoint;
        canvas.drawPath(path, mPaint);
    }       
}