ArcGIS Runtime API For Android 经纬度转换为墨卡托坐标，屏幕点击坐标转换为墨卡托坐标以及距离和面积的计算 Kotlin 版

//经纬度转换为墨卡托坐标
private fun wgstmkt(a: Double,b: Double):Point{//指定返回类型
   // Log.i("测试","a ==="+a +"b=="+b);
    var wgsdian =Point(a, b)
    var wgsdian2 = GeometryEngine.project(wgsdian, SpatialReferences.getWgs84()) as Point
   var mktdian = GeometryEngine.project(wgsdian2, SpatialReferences.getWebMercator()) as Point
   return mktdian
}

//屏幕点击地图的点作为墨卡托坐标

mapView.onTouchListener = object : DefaultMapViewOnTouchListener(this, mapView) {
    override fun onSingleTapConfirmed(e: MotionEvent): Boolean {
        //获取到触摸的屏幕上的点
        val point = android.graphics.Point(e.x.toInt(), e.y.toInt())
        //转换为地图上的点
        val mapPoint: Point = mapView.screenToLocation(point)
       
        return super.onSingleTapConfirmed(e)
    }
}

//计算距离和面积

val graphicsOverlay = GraphicsOverlay()
mapView.graphicsOverlays.add(graphicsOverlay)

val polylinePointsjs = PointCollection(SpatialReferences.getWebMercator()).apply {

      add(wgstmkt(121.428731, 37.461226))
      add(wgstmkt(121.438493, 37.458680))

  }

// 从点集合创建一个折线几何
val polylinejs = Polyline(polylinePointsjs)
//根据路径计算出线的长度
val length = GeometryEngine.length(polylinejs)
val numberFormat = NumberFormat.getInstance()
numberFormat.maximumFractionDigits = 2
val s = numberFormat.format(length)
Log.i("墨卡托距离","长度：$length 米" );
Log.i("墨卡托距离保留两位","长度：$s 米" );
//////////////////////////////////用测地线的方法测距离

 val polylinePoints = PointCollection(SpatialReferences.getWgs84()).apply {
       // Point(latitude, longitude)
       add(Point(121.428731, 37.461226))
       add(Point(121.438493, 37.458680))
      // add(Point(121.447293, 37.457323))
   }

   // 从点集合创建一个折线几何
   val polyline = Polyline(polylinePoints)

   // 为折线创建一个蓝线符号
   val polylineSymbol = SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, -0xff9c01, 3f)
   val graphic2 = Graphic(polyline, polylineSymbol)
  graphicsOverlay.graphics.add(graphic2)

 
   // 用路径图形使路径密集成测地线曲线

   val pathGeometry = GeometryEngine.densifyGeodetic(
       polyline,
       1.0,
       unitOfMeasurement,
       GeodeticCurveType.GEODESIC
   )
    // 计算路径的距离   测地线方法
   val distancejl =
       GeometryEngine.lengthGeodetic(pathGeometry, unitOfMeasurement, GeodeticCurveType.GEODESIC)
   Log.i("wgs84距离","distance ==="+distancejl );

 //计算面积
val polygonPointsmjjs = PointCollection(SpatialReferences.getWebMercator()).apply {
    // 要顺时针，逆时针会出现负的
    add(wgstmkt(121.438849, 37.465382))
    add(wgstmkt(121.449894, 37.459472))
    add(wgstmkt(121.450179, 37.474063))
    add(wgstmkt(121.458159, 37.464506))

  }
// 从点集合创建一个多边形几何
val polygonmjjs = Polygon(polygonPointsmjjs)
//这里可以根据面的范围 计算面积
val areajs = GeometryEngine.area(polygonmjjs)


Log.i("面积","面积：$areajs 平方米");