最近使用arcgis for android 實現一些功能,如何實現圖層中所有元素居中呢?
eg:有兩個點A(ax,ay),B(bx,by),實現在圖層中居中
以下爲實現代碼:
import com.esri.core.geometry.Point
public void zoomToCenter(){
//lonA,latA爲A點的經緯度
//將經緯度轉成地圖參考的座標點
Point pntA = (Point)GeometryEngine.project(lonA, latA, mapSr)
Point pntB = (Point)GeometryEngine.project(lonB, latB, mapSr)
//計算A,B點在屏幕上的像素點
Point screenPntA = mapView.toScreenPoint(pntA);
com.esri.core.geometry.Point screenPntB = mapView.toScreenPoint(pntB);
//計算縮放比例
double s = Math.max(screenCp.getX() - screenSp.getX(), screenCp.getY() - screenSp.getY()) / (Math.min(mapView.getWidth(), mapView.getHeight())) ;
mapView.setScale(mapView.getScale() * s);
//計算中心點
com.esri.core.geometry.Point centerP = new Point(Math.abs(Math.sqrt(
(pntA.getX() - pntB.getX()) * (pntA.getX() - pntB.getX()) +
(pntA.getY() - pntB.getY()) * (pntA.getY() - pntB.getY())
)));
//將中心點位置移動到屏幕中心
mapView.centerAt(centerP, true);
}