安卓谷歌地图 : How to calculate the distance between the middle of the screen/map and the top of the screen

Question

我正在尝试计算从屏幕/ map (显示)中间到屏幕顶部的距离。我有某种算法可以执行此操作，但我不确定它是否正常工作。我收到 6367 及以上的数字。这是我的算法:

    double Radius = 6367.45;
    LatLngBounds bounds = map.getProjection().getVisibleRegion().latLngBounds;

    LatLng center = bounds.getCenter();
    LatLng north = bounds.northeast;

    // Convert lat or lng from decimal degrees into radians (divide by 57.2958)
    double centerLat = center.latitude / 57.2958;
    double centerLong = center.longitude / 57.2958;
    double northLat = north.latitude / 57.2958;
    double northLong = north.longitude / 57.2958;

    // distance = circle radius from center to top of the screen
    // this I ma not sure if it returns true numbers like amm real distance
    // and I call it in the setOnCameraChangeListener on every zoom right?
    // yes
    boundRadius = Radius*(Math.acos(Math.sin(centerLat) * Math.sin(northLat) + Math.cos(centerLat)*Math.cos(northLat)*Math.cos(northLong - centerLong)));

我计算正确吗？如果不是，我做错了什么？

Answer 1

你可以只使用distanceBetween() (documentation) .我相信它考虑了地球的曲率。