Question

我正在尝试计算从屏幕/地图中间（显示）到屏幕顶部的距离。我有一些算法可以做到这一点，但我不确定它是否正常工作。我得到像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)));

我是否正确计算？如果没有，我做错了什么？

Answer 1

You could just use distanceBetween() (documentation). I believe it takes the curvature of the Earth into consideration.

Android谷歌地图：如何计算屏幕/地图中间与屏幕顶部之间的距离

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