Android高德地图计算点到连线线段的最短距离

在 Android 高德地图中，计算点到连线线段的最短距离可以通过以下步骤实现：

1. 获取地图上的点和线段。

LatLng point = new LatLng(39.915168, 116.403875);
LatLng start = new LatLng(39.993015, 116.474172);
LatLng end = new LatLng(39.902981, 116.447901);
Polyline polyline = new PolylineOptions().add(start, end).color(Color.RED).width(10f);
aMap.addPolyline(polyline);

2. 计算点到线段的距离。

double distance = AMapUtils.calculateLineDistance(point, AMapUtils.nearestPointOnLine(point, start, end));

其中，nearestPointOnLine 方法可以计算点到线段的垂足，然后使用 calculateLineDistance 方法计算点到垂足的距离。

3. 显示距离信息。

Toast.makeText(this, "点到线段的最短距离为：" + distance + "米", Toast.LENGTH_SHORT).show();

完整代码如下：

public class MainActivity extends AppCompatActivity implements OnMapReadyCallback {
    private AMap aMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        MapView mapView = findViewById(R.id.map_view);
        mapView.onCreate(savedInstanceState);
        mapView.getMapAsync(this);
    }

    @Override
    public void onMapReady(AMap aMap) {
        this.aMap = aMap;

        LatLng point = new LatLng(39.915168, 116.403875);
        LatLng start = new LatLng(39.993015, 116.474172);
        LatLng end = new LatLng(39.902981, 116.447901);
        Polyline polyline = new PolylineOptions().add(start, end).color(Color.RED).width(10f);
        aMap.addPolyline(polyline);

        double distance = AMapUtils.calculateLineDistance(point, AMapUtils.nearestPointOnLine(point, start, end));

        Toast.makeText(this, "点到线段的最短距离为：" + distance + "米", Toast.LENGTH_SHORT).show();
    }

    @Override
    protected void onResume() {
        super.onResume();
        MapView mapView = findViewById(R.id.map_view);
        mapView.onResume();
    }

    @Override
    protected void onPause() {
        super.onPause();
        MapView mapView = findViewById(R.id.map_view);
        mapView.onPause();
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        MapView mapView = findViewById(R.id.map_view);
        mapView.onDestroy();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        MapView mapView = findViewById(R.id.map_view);
        mapView.onSaveInstanceState(outState);
    }
}