我在谷歌地图上有10个标记。我想要尽可能放大,并保持所有标记都在视野中?在早期版本中,这可以从zoomToSpan()实现,但在v2中,我不知道如何做到这一点。此外,我知道需要可见的圆的半径。


当前回答

我用一个片段在Kotlin中显示多个标记,解决了同样的问题

首先声明一个标记列表

private lateinit var markers: MutableList<Marker>

在分支的oncreate方法中初始化它

override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
                         ): View? {
    //initialize markers list

    markers = mutableListOf()
   
    return inflater.inflate(R.layout.fragment_driver_map, container, false)
}

在OnMapReadyCallback中将标记添加到标记列表中

private val callback = OnMapReadyCallback { googleMap ->

    map = googleMap

    markers.add(
        map.addMarker(
            MarkerOptions().position(riderLatLng)
                .title("Driver")
                .snippet("Driver")
                .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED))))


    markers.add(
        map.addMarker(
            MarkerOptions().position(driverLatLng)
                .title("Driver")
                .snippet("Driver")
                .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN))))

仍然是回调

//create builder
    val builder = LatLngBounds.builder()

    //loop through the markers list
    for (marker in markers) {

        builder.include(marker.position)
    }
    //create a bound
    val bounds = builder.build()

    //set a 200 pixels padding from the edge of the screen
    val cu = CameraUpdateFactory.newLatLngBounds(bounds,200)
    
    //move and animate the camera
    map.moveCamera(cu)
    //animate camera by providing zoom and duration args, callBack set to null
    map.animateCamera(CameraUpdateFactory.zoomTo(10f), 2000, null)

快乐的程序员们

其他回答

谷歌地图V2

以下解决方案适用于Android棉花糖6 (API 23, API 24, API 25, API 26, API 27, API 28)。它也适用于Xamarin。

LatLngBounds.Builder builder = new LatLngBounds.Builder();

//the include method will calculate the min and max bound.
builder.include(marker1.getPosition());
builder.include(marker2.getPosition());
builder.include(marker3.getPosition());
builder.include(marker4.getPosition());

LatLngBounds bounds = builder.build();

int width = getResources().getDisplayMetrics().widthPixels;
int height = getResources().getDisplayMetrics().heightPixels;
int padding = (int) (width * 0.10); // offset from edges of the map 10% of screen

CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, width, height, padding);

mMap.animateCamera(cu);

这会有帮助的。从谷歌api演示

private List<Marker> markerList = new ArrayList<>();
Marker marker = mGoogleMap.addMarker(new MarkerOptions().position(geoLatLng)
                .title(title));
markerList.add(marker);
    // Pan to see all markers in view.
    // Cannot zoom to bounds until the map has a size.
    final View mapView = getSupportFragmentManager().findFragmentById(R.id.map).getView();
    if (mapView!=null) {
        if (mapView.getViewTreeObserver().isAlive()) {
            mapView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
                @SuppressWarnings("deprecation") // We use the new method when supported
                @SuppressLint("NewApi") // We check which build version we are using.
                @Override
                public void onGlobalLayout() {
                    //Calculate the markers to get their position
                    LatLngBounds.Builder b = new LatLngBounds.Builder();
                    for (Marker m : markerList) {
                        b.include(m.getPosition());
                    }
                    // also include current location to include in the view
                    b.include(new LatLng(mLocation.getLatitude(),mLocation.getLongitude()));

                    LatLngBounds bounds = b.build();
                    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
                        mapView.getViewTreeObserver().removeGlobalOnLayoutListener(this);
                    } else {
                        mapView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                    }
                    mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, 50));
                }
            });
        }
    }

清楚的信息看这个url。 https://github.com/googlemaps/android-samples/blob/master/ApiDemos/app/src/main/java/com/example/mapdemo/MarkerDemoActivity.java

对我来说很好。

从这段代码中,我在地图屏幕上显示特定缩放的多个标记。

//声明变量

private LatLngBounds bounds;
private LatLngBounds.Builder builder;

//添加多个标记点的方法

private void drawMarker(LatLng point, String text) {

        MarkerOptions markerOptions = new MarkerOptions();
        markerOptions.position(point).title(text).icon(BitmapDescriptorFactory.fromResource(R.drawable.icon));
        mMap.addMarker(markerOptions);
        builder.include(markerOptions.getPosition());

    }

//用于在地图上添加多个可见标记

@Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;
        builder = new LatLngBounds.Builder();
    for (int i = 0; i < locationList.size(); i++) {

        drawMarker(new LatLng(Double.parseDouble(locationList.get(i).getLatitude()), Double.parseDouble(locationList.get(i).getLongitude())), locationList.get(i).getNo());

     }
     bounds = builder.build();
     CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, 0);
     mMap.animateCamera(cu);

So

我需要使用addOnGlobalLayoutListener来获得适当的示例

例如,你的谷歌地图在RelativeLayout中:

RelativeLayout mapLayout = (RelativeLayout)findViewById(R.id.map_layout);
mapLayout.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
        @Override
        public void onGlobalLayout() {
            //and write code, which you can see in answer above
        }
    });

我不能使用onGlobalLayoutlistener,所以这里有另一个解决方案来防止 “地图大小不能为0。最有可能的是,地图视图的布局还没有发生。要么等待布局发生,要么使用newLatLngBounds(LatLngBounds, int, int, int),它允许你指定地图的尺寸。

mMap.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() { 
@Override 
public void onMapLoaded() { 
    mMap.moveCamera(CameraUpdateFactory.newLatLngBounds(builder.build(), 15));
 } 
});