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

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);

其他回答

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

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

注意-这不是原始问题的解决方案。这是上面讨论的子问题之一的解决方案。

解决方案@andr澄清2 -

当边界中只有一个标记时,缩放级别被设置为非常高的级别(级别21),这真的很有问题。谷歌不提供任何设置最大缩放级别的方法。当有多个标记但它们彼此非常接近时,也会发生这种情况。同样的问题也会出现。

解决方案-假设你想让你的地图永远不超过16缩放级别。然后在做了

CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, padding);
mMap.moveCamera(cu);

检查你的缩放级别是否超过了16级(或任何你想要的)

float currentZoom = mMap.getCameraPosition().zoom;

如果这个级别大于16,只有当标记非常少或所有标记彼此非常接近时才会出现这种情况,那么只需将缩放级别设置为16,就可以在特定位置缩小地图。

mMap.moveCamera(CameraUpdateFactory.zoomTo(16));

这样你就永远不会有“奇怪的”缩放级别的问题,@andr解释得很好。