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);

用谷歌地图显示所有标记

在这些方法中存储所有标记，并自动缩放显示谷歌地图中的所有标记。

// Declare the Markers List.
List<MarkerOptions> markerList;
private BitmapDescriptor vnrPoint,banPoint;


public void storeAllMarkers()
{
      markerList=new ArrayList<>();
      markerList.removeAll(markerList);


      // latitude and longitude of Virudhunagar

      double latitude1=9.587209;
      double longitude1=77.951431;
   vnrPoint=BitmapDescriptorFactory.fromResource(R.drawable.location_icon_1);
      LatLng vnr = new LatLng(latitude1, longitude1);
      MarkerOptions vnrMarker = new MarkerOptions();
      vnrMarker.position(vnr);
      vnrMarker.icon(vnrPoint);
      markerList.add(vnrMarker);

      // latitude and longitude of Bengaluru

      double latitude2=12.972442;
      double longitude2=77.580643;

    banPoint=BitmapDescriptorFactory.fromResource(R.drawable.location_icon_2);

      LatLng ban = new LatLng(latitude2, longitude2);
      MarkerOptions bengalureMarker = new MarkerOptions();
      bengalureMarker.position(ban);
      bengalureMarker.icon(banPoint);
      markerList.add(bengalureMarker);

      // You can add any numbers of MarkerOptions like this.

     showAllMarkers();

 }


public void showAllMarkers()
{
    LatLngBounds.Builder builder = new LatLngBounds.Builder();

    for (MarkerOptions m : markerList) {
        builder.include(m.getPosition());
    }

    LatLngBounds bounds = builder.build();

    int width = getResources().getDisplayMetrics().widthPixels;
    int height = getResources().getDisplayMetrics().heightPixels;
    int padding = (int) (width * 0.30); 

    // Zoom and animate the google map to show all markers

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

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));
 } 
});

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