mClustermanager.additem() google 映射抛出空指针异常 android
mClustermanager.additem() google maps throwing null pointer exception android
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
MyItem myItem;
private ClusterManager<MyItem> mClusterManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(31.530136,74.353225), 10));
// Initialize the manager with the context and the map.
// (Activity extends context, so we can pass 'this' in the constructor.)
mClusterManager = new ClusterManager<MyItem>(this, mMap);
// Point the map's listeners at the listeners implemented by the cluster
// manager.
mMap.setOnCameraChangeListener(mClusterManager);
mMap.setOnMarkerClickListener(mClusterManager);
// Add cluster items (markers) to the cluster manager.
// addItems();
myItem = new MyItem(31.530136,74.353225);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.529807, 74.352495);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.530584, 74.353729);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.531319, 74.351217);
mClusterManager.addItem(myItem);
// Add a marker in Sydney and move the camera
// LatLng sydney = new LatLng(-34, 151);
// mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
// mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
private void addItems() {
// Set some lat/lng coordinates to start with.
double lat = 31.531034;
double lng = 74.352374;
// Add ten cluster items in close proximity, for purposes of this example.
for (int i = 0; i < 10; i++) {
double offset = i / 60d;
lat = lat + offset;
lng = lng + offset;
MyItem offsetItem = new MyItem(lat, lng);
mClusterManager.addItem(offsetItem);
}
}
}
以上class表示在android中Google地图提供的集群实用库中添加标记坐标的代码。但是当我 运行 它给出错误的代码时 mClustermanager.addItem() 给出了空指针异常。
I actually found a couple of issues (Issue 7696 and Issue 9021) logged in gmaps-api-issues.
但是,我不太确定您的案例是否与这些现有问题有某种关联。
但是,您可以尝试给定的解决方法:
User's upgrading Google Play Services on their device to 9.0.83 will fix this issue. You do not need to update the SDK version.
要获得更多详细信息,此 SO post - 也可能有所帮助。
我通过从 https://developers.google.com/maps/documentation/android-sdk/utility/setup 的演示应用程序("Get the Maps SDK for Android utility library" 下的 zip 文件)复制 MyItem class 解决了这个问题
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private GoogleMap mMap;
MyItem myItem;
private ClusterManager<MyItem> mClusterManager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(31.530136,74.353225), 10));
// Initialize the manager with the context and the map.
// (Activity extends context, so we can pass 'this' in the constructor.)
mClusterManager = new ClusterManager<MyItem>(this, mMap);
// Point the map's listeners at the listeners implemented by the cluster
// manager.
mMap.setOnCameraChangeListener(mClusterManager);
mMap.setOnMarkerClickListener(mClusterManager);
// Add cluster items (markers) to the cluster manager.
// addItems();
myItem = new MyItem(31.530136,74.353225);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.529807, 74.352495);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.530584, 74.353729);
mClusterManager.addItem(myItem);
myItem = new MyItem(31.531319, 74.351217);
mClusterManager.addItem(myItem);
// Add a marker in Sydney and move the camera
// LatLng sydney = new LatLng(-34, 151);
// mMap.addMarker(new MarkerOptions().position(sydney).title("Marker in Sydney"));
// mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
}
private void addItems() {
// Set some lat/lng coordinates to start with.
double lat = 31.531034;
double lng = 74.352374;
// Add ten cluster items in close proximity, for purposes of this example.
for (int i = 0; i < 10; i++) {
double offset = i / 60d;
lat = lat + offset;
lng = lng + offset;
MyItem offsetItem = new MyItem(lat, lng);
mClusterManager.addItem(offsetItem);
}
}
}
以上class表示在android中Google地图提供的集群实用库中添加标记坐标的代码。但是当我 运行 它给出错误的代码时 mClustermanager.addItem() 给出了空指针异常。
I actually found a couple of issues (Issue 7696 and Issue 9021) logged in gmaps-api-issues.
但是,我不太确定您的案例是否与这些现有问题有某种关联。
但是,您可以尝试给定的解决方法:
User's upgrading Google Play Services on their device to 9.0.83 will fix this issue. You do not need to update the SDK version.
要获得更多详细信息,此 SO post -
我通过从 https://developers.google.com/maps/documentation/android-sdk/utility/setup 的演示应用程序("Get the Maps SDK for Android utility library" 下的 zip 文件)复制 MyItem class 解决了这个问题