如何修复android上谷歌地图中的com.google.android.gms.maps.model.Marker com.google.android.gms.maps.GoogleMap.addMarker

我想在我的应用程序中使用谷歌地图。对于创建

谷歌地图

我使用此修补程序：新建->谷歌->谷歌地图活动，我在下面写代码，但在运行show me Force Close error时。
映射活动代码：

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    @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);

        setUpMap();
    }


    /**
     * 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;

        // 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 setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker").snippet("Snippet"));

        // Enable MyLocation Layer of Google Map
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        mMap.setMyLocationEnabled(true);

        // Get LocationManager object from System Service LOCATION_SERVICE
        LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        // Create a criteria object to retrieve provider
        Criteria criteria = new Criteria();

        // Get the name of the best provider
        String provider = locationManager.getBestProvider(criteria, true);

        // Get Current Location
        Location myLocation = locationManager.getLastKnownLocation(provider);

        // set map type
        mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

        // Get latitude of the current location
        double latitude = myLocation.getLatitude();

        // Get longitude of the current location
        double longitude = myLocation.getLongitude();

        // Create a LatLng object for the current location
        LatLng latLng = new LatLng(latitude, longitude);

        // Show the current location in Google Map
        mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));

        // Zoom in the Google Map
        mMap.animateCamera(CameraUpdateFactory.zoomTo(14));
        mMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("You are here!").snippet("Consider yourself located"));
    }
}

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:map="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.tellfa.googlepluslogin.map.MapsActivity" />

XML代码：

public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    @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);

        setUpMap();
    }


    /**
     * 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;

        // 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 setUpMap() {
        mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker").snippet("Snippet"));

        // Enable MyLocation Layer of Google Map
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            // TODO: Consider calling
            //    ActivityCompat#requestPermissions
            // here to request the missing permissions, and then overriding
            //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
            //                                          int[] grantResults)
            // to handle the case where the user grants the permission. See the documentation
            // for ActivityCompat#requestPermissions for more details.
            return;
        }
        mMap.setMyLocationEnabled(true);

        // Get LocationManager object from System Service LOCATION_SERVICE
        LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        // Create a criteria object to retrieve provider
        Criteria criteria = new Criteria();

        // Get the name of the best provider
        String provider = locationManager.getBestProvider(criteria, true);

        // Get Current Location
        Location myLocation = locationManager.getLastKnownLocation(provider);

        // set map type
        mMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);

        // Get latitude of the current location
        double latitude = myLocation.getLatitude();

        // Get longitude of the current location
        double longitude = myLocation.getLongitude();

        // Create a LatLng object for the current location
        LatLng latLng = new LatLng(latitude, longitude);

        // Show the current location in Google Map
        mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));

        // Zoom in the Google Map
        mMap.animateCamera(CameraUpdateFactory.zoomTo(14));
        mMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longitude)).title("You are here!").snippet("Consider yourself located"));
    }
}

<fragment xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:map="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/map"
    android:name="com.google.android.gms.maps.SupportMapFragment"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.tellfa.googlepluslogin.map.MapsActivity" />

---

如何解决此问题？

mMap为空，因为您从

onCreate（）

调用

setUpMap（）

，但此时映射尚未初始化。它将在

onMapReady（）

方法中初始化

---

您应该将

setUpMap（）

调用移动到

onMapReady（）

我对此不太了解，但我认为您的错误在这一行：

mMap.addMarker(new MarkerOptions().position(new LatLng(0,       0)).title("Marker").snippet("Snippet"));

mMap需要先初始化，然后才能向其添加标记，请尝试在onMapReady（）中调用setUpMap（）

下面是我目前正在使用的代码片段

XML

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <fragment
        android:id="@+id/googleMap"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.SupportMapFragment"
        android:layout_above="@+id/latlongLocation" />

    <TextView
        android:id="@+id/latlongLocation"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:gravity="bottom"
        android:layout_alignParentBottom="true"
        android:background="#ff058fff"
        android:paddingTop="5dp"
        android:paddingBottom="5dp"
        android:textColor="#ffffffff"
        android:paddingLeft="5dp"
        android:paddingRight="5dp" />
</RelativeLayout>

注意：应用运行时权限以及您在OP中使用的权限。

private void setUpMap（）{
-->mMap=谷歌地图；
mMap.addMarker（newmarkeroptions（）.position（newlatlng（0，0））.title（“Marker”）.snippet（“snippet”）；

也发布你的

XML

代码。@jaydroider，我在上面上传。请看这个你到底在做什么？显示当前位置还是什么？你想在地图上显示当前位置？显示Frice close Error你想在地图上显示当前位置？

com.tellfa.googlepluslogin，PID:7265 java.lang.NullPointerException:尝试在com.tellfa.googlepluslogin.map.MapsActivity.setUpMap（MapsActivity.java:90）上的空对象引用上调用虚拟方法“double android.location.location.getLatitude（）”在com.tellfa.googlepluslogin.map.MapsActivity.onMapReady（MapsActivity.java:55）

@Palang显然

myLocation

是空的。我不知道为什么。的文档说“如果提供程序当前被禁用，则返回空的。”@MohammadNouri您发现了评论中的问题吗？如果是，请与我共享。谢谢，但现在请向我显示以下错误：

java.lang.RuntimeException:无法启动活动组件信息{com.tellfa.googlepluslogin/com.tellfa.googlepluslogin.map.MapsActivity}：java.lang.NullPointerException:尝试在空对象引用上调用虚拟方法“com.google.android.gms.maps.google.android.gms.maps.SupportMapFragment.getMap（）”

@Palang将此代码更改为

getActivity（）.getSupportFragmentManager（）.findFragmentById（R.id.GoogleMap））.getMap（）；

@Palang Up投票表决答案，这样对其他人会有帮助。谢谢：）。

 <uses-permission android:name="com.javapapers.currentlocationinmap.permission.MAPS_RECEIVE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" />
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />