Android导航抽屉谷歌地图片段错误如何解决？

时间：2016-08-25 01:19:34

标签： android google-maps navigation-drawer

我该如何解决这个问题？

GmapFragment.java

此行我收到错误

fragment.getMapAsync（this）

显示java.lang.NullPointerException

我附上了logcat

我一直在编辑这段代码2天

无法找到解决方案。

我的源代码是用户点击导航抽屉时运行Google地图。

当我点击抽屉菜单时。

我收到错误java.lang.NullPointerException

MainActivity.java 

package youtube.demo.youtubedemo;

import android.app.FragmentManager;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;

import youtube.demo.youtubedemo.Fragments.GmapFragment;
import youtube.demo.youtubedemo.Fragments.ImportFragment;
import youtube.demo.youtubedemo.Fragments.MainFragment;

public class MainActivity extends AppCompatActivity
    implements NavigationView.OnNavigationItemSelectedListener {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);

        FragmentManager fm = getFragmentManager();
        fm.beginTransaction().replace(R.id.content_frame, new MainFragment()).commit();

}

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
        public boolean onNavigationItemSelected(MenuItem item) {
        FragmentManager fm = getFragmentManager();

        int id = item.getItemId();

        if (id == R.id.nav_camara) {
            fm.beginTransaction().replace(R.id.content_frame, new ImportFragment()).commit();
        } else if (id == R.id.nav_gallery) {
            fm.beginTransaction().replace(R.id.content_frame, new GmapFragment()).commit();
        } else if (id == R.id.nav_slideshow) {

        } else if (id == R.id.nav_manage) {

        } else if (id == R.id.nav_share) {

        } else if (id == R.id.nav_send) {

        }
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }

    }

MainFragment.java 

package youtube.demo.youtubedemo.Fragments;

import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import youtube.demo.youtubedemo.R;

public class MainFragment extends Fragment {

        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            return inflater.inflate(R.layout.fragment_main,container,false);
        }
    }

ImportFragment.java 

package youtube.demo.youtubedemo.Fragments;

import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;


import youtube.demo.youtubedemo.R;

public class ImportFragment extends Fragment {

        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            return inflater.inflate(R.layout.fragment_import, container,false);
    }

        @Override
        public void onViewCreated(View view, Bundle savedInstanceState) {
            super.onViewCreated(view, savedInstanceState);
    }

}

GmapFragment.java 

package youtube.demo.youtubedemo.Fragments;

import android.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

import youtube.demo.youtubedemo.R;

public class GmapFragment extends Fragment implements OnMapReadyCallback {


        @Nullable
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,     Bundle savedInstanceState) {
            return inflater.inflate(R.layout.fragment_gmaps, container,false);
    }

        @Override
        public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        MapFragment fragment = (MapFragment)this.getChildFragmentManager().findFragmentById(R.id.map);
        fragment.getMapAsync(this);
}

    @Override
    public void onMapReady(GoogleMap googleMap) {

        LatLng marker = new LatLng(-33.867, 151.206);

        googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(marker, 13));

        googleMap.addMarker(new MarkerOptions().title("Hello Google Maps!").position(marker));
    }
}

fragment_main.xml 

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="Main Fragment"
        android:id="@+id/textView2"
        android:layout_gravity="center" />
</FrameLayout>

fragment_import.xml 

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"     android:layout_height="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceMedium"
        android:text="Import Fragment"
        android:id="@+id/textView2"
        android:layout_gravity="center" />
 </FrameLayout>

fragment_gmaps.xml 

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">

    <fragment android:id="@+id/map"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        class="com.google.android.gms.maps.MapFragment"></fragment>

</FrameLayout>







08-25 09:38:01.621 22053-22053/youtube.demo.youtubedemo E/AndroidRuntime: FATAL EXCEPTION: main
                                                                      Process: youtube.demo.youtubedemo, PID: 22053
                                                                      java.lang.NullPointerException
                                                                          at youtube.demo.youtubedemo.Fragments.GmapFragment.onViewCreated(GmapFragment.java:35)
                                                                          at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:904)
                                                                          at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
                                                                          at android.app.BackStackRecord.run(BackStackRecord.java:684)
                                                                          at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1453)
                                                                          at android.app.FragmentManagerImpl$1.run(FragmentManager.java:443)
                                                                          at android.os.Handler.handleCallback(Handler.java:733)
                                                                          at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                          at android.os.Looper.loop(Looper.java:146)
                                                                          at android.app.ActivityThread.main(ActivityThread.java:5602)
                                                                          at java.lang.reflect.Method.invokeNative(Native Method)
                                                                          at java.lang.reflect.Method.invoke(Method.java:515)
                                                                          at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
                                                                          at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
                                                                          at dalvik.system.NativeStart.main(Native Method)
08-25 09:38:03.596 22053-22161/youtube.demo.youtubedemo W/DynamiteModule: Local module descriptor class for com.google.android.gms.googlecertificates not found.
08-25 09:38:03.601 22053-22161/youtube.demo.youtubedemo I/DynamiteModule: Considering local module com.google.android.gms.googlecertificates:0 and remote module com.google.android.gms.googlecertificates:1
08-25 09:38:03.601 22053-22161/youtube.demo.youtubedemo I/DynamiteModule: Selected remote version of com.google.android.gms.googlecertificates, version >= 1
08-25 09:38:03.601 22053-22161/youtube.demo.youtubedemo D/ChimeraFileApk: Primary ABI of requesting process is armeabi-v7a
08-25 09:38:03.601 22053-22161/youtube.demo.youtubedemo D/ChimeraFileApk: Classloading successful. Optimized code found.
08-25 09:38:03.606 22053-22161/youtube.demo.youtubedemo D/GoogleCertificates: com.google.android.gms.googlecertificates module is loaded
08-25 09:38:03.636 22053-22161/youtube.demo.youtubedemo D/GoogleCertificatesImpl: Fetched 163 Google release certificates
08-25 09:38:03.666 22053-22161/youtube.demo.youtubedemo D/GoogleCertificatesImpl: Fetched 318 Google certificates

1 个答案:

答案 0 :(得分：1)

有步骤你必须确保你已经开始接收地图，比如获得有效的谷歌地图api密钥流tutorial。

根据您的代码，您需要转到onCreateView 

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
   View mView = inflater.inflate(R.layout.fragment_gmaps, container, false);
   MapFragment fragment = (MapFragment)this.getChildFragmentManager().findFragmentById‌​‌​(R.id.map); 
   fragment.getMapAsync(this);
   return mView ;

希望这个帮助

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