Question

我尝试将LocationMapFragment实现到我的ContactUsActivity中，它在第29行的LocationMapFragment中显示错误。我不知道如何初始化LocationMapFragment ...... 的错误：

05-29 12:10:37.305: E/AndroidRuntime(18087): FATAL EXCEPTION: main
05-29 12:10:37.305: E/AndroidRuntime(18087): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.jumeirah.jumeirahmap/com.jumeirah.contactus.fragments.ContactUsActivity}: java.lang.NullPointerException
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1967)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.app.ActivityThread.access$600(ActivityThread.java:127)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.os.Looper.loop(Looper.java:137)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.app.ActivityThread.main(ActivityThread.java:4441)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at java.lang.reflect.Method.invokeNative(Native Method)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at java.lang.reflect.Method.invoke(Method.java:511)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at dalvik.system.NativeStart.main(Native Method)
05-29 12:10:37.305: E/AndroidRuntime(18087): Caused by: java.lang.NullPointerException
05-29 12:10:37.305: E/AndroidRuntime(18087):    at com.jumeirah.contactus.fragments.LocationMapFragment.initilizeMap(LocationMapFragment.java:29)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at com.jumeirah.contactus.fragments.LocationMapFragment.onCreateView(LocationMapFragment.java:21)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.support.v4.app.Fragment.performCreateView(Fragment.java:1500)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1467)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:570)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1133)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.app.Activity.performStart(Activity.java:4475)
05-29 12:10:37.305: E/AndroidRuntime(18087):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1940)

活动：

package com.jumeirah.contactus.fragments;
import com.jumeirah.jumeirahmap.R;
import com.jumeirah.jumeirahmap.R.id;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;

public class ContactUsActivity extends FragmentActivity{
    private TextView propertyTextView, clubTextView, europeTextView,
            mapTextView;
    private View fragmentProperty,fragmentClub,fragmentEuropean;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.contactus_activity);
        initViews();
    }
    private void initViews() {
        android.support.v4.app.FragmentManager fragmentManager= getSupportFragmentManager();
        android.support.v4.app.FragmentTransaction fragmentTransaction=fragmentManager.beginTransaction();
        PropertySalesFragment propertySalesFragment=new PropertySalesFragment();
        fragmentTransaction.replace(R.id.contact_fragment_propertysales, propertySalesFragment);
        ClubHouseFragment clubHouseFragment=new ClubHouseFragment();
        fragmentTransaction.replace(R.id.contact_fragment_clubhouse, clubHouseFragment);
        EuropeanTourFragment europeanTourFragment=new EuropeanTourFragment();
        fragmentTransaction.replace(R.id.contact_fragment_europeantour, europeanTourFragment);
        LocationMapFragment locationMapFragment=new LocationMapFragment();
        fragmentTransaction.replace(R.id.contact_fragment_maps, locationMapFragment);
        fragmentTransaction.commit();  

        propertyTextView = (TextView) findViewById(R.id.contact_text_property);
        clubTextView = (TextView) findViewById(R.id.contact_text_club);
        europeTextView = (TextView) findViewById(R.id.contact_text_european);
        mapTextView = (TextView) findViewById(R.id.contact_text_map);

        fragmentProperty=findViewById(R.id.contact_fragment_propertysales);
        fragmentClub=findViewById(R.id.contact_fragment_clubhouse);
        fragmentEuropean=findViewById(id.contact_fragment_europeantour);
        fragmentProperty.setVisibility(View.GONE);
        fragmentClub.setVisibility(View.GONE);
        fragmentEuropean.setVisibility(View.GONE);
    }
}

LocationMapFragment：

package com.jumeirah.contactus.fragments;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.jumeirah.jumeirahmap.R;    
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

public class LocationMapFragment extends Fragment{
    private GoogleMap googleMap; 
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        initilizeMap(); 
        return inflater.inflate(R.layout.location_map_activity, container, false);
    }


    private void initilizeMap() {    
        if (googleMap == null) {
            googleMap =  ((SupportMapFragment) getFragmentManager().findFragmentById(
                    R.id.map)).getMap();
            googleMap.setMyLocationEnabled(true);
            // check if map is created successfully or not
            if (googleMap == null) {
                Toast.makeText(getApplicationContext(),
                        "Sorry! unable to create maps", Toast.LENGTH_SHORT)
                        .show();
              /*  Alert.showAlert(LocationMapActivity.this,
                        getString(R.string.error_title),
                        getString(R.string.reg_err_choose_question),
                        getString(R.string.error_positive_btn), null, true);*/
            }
        }
    }

    @Override
    public void onResume() {
        super.onResume(); 
        initilizeMap(); 
    }

    private Context getApplicationContext() {
        // TODO Auto-generated method stub
        return null;
    }

}

XML：

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/scrollView1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >


    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:animateLayoutChanges="true"
        android:orientation="vertical" >

        <View
            android:layout_width="match_parent"
            android:layout_height="5dp"
            android:background="#B313C242" />

        <TextView
            android:id="@+id/contact_text_property"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:background="#555555"
            android:gravity="center_vertical|center"
            android:paddingLeft="10dp"
            android:text="@string/contact_property_sales"
            android:textColor="#FFFFFF" />

        <View   
            android:layout_width="match_parent"
            android:layout_height="2dp"
            android:background="#B313C242" />

        <fragment 
            android:name="com.jumeirah.contactus.fragments.PropertySalesFragment"
            android:id="@+id/contact_fragment_propertysales"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

        <TextView
            android:id="@+id/contact_text_club"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:background="#555555"
            android:gravity="center_vertical|center"
            android:paddingLeft="10dp"
            android:text="@string/contact_club_house"
            android:textColor="#FFFFFF" />

        <View
            android:layout_width="match_parent"
            android:layout_height="2dp"
            android:background="#B313C242" />

       <fragment 
           android:name="com.jumeirah.contactus.fragments.ClubHouseFragment"
            android:id="@+id/contact_fragment_clubhouse"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

        <TextView
            android:id="@+id/contact_text_european"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:background="#555555"
            android:gravity="center_vertical|center"
            android:paddingLeft="10dp"
            android:text="@string/contact_european_tour_int"
            android:textColor="#FFFFFF" />

        <View
            android:layout_width="match_parent"
            android:layout_height="2dp"
            android:background="#B313C242" />

        <fragment 
            android:name="com.jumeirah.contactus.fragments.EuropeanTourFragment"
            android:id="@+id/contact_fragment_europeantour"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"/>

        <TextView
            android:id="@+id/contact_text_map"
            android:layout_width="match_parent"
            android:layout_height="30dp"
            android:background="#555555"
            android:gravity="center_vertical|center"
            android:paddingLeft="10dp"
            android:text="@string/contact_location_map"
            android:textColor="#FFFFFF" />

        <View
            android:layout_width="match_parent"
            android:layout_height="2dp"
            android:background="#B313C242" />

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


</ScrollView>

清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.jumeirah.jumeirahmap"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="11"
        android:targetSdkVersion="18" />

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

    <!-- Required to show current location -->
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true" >
    </uses-feature>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.jumeirah.contactus.fragments.ContactUsActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="AIzaSyCVC-ZaQ2yuDyF-nbqpVZr5tzj8D_Wff0o" />
        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />
    </application>

</manifest>

我的location_map_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
          android:id="@+id/map"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:name="com.google.android.gms.maps.SupportMapFragment"/>

Answer 1

试试这个..

改变这个..

googleMap =  ((SupportMapFragment) getFragmentManager().findFragmentById(R.id.map)).getMap();

到

googleMap = ((SupportMapFragment) getActivity().getSupportFragmentManager().findFragmentById(R.id.map)).getMap();

Answer 2

Hey Arun问题在

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        initilizeMap(); 
        return inflater.inflate(R.layout.location_map_activity, container, false);
    }

这里是initilizeMap（）;在xml寄存器之前调用，所以只需将其调用到onActivityCreated（）; 而已... 或第二种方式

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view=inflater.inflate(R.layout.location_map_activity, container,false);
                 initilizeMap(); 
            return view;
    }

多数民众赞成......

片段runTimeException，在MapFragment中

2 个答案: