我正在开发我的项目，其中我需要谷歌地图..并且我使用的代码与我之前的应用程序中使用的代码相同。但这次当我打开此 Activity 时，我遇到了空指针异常。
这是我的map.java 文件:-
public class map extends FragmentActivity{
GoogleMap map;
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.map);
Bundle b=getIntent().getExtras();
String lat[]=b.getStringArray("lat");
String log[]=b.getStringArray("log");
String name[]=b.getStringArray("name");
FragmentManager fmanager = getSupportFragmentManager();
Fragment fragment = fmanager.findFragmentById(R.id.map);
SupportMapFragment supportmapfragment = (SupportMapFragment)fragment;
map = supportmapfragment.getMap();
LatLng place[]=new LatLng[lat.length];
for(int i=0;i<place.length;i++)
{
if(lat[i].equals(""))
lat[i]="0.0";
if(log[i].equals(""))
log[i]="0.0";
place[i]=new LatLng(Double.parseDouble(lat[i]),Double.parseDouble(log[i]));
}
Marker marker[]=new Marker[lat.length];
for(int i=0;i<lat.length;i++)
{
marker[i] = map.addMarker(new MarkerOptions().position(place[i]).title(name[i]));
}
// Move the camera instantly to hamburg with a zoom of 15.
for(int i=0;i<place.length;i++)
map.moveCamera(CameraUpdateFactory.newLatLngZoom(place[i], 15));
// Zoom in, animating the camera.
map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null);
}
}
我的 XML 文件:-
<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=".map" >
<fragment
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
class="com.google.android.gms.maps.SupportMapFragment" />
</RelativeLayout>
我的 list 文件:-
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.pumaguard.pumaguard"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.DISABLE_KEYGUARD" />
<permission
android:name="com.pumaguard.pumaguard.permission.MAPS_RECEIVE"
android:protectionLevel="signature" />
<uses-permission android:name="com.pumaguard.pumaguard.locationapi.maps.permission.MAPS_RECEIVE" />
<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-feature
android:glEsVersion="0x00020000"
android:required="true" />
<application
android:allowBackup="true"
android:icon="@drawable/icon"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.pumaguard.pumaguard.splash"
android:label="@string/app_name"
android:screenOrientation="landscape"
android:theme="@android:style/Theme.NoTitleBar" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".MainActivity"
android:screenOrientation="landscape"
android:theme="@android:style/Theme.NoTitleBar" >
</activity>
<activity
android:name=".newactivity"
android:screenOrientation="landscape"
android:theme="@android:style/Theme.NoTitleBar" >
</activity>
<activity
android:name=".map"
android:screenOrientation="landscape"
android:theme="@android:style/Theme.NoTitleBar" >
</activity>
<meta-data
android:name="com.google.android.maps.v2.API_KEY"
android:value="AIzaSyBd7gzE3nKLfbRO5XfDoOtaJc5q1C9RTiA" />
<meta-data
android:name="com.google.android.gms.version"
android:value="@integer/google_play_services_version" />
</application>
</manifest>
logcat 错误:-
01-24 22:56:01.636: E/AndroidRuntime(835): FATAL EXCEPTION: main
01-24 22:56:01.636: E/AndroidRuntime(835): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.pumaguard.pumaguard/com.pumaguard.pumaguard.map}: java.lang.NullPointerException
01-24 22:56:01.636: E/AndroidRuntime(835): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.app.ActivityThread.access$600(ActivityThread.java:141)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.os.Handler.dispatchMessage(Handler.java:99)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.os.Looper.loop(Looper.java:137)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.app.ActivityThread.main(ActivityThread.java:5103)
01-24 22:56:01.636: E/AndroidRuntime(835): at java.lang.reflect.Method.invokeNative(Native Method)
01-24 22:56:01.636: E/AndroidRuntime(835): at java.lang.reflect.Method.invoke(Method.java:525)
01-24 22:56:01.636: E/AndroidRuntime(835): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
01-24 22:56:01.636: E/AndroidRuntime(835): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
01-24 22:56:01.636: E/AndroidRuntime(835): at dalvik.system.NativeStart.main(Native Method)
01-24 22:56:01.636: E/AndroidRuntime(835): Caused by: java.lang.NullPointerException
01-24 22:56:01.636: E/AndroidRuntime(835): at com.pumaguard.pumaguard.map.onCreate(map.java:62)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.app.Activity.performCreate(Activity.java:5133)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
01-24 22:56:01.636: E/AndroidRuntime(835): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
01-24 22:56:01.636: E/AndroidRuntime(835): ... 11 more
所以，这是我的代码，请帮助我解决我的问题。 谢谢。
最佳答案
首先不要向所有人展示您的 API key
其次，您应该为每个应用程序生成新的 API key
第三，你可以使用
SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
googleMap = fm.getMap();
而不是
FragmentManager fmanager = getSupportFragmentManager();
Fragment fragment = fmanager.findFragmentById(R.id.map);
SupportMapFragment supportmapfragment = (SupportMapFragment)fragment;
map = supportmapfragment.getMap();
并告诉我们您在哪一行收到错误，并向我们显示该行。
关于java - Android代码中的谷歌地图给出空指针异常，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21346603/