我正在使用Android 2.1和HostTab活动，但是当我编译时，我的应用程序崩溃了
错误"java.lang.NullPointerException"。我不确定，但我猜HostTab有Android 2.1问题需要帮助，有人可以查看我的代码吗？ TY
我的日志是
08-17 19:54:08.025: D/ddm-heap(215): Got feature list request
08-17 19:54:08.035: D/AndroidRuntime(215): Shutting down VM
08-17 19:54:08.035: W/dalvikvm(215): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
08-17 19:54:08.035: E/AndroidRuntime(215): Uncaught handler: thread main exiting due to uncaught exception
08-17 19:54:08.035: E/AndroidRuntime(215): java.lang.RuntimeException: Unable to start activity ComponentInfo{utec.academico/utec.academico.Academico}: java.lang.NullPointerException
08-17 19:54:08.035: E/AndroidRuntime(215): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496)
08-17 19:54:08.035: E/AndroidRuntime(215): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512)
08-17 19:54:08.035: E/AndroidRuntime(215): at android.app.ActivityThread.access$2200(ActivityThread.java:119)
08-17 19:54:08.035: E/AndroidRuntime(215): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863)
08-17 19:54:08.035: E/AndroidRuntime(215): at android.os.Handler.dispatchMessage(Handler.java:99)
08-17 19:54:08.035: E/AndroidRuntime(215): at android.os.Looper.loop(Looper.java:123)
08-17 19:54:08.035: E/AndroidRuntime(215): at android.app.ActivityThread.main(ActivityThread.java:4363)
08-17 19:54:08.035: E/AndroidRuntime(215): at java.lang.reflect.Method.invokeNative(Native Method)
08-17 19:54:08.035: E/AndroidRuntime(215): at java.lang.reflect.Method.invoke(Method.java:521)
08-17 19:54:08.035: E/AndroidRuntime(215): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-17 19:54:08.035: E/AndroidRuntime(215): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-17 19:54:08.035: E/AndroidRuntime(215): at dalvik.system.NativeStart.main(Native Method)
08-17 19:54:08.035: E/AndroidRuntime(215): Caused by: java.lang.NullPointerException
08-17 19:54:08.035: E/AndroidRuntime(215): at utec.academico.Academico.onCreate(Academico.java:28)
08-17 19:54:08.035: E/AndroidRuntime(215): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-17 19:54:08.035: E/AndroidRuntime(215): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
08-17 19:54:08.035: E/AndroidRuntime(215): ... 11 more
08-17 19:54:08.055: I/dalvikvm(215): threadid=7: reacting to signal 3
08-17 19:54:08.055: E/dalvikvm(215): Unable to open stack trace file '/data/anr/traces.txt': Permission denied
08-17 19:54:09.306: I/Process(215): Sending signal. PID: 215 SIG: 9
我的清单是：
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="utec.academico"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="7"
android:targetSdkVersion="15" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".Academico">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".Login"></activity>
<activity android:name=".Horario"></activity>
<activity android:name=".Asistencia"></activity>
<activity android:name=".Notas"></activity>
<activity android:name=".DetalleNotas"></activity>
<activity android:name=".Record"></activity>
</application>
我的主要Hosttab类
public class Academico extends TabActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.academico);
TabHost tabHost=getTabHost(); //Creamos el tabhost de la actividad
tabHost.setup();
TabHost.TabSpec spec; //Creamos el recurso para la propiedad de la pestaña
Intent intent; //intent para abrir la pestaña
Resources res= getResources();//Obtenemos los recursos
//Establecemos el recurso de color para todos los tabs
tabHost.getTabWidget().getChildAt(0).setBackgroundColor(Color.BLACK);
//Se crea el intent para abrir la actividad, configuramos y cargamos el tab en el contenedor tabhost
intent = new Intent().setClass(this, Horario.class);
spec = tabHost.newTabSpec("Horario").setContent(intent).setIndicator("Horario",res.getDrawable(R.drawable.horario));
tabHost.addTab(spec);
intent = new Intent().setClass(this, Notas.class);
spec = tabHost.newTabSpec("Notas").setContent(intent).setIndicator(" Notas ");
tabHost.addTab(spec);
intent = new Intent().setClass(this, Asistencia.class);
spec = tabHost.newTabSpec("Asistencia").setContent(intent).setIndicator("Asistencia",res.getDrawable(R.drawable.asistencia));
tabHost.addTab(spec);
intent = new Intent().setClass(this, Record.class);
spec = tabHost.newTabSpec("Record").setContent(intent).setIndicator(" Record Académico ");
tabHost.addTab(spec);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.academico, menu);
return true;
}
}
然后我的HostTab xml是
<TabHost
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="5dp"
android:layout_weight="1">
</FrameLayout>
<TabWidget
android:id="@android:id/tabs"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_weight="0"
android:layout_marginBottom="-4dp">
</TabWidget>
</LinearLayout>
答案 0 :(得分：1)
我猜问题出在
tabHost.getTabWidget().getChildAt(0).setBackgroundColor(Color.BLACK);
将其移至Oncreate
的末尾