所以我得到了这个片段，我正在初始化这个Linearlayout：
Public class EventFragment extends Fragment {
......
LinearLayout linearProgress;
.....
}
然后我创建我的观点：
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.event,
container, false);
// Check for an open session
Session session = Session.getActiveSession();
if (session != null && session.isOpened()) {
// Get the user's data
ShowEventsFromFQL();
}
return view;
}
正如您所见，我启动了我的方法ShowEventFromFQL：
这只是一个FQL请求，但在我执行该请求之前，我会显示我的进度条：
public void ShowEventsFromFQL(){
// Check for an open session
Session session = Session.getActiveSession();
if (session != null && session.isOpened()) {
//Progressbar active
linearProgress = (LinearLayout) getView().findViewById(R.id.linProgress);
linearProgress.setVisibility(View.VISIBLE);
.........
现在一切都很好。但如果我点击我的后退按钮并再次启动应用程序，我会收到此错误：
11-20 22:50:24.097: E/SpannableStringBuilder(11611): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
11-20 22:50:24.097: E/SpannableStringBuilder(11611): SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
11-20 23:00:05.855: E/AndroidRuntime(11611): FATAL EXCEPTION: main
11-20 23:00:05.855: E/AndroidRuntime(11611): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.laurenswuyts.witpa/com.laurenswuyts.witpa.MainActivity}: android.view.InflateException: Binary XML file line #8: Error inflating class fragment
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2121)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2146)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.ActivityThread.access$700(ActivityThread.java:140)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1238)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.os.Handler.dispatchMessage(Handler.java:99)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.os.Looper.loop(Looper.java:137)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.ActivityThread.main(ActivityThread.java:4944)
11-20 23:00:05.855: E/AndroidRuntime(11611): at java.lang.reflect.Method.invokeNative(Native Method)
11-20 23:00:05.855: E/AndroidRuntime(11611): at java.lang.reflect.Method.invoke(Method.java:511)
11-20 23:00:05.855: E/AndroidRuntime(11611): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
11-20 23:00:05.855: E/AndroidRuntime(11611): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
11-20 23:00:05.855: E/AndroidRuntime(11611): at dalvik.system.NativeStart.main(Native Method)
11-20 23:00:05.855: E/AndroidRuntime(11611): Caused by: android.view.InflateException: Binary XML file line #8: Error inflating class fragment
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:710)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.view.LayoutInflater.rInflate(LayoutInflater.java:752)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.view.LayoutInflater.inflate(LayoutInflater.java:495)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
11-20 23:00:05.855: E/AndroidRuntime(11611): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:318)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.Activity.setContentView(Activity.java:1924)
11-20 23:00:05.855: E/AndroidRuntime(11611): at com.laurenswuyts.witpa.MainActivity.onCreate(MainActivity.java:48)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.Activity.performCreate(Activity.java:5188)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2085)
11-20 23:00:05.855: E/AndroidRuntime(11611): ... 11 more
11-20 23:00:05.855: E/AndroidRuntime(11611): Caused by: java.lang.NullPointerException
11-20 23:00:05.855: E/AndroidRuntime(11611): at com.laurenswuyts.witpa.EventFragment.ShowEventsFromFQL(EventFragment.java:76)
11-20 23:00:05.855: E/AndroidRuntime(11611): at com.laurenswuyts.witpa.EventFragment.onCreateView(EventFragment.java:54)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:846)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1061)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.support.v4.app.FragmentManagerImpl.addFragment(FragmentManager.java:1160)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.support.v4.app.FragmentActivity.onCreateView(FragmentActivity.java:272)
11-20 23:00:05.855: E/AndroidRuntime(11611): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:682)
11-20 23:00:05.855: E/AndroidRuntime(11611): ... 21 more
EventFragment.java:76是我的ShowEventFrom FQL中// Progressbar活动后的一行
这是我的XML布局：
<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"
android:orientation="vertical">
<LinearLayout
android:id="@+id/linProgress"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center"
android:orientation="vertical"
android:visibility="gone" >
<ProgressBar
android:id="@+id/spinnerProgressBar"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center">
</ProgressBar>
</LinearLayout>
<ListView
android:id="@+id/lvEvent"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:divider="@null"
android:dividerHeight="0dp"/>
</RelativeLayout>
任何人都可以帮助我..
答案 0 :(得分：1)
试试这个..删除onCreateView中的超级并运行它。
@Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.event,
container, false);
// Check for an open session
Session session = Session.getActiveSession();
if (session != null && session.isOpened()) {
// Get the user's data
ShowEventsFromFQL();
}
return view;
}
就像你必须在onCreateView
linearProgress = (LinearLayout) getView().findViewById(R.id.linProgress);
但你需要改变如下。
linearProgress = (LinearLayout) view.findViewById(R.id.linProgress);
view是此活动的父视图，因此请像上面的代码一样使用