我有几个带有OnItemSelectListeners的AutoCompleteTextViews，因为我希望在选择了一个条目时，焦点转移到下一个文本字段。我已经阅读了相关问题的答案Focus next textview automatically，它让我了解了如何获得下一个可聚焦的项目，但它没有用。
我的OnClickListener：
OnItemClickListener nextListener = new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id){
view.focusSearch(View.FOCUS_RIGHT).requestFocus();
}
};
这会导致应用崩溃。我也尝试过使用findNextFocus的东西，但是也没办法。我错过了什么？任何帮助表示赞赏。
logcat的：
09-05 14:42:36.732: E/AndroidRuntime(10646): FATAL EXCEPTION: main
09-05 14:42:36.732: E/AndroidRuntime(10646): Process: cau.swp.babsi, PID: 10646
09-05 14:42:36.732: E/AndroidRuntime(10646): java.lang.NullPointerException
09-05 14:42:36.732: E/AndroidRuntime(10646): at cau.swp.babsi.gui.AntibioticActivity$1.onItemClick(AntibioticActivity.java:62)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.widget.AutoCompleteTextView.performCompletion(AutoCompleteTextView.java:902)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.widget.AutoCompleteTextView.access$500(AutoCompleteTextView.java:91)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.widget.AutoCompleteTextView$DropDownItemClickListener.onItemClick(AutoCompleteTextView.java:1192)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.widget.AdapterView.performItemClick(AdapterView.java:299)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.widget.AbsListView.performItemClick(AbsListView.java:1113)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.widget.AbsListView$PerformClick.run(AbsListView.java:2911)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.widget.AbsListView$3.run(AbsListView.java:3645)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.os.Handler.handleCallback(Handler.java:733)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.os.Handler.dispatchMessage(Handler.java:95)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.os.Looper.loop(Looper.java:136)
09-05 14:42:36.732: E/AndroidRuntime(10646): at android.app.ActivityThread.main(ActivityThread.java:5001)
09-05 14:42:36.732: E/AndroidRuntime(10646): at java.lang.reflect.Method.invokeNative(Native Method)
09-05 14:42:36.732: E/AndroidRuntime(10646): at java.lang.reflect.Method.invoke(Method.java:515)
09-05 14:42:36.732: E/AndroidRuntime(10646): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
09-05 14:42:36.732: E/AndroidRuntime(10646): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
09-05 14:42:36.732: E/AndroidRuntime(10646): at dalvik.system.NativeStart.main(Native Method)
09-05 14:42:39.094: E/AndroidRuntime(10710): FATAL EXCEPTION: main
09-05 14:42:39.094: E/AndroidRuntime(10710): Process: cau.swp.babsi, PID: 10710
09-05 14:42:39.094: E/AndroidRuntime(10710): java.lang.RuntimeException: Unable to start activity ComponentInfo{cau.swp.babsi/cau.swp.babsi.gui.ChecklistActivity}: java.lang.NullPointerException
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.app.ActivityThread.access$800(ActivityThread.java:135)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.os.Handler.dispatchMessage(Handler.java:102)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.os.Looper.loop(Looper.java:136)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.app.ActivityThread.main(ActivityThread.java:5001)
09-05 14:42:39.094: E/AndroidRuntime(10710): at java.lang.reflect.Method.invokeNative(Native Method)
09-05 14:42:39.094: E/AndroidRuntime(10710): at java.lang.reflect.Method.invoke(Method.java:515)
09-05 14:42:39.094: E/AndroidRuntime(10710): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
09-05 14:42:39.094: E/AndroidRuntime(10710): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
09-05 14:42:39.094: E/AndroidRuntime(10710): at dalvik.system.NativeStart.main(Native Method)
09-05 14:42:39.094: E/AndroidRuntime(10710): Caused by: java.lang.NullPointerException
09-05 14:42:39.094: E/AndroidRuntime(10710): at cau.swp.babsi.db.DatabaseAdapter.getDiagnosen(DatabaseAdapter.java:306)
09-05 14:42:39.094: E/AndroidRuntime(10710): at cau.swp.babsi.gui.ChecklistActivity$DiagnoseFragment.onCreateView(ChecklistActivity.java:384)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.support.v4.app.Fragment.performCreateView(Fragment.java:1478)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:927)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1086)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1877)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:552)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1171)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.app.Activity.performStart(Activity.java:5241)
09-05 14:42:39.094: E/AndroidRuntime(10710): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2157)
09-05 14:42:39.094: E/AndroidRuntime(10710): ... 11 more