AlertFragment 有问题，当您第一次运行该应用程序时显示良好，但当您旋转设备(方向已更改)时应用程序崩溃。
架构:MainActivity --> ScheduledRecListFragment --> AlertFragment
MainActivity(简化摘录):
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState); // < -- line 28
setContentView(R.layout.activity_main);
fragmentManager = getFragmentManager();
fragmentTransaction = fragmentManager.beginTransaction();
ScheduledRecListFragment fragment = new ScheduledRecListFragment();
if(getFragmentManager().findFragmentByTag("RecListFrag") == null) {
fragmentTransaction.add(R.id.fragment_container, fragment, "RecListFrag");
fragmentTransaction.commit();
}
}
ScheduledRecListFragment(简化摘录):
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.scheduled_rec_list_fragment, container, false);
lv = (ListView) v.findViewById(R.id.listViewRecs);
// ...
if(db.selectAllRecords().getCount() == 0 ) {
new AlertFragment(getString(R.string.alert), getString(R.string.no_recs)).show(getFragmentManager(), "MyDialog");
}
// ...
return v;
}
警报 fragment :
class AlertFragment extends DialogFragment {
String title;
String message;
public AlertFragment(String title, String message) {
this.title = title;
this.message = message;
}
public AlertFragment() {
}
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(getActivity());
alertDialogBuilder.setTitle(title);
alertDialogBuilder.setMessage(message);
//null should be your on click listener
alertDialogBuilder.setNegativeButton("Dismiss", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
return alertDialogBuilder.create();
}
}
日志:
12-30 12:35:27.421 11871-11871/com.app.example E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.app.example/com.app.example.MainActivity}: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.app.example.AlertFragment: make sure class name exists, is public, and has an empty constructor that is public
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2205)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2255)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3727)
at android.app.ActivityThread.access$700(ActivityThread.java:146)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1246)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5171)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:797)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:564)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.app.example.AlertFragment: make sure class name exists, is public, and has an empty constructor that is public
at android.app.Fragment.instantiate(Fragment.java:600)
at android.app.FragmentState.instantiate(Fragment.java:97)
at android.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1747)
at android.app.Activity.onCreate(Activity.java:922)
at com.app.example.MainActivity.onCreate(MainActivity.java:28)
at android.app.Activity.performCreate(Activity.java:5200)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2169)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2255)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3727)
at android.app.ActivityThread.access$700(ActivityThread.java:146)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1246)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5171)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:797)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:564)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalAccessException: access to class not allowed
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1319)
at android.app.Fragment.instantiate(Fragment.java:585)
at android.app.FragmentState.instantiate(Fragment.java:97)
at android.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1747)
at android.app.Activity.onCreate(Activity.java:922)
at com.app.example.MainActivity.onCreate(MainActivity.java:28)
at android.app.Activity.performCreate(Activity.java:5200)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2169)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2255)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:3727)
at android.app.ActivityThread.access$700(ActivityThread.java:146)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1246)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:5171)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:797)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:564)
at dalvik.system.NativeStart.main(Native Method)
最佳答案
好的，我找到了...解决方案是将 setRetainInstance(true) 放在 Dialog 的 onCreateDialog() 中方法。
关于android - DialogFragment 在方向更改时使应用程序崩溃，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20839138/