Java – Android dialogfragment mdialog is null, causing an exception
I'm developing an Android card game. I'm using dialogfragment. I present some images and tell players to take action against their opponents
The following code is executed many times without error, but let's say that the following exception occurs after 5 to 10 times
E/AndroidRuntime: FATAL EXCEPTION: mainProcess: com.arabdealgame.arabdealgame,PID: 8359
java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.Dialog.setOwnerActivity(android.app.Activity)' on a null object reference
at android.app.DialogFragment.onActivityCreated(DialogFragment.java:482)
at com.arabdealgame.activities.dialog.RentCardDialog.onActivityCreated(RentCardDialog.java:342)
at android.app.Fragment.performActivityCreated(Fragment.java:2362)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1014)
at android.app.FragmentManagerImpl.moveToState(FragmentManager.java:1171)
at android.app.BackStackRecord.run(BackStackRecord.java:815)
at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1578)
at android.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:563)
at com.arabdealgame.bo.Actions.RentActionCard$5.run(RentActionCard.java:315)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
The above exception is to tell Android app. Dialogfragment mdialog is null mdialog in this behavior Setcontentview;
android. app. DialogFragment
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (!mShowsDialog) {
return;
}
View view = getView();
if (view != null) {
if (view.getParent() != null) {
throw new IllegalStateException("DialogFragment can not be attached to a container view");
}
mDialog.setContentView(view);
}
mDialog.setOwnerActivity(getActivity());
I instantiate the dialog box from here. The error occurred in
boolean executePendingTransactions = fm. executePendingTransactions(); I suggest adding in related posts to solve the problem Before adding this statement, no classes under my package will be declared when an error occurs
RentActionCard. java
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
MyLog.i(TAG,"run: --------------------------1");
FragmentManager fm = getActivity().getFragmentManager();
MyLog.i(TAG,"run: --------------------------2");
RentCardDialog rentCardDialog = new RentCardDialog();
MyLog.i(TAG,"run: --------------------------3");
if (!GameInfo.getCurrentPlayer().isUser()) {
MyLog.i(TAG,"run: --------------------------4");
rentCardDialog.setAgainstUser(true);
}
rentCardDialog.show(fm,"ccc");
boolean executePendingTransactions = fm.executePendingTransactions();
MyLog.d(TAG,"RentActionCard - executePendingTransactions : " + executePendingTransactions);
MyLog.i(TAG,"run: --------------------------5");
}
});
In my dialog box, this method has been overridden for debugging purposes
@Override
public void onActivityCreated(Bundle savedInstanceState) {
MyLog.i(TAG,"onActivityCreated: ----------------------------------");
super.onActivityCreated(savedInstanceState);
}
Solution
Do the following to not show this exception again:
>I declare all components as field members rather than local variables
public class RentCardDialog extends DialogFragment {
private static final String TAG = "RentCardDialog";
private TextView title1;
private TextView title2;
private TextView title1TxtView;
private TextView title2TxtView;
>Then simply initialize them in oncreateview, as shown below
@Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.dialog_rent_card,container,false);
title1 = (TextView) rootView.findViewById(R.id.rent_card_dialog_title1);
title2 = (TextView) rootView.findViewById(R.id.rent_card_dialog_title2);
title1TxtView = (TextView) rootView.findViewById(R.id.rent_card_dialog_title1);
title2TxtView = (TextView) rootView.findViewById(R.id.rent_card_dialog_title2);
>Finally, I added any fragment I wanted and built all the dialog components in onactivitycreated, as shown below
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState); // Will Now complete and not crash
try {
buildUserOptions();
MyLog.i(TAG,"onCreateView: ---------------------------3");
player2Fragment.setExecuteCallback(new CallbackInterface() {
@Override
public void execute() {
player2Fragment.refreshPlayerData(player2);
}
});
Before the business work of the dialog box enters oncreateview, the problem may be that some components are not really loaded, especially fragments, so it triggers the exception,
Now complete the work in the following ways