我正在开发安卓纸牌游戏,我正在使用 DialogFragment 渲染一些图像并告诉玩家对对手采取行动。
下面的代码被执行了很多次,完全没有错误,但是在假设 5 到 10 次之后发生了以下异常。
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)
上面的异常说明里面 android.app.DialogFragment mDialog 在该行为空 mDialog.setContentView(view);
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());
我正在从这里实例化对话框 错误发生在
boolean executePendingTransactions = fm.executePendingTransactions(); 我按照相关帖子中的建议添加了它以解决问题。 在添加此语句之前,错误发生时没有说明我的包下的任何类
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");
}
});
为了在我的对话框中进行调试,此方法已被重写
@Override
public void onActivityCreated(Bundle savedInstanceState) {
MyLog.i(TAG, "onActivityCreated: ----------------------------------");
super.onActivityCreated(savedInstanceState);
}
最佳答案
通过执行以下操作不再显示此异常:
我将所有组件声明为字段成员而不是局部变量
public class RentCardDialog extends DialogFragment { private static final String TAG = "RentCardDialog"; private TextView title1; private TextView title2; private TextView title1TxtView; private TextView title2TxtView;
然后只需在 onCreateView 中初始化它们,如下所示
@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);
最后,我添加了我想要的任何 fragment ,并按如下方式在 onActivityCreated 中构建所有对话框组件
@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); } });
在对话框的业务工作在 onCreateView 内部之前,所以问题可能是某些组件尚未真正加载,特别是 fragment ,因此它会触发该异常,
现在通过执行以下操作,它可以完美地工作。
关于java - android DialogFragment mDialog 为空导致异常,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44034789/