Android 后台管理：仅在所有者'；s初始化阶段
我在MainActivity中使用底部导航栏来处理一些片段。这是用于在它们之间切换的代码：Android 后台管理：仅在所有者'；s初始化阶段,android,android-fragments,kotlin,back-stack,fragmentmanager,Android,Android Fragments,Kotlin,Back Stack,Fragmentmanager,我在MainActivity中使用底部导航栏来处理一些片段。这是用于在它们之间切换的代码： private val mOnNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item -> if (item.isChecked && supportFragmentManager.findFragmentById(R.id.ac
private val mOnNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
if (item.isChecked &&
supportFragmentManager.findFragmentById(R.id.act_main_fragment_container) != null
)
return@OnNavigationItemSelectedListener false
val fragment =
when (item.itemId) {
R.id.navigation_home -> fragments[0]
R.id.navigation_bookings -> fragments[1]
R.id.navigation_messages -> fragments[2]
R.id.navigation_dashboard -> fragments[3]
R.id.navigation_profile -> fragments[4]
else -> fragments[0]
}
this replaceWithNoBackStack fragment
return@OnNavigationItemSelectedListener true
}
supportFragmentManager
?.beginTransaction()
?.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN)
?.replace(containerId, fragment)
?.commit()
androidx.appcompat:appcompat:1.0.2ex）appcompat:1.1.0-beta01或1.0.2
我认为当目标片段被重用（onPause onResume）时，保存状态时会出现错误。我将实现更改为androidx的api。appcompat:appcompat:1.0.2，它对我有效，因为版本1.0.0没有检查状态，所以它不会引发异常， 但是版本1.1.0更改了源代码，因此抛出了异常 这是片段版本-1.1.0源代码，它将调用方法
performRestore void performCreate(Bundle savedInstanceState) {
if (mChildFragmentManager != null) {
mChildFragmentManager.noteStateNotSaved();
}
mState = CREATED;
mCalled = false;
mSavedStateRegistryController.performRestore(savedInstanceState);
onCreate(savedInstanceState);
mIsCreated = true;
if (!mCalled) {
throw new SuperNotCalledException("Fragment " + this
+ " did not call through to super.onCreate()");
}
mLifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE);
}
/**
the exception
**/
public void performRestore(@Nullable Bundle savedState) {
Lifecycle lifecycle = mOwner.getLifecycle();
if (lifecycle.getCurrentState() != Lifecycle.State.INITIALIZED) {
throw new IllegalStateException("Restarter must be created only during "
+ "owner's initialization stage");
}
lifecycle.addObserver(new Recreator(mOwner));
mRegistry.performRestore(lifecycle, savedState);
}
performRestorevoid performCreate(Bundle savedInstanceState) {
if (mChildFragmentManager != null) {
mChildFragmentManager.noteStateNotSaved();
}
mState = CREATED;
mCalled = false;
onCreate(savedInstanceState);
mIsCreated = true;
if (!mCalled) {
throw new SuperNotCalledException("Fragment " + this
+ " did not call through to super.onCreate()");
}
mLifecycleRegistry.handleLifecycleEvent(Lifecycle.Event.ON_CREATE);
}
第一个解决方案是拆分交易。
因为我们总是使用
replaceremoveaddFragmentTransaction ft = manager.beginTransaction();
Fragment prev = manager.findFragmentByTag(tag);
if (prev != null) {
//commit immediately
ft.remove(prev).commitAllowingStateLoss();
}
FragmentTransaction addTransaction = manager.beginTransaction();
addTransaction.addToBackStack(null);
addTransaction.add(layoutId, fragment,
tag).commitAllowingStateLoss();
第二种解决方案是提前检查状态。 我们可以按照源代码，提前检查状态
FragmentTransaction ft = manager.beginTransaction();
Fragment prev = manager.findFragmentByTag(tag);
if (prev != null) {
if (prev.getLifecycle().getCurrentState() != Lifecycle.State.INITIALIZED) {
return;
}
ft.remove(prev);
}
代码更改代码，它将无效。此错误似乎可以通过使用androidx解决。appcompat:appcomat:1.1.0-rc01和androidx.fragment:fragment:1.1.0-rc03
我也有同样的问题
val fragment = Account.activityAfterLogin
val ft = activity?.getSupportFragmentManager()?.beginTransaction()
//error
ft?.setCustomAnimations(android.R.anim.slide_in_left,android.R.anim.slide_out_right)0
ft?.replace(R.id.framelayout_account,fragment)
ft?.commit()
ft？.setCustomAnimations（）ft？.AddToBackStack（null）动画工作正常，没有崩溃。我在使用
setCustomAnimationssetCustomAnimations编辑：另一种方法是将片段添加到backstack。如果可以的话，我在BottomNavigationView和setCustomAnimations中遇到了相同的问题，基本上是通过在片段之间快速切换，您可能会在前一个片段未完成时启动片段事务，然后崩溃
public void toggleNavigationBarItems(boolean enabled) {
Menu navMenu = navigationView.getMenu();
for (int i = 0; i < navMenu.size(); ++i) {
navMenu.getItem(i).setEnabled(enabled);
}
}
@Nullable
@Override
public Animator onCreateAnimator(int transit, boolean enter, int nextAnim) {
if(enter){ // check the note below
Animator animator = AnimatorInflater.loadAnimator(getContext(), nextAnim);
animator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
myActivity.toggleNavigationBarItems(true)
}
});
return animator;
}
return super.onCreateAnimator(transit, enter, nextAnim);
}
if (getChildFragmentManager().getBackStackEntryCount() > 0) {
getChildFragmentManager().popBackStack();
}
FragmentTransaction addTransaction = getChildFragmentManager().beginTransaction();
addTransaction.setCustomAnimations(R.animator.fragment_fade_in, R.animator.fragment_fade_out);
addTransaction.addToBackStack(null);
addTransaction.add(R.id.frame, fragment, fragment.getClass().getName()).commitAllowingStateLoss();
public void addFragment(int contentFrameId, Fragment fragment, Bundle param, boolean addToStack) {
try {
if (!fragment.isAdded()) {
if (param != null) {
fragment.setArguments(param);
}
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction()
.add(contentFrameId, fragment)
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
if (addToStack)
fragmentTransaction.addToBackStack(fragment.getClass().toString());
fragmentTransaction.commit();
}
} catch (IllegalStateException e) {
handleError(e.getMessage());
} catch (Exception e) {
handleError(e.getMessage());
}
}
public synchronized void addFragment(int contentFrameId, Fragment fragment, Bundle param, boolean addToStack) {
try {
if (!fragment.isAdded()) {
if (param != null) {
fragment.setArguments(param);
}
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction()
.add(contentFrameId, fragment)
.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
if (addToStack)
fragmentTransaction.addToBackStack(fragment.getClass().toString());
fragmentTransaction.commit();
}
} catch (IllegalStateException e) {
handleError(e.getMessage());
} catch (Exception e) {
handleError(e.getMessage());
}
}