Android 安卓嵌套碎片问题“;java.lang.IllegalStateException:活动已被销毁;
您可能知道,Android支持嵌套片段,也可以通过API级别为17的支持库。因此,基本上我正在尝试将嵌套片段添加到ViewPager的片段中,并熟悉这个新的优秀功能 在第一次应用发布时,一切都按预期运行,即我可以添加子片段、浏览这些片段、处理后堆栈等 但问题是,当我通过单击“上一步”按钮退出应用程序并重新启动应用程序时,我大部分时间都会遇到以下异常,但并非总是如此:Android 安卓嵌套碎片问题“;java.lang.IllegalStateException:活动已被销毁;,android,android-fragments,Android,Android Fragments,您可能知道,Android支持嵌套片段,也可以通过API级别为17的支持库。因此,基本上我正在尝试将嵌套片段添加到ViewPager的片段中,并熟悉这个新的优秀功能 在第一次应用发布时,一切都按预期运行,即我可以添加子片段、浏览这些片段、处理后堆栈等 但问题是,当我通过单击“上一步”按钮退出应用程序并重新启动应用程序时,我大部分时间都会遇到以下异常,但并非总是如此: java.lang.IllegalStateException: Activity has been destroyed
java.lang.IllegalStateException: Activity has been destroyed
at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1342)
at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595)
at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:574)
at com.cnlms.andnestedfragments.ui.fragments.FragWrapper.addChildFragment(FragWrapper.java:145)
at com.cnlms.andnestedfragments.ui.fragments.FragWrapper.onActivityCreated(FragWrapper.java:96)
at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:1468)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:931)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1088)
at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1444)
at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:461)
at android.support.v4.app.FragmentStatePagerAdapter.finishUpdate(FragmentStatePagerAdapter.java:163)
at android.support.v4.view.ViewPager.populate(ViewPager.java:1012)
at android.support.v4.view.ViewPager.populate(ViewPager.java:881)
at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1366)
at android.view.View.measure(View.java:15172)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
at android.view.View.measure(View.java:15172)
at android.widget.LinearLayout.measureVertical(LinearLayout.java:833)
at android.widget.LinearLayout.onMeasure(LinearLayout.java:574)
at android.view.View.measure(View.java:15172)
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4814)
at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2148)
at android.view.View.measure(View.java:15172)
at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:1848)
at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1100)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1273)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:998)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4212)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
at android.view.Choreographer.doCallbacks(Choreographer.java:555)
at android.view.Choreographer.doFrame(Choreographer.java:525)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4745)
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:786)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
at dalvik.system.NativeStart.main(Native Method)
整个项目是可用的
活动是否可以在某个点为空?我的意思是,当我调用getChildFragmentManager()时,活动不应该附加到片段管理器吗?如有任何建议,将不胜感激
有关该应用程序的更多详细信息
ViewPager承载两个片段实例:FragRegular和FragWrapper。第一个只是一个简单无用的片段;第二个FragWrapper充当父片段,即子片段的容器。下面是FragWrapper的布局:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<!--
Adds nested child fragments when clicked
-->
<Button
android:id="@+id/btn_go_deep"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="Go Nesty!"/>
<!--
Nested Fragment Container
-->
<FrameLayout
android:id="@+id/frag_container"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_above="@id/btn_go_deep"/>
</RelativeLayout>
public final class FragWrapper extends BaseFragment {
/**
*
* The Wrapper Fragment that hosts nested child fragments.
*
* First child fragment is added in onActivityCreated() callback
*
* More child fragments can be added at runtime by clicking 'Go Nesty!'
* button.
*
*/
/**
* Holds back stacked fragment tags
*/
private Stack<String> backStack;
/**
* Child Fragment Manager
*/
private FragmentManager fm;
/**
* Fragment Tags
*/
private int fragCount = 1;
private static FragWrapper instance;
public static FragWrapper getInstance() {
if (instance == null) {
instance = new FragWrapper();
}
return instance;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.frag_wrapper, container, false);
view.findViewById(R.id.btn_go_deep).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
/**
* Adds nested child fragments
*/
fragCount+=1;
addChildFragment(
FragChild.newInstance(fragCount),
String.valueOf(fragCount),
true
);
}
});
return view;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
/**
* Add Initial Fragment
*/
addChildFragment(
FragChild.newInstance(fragCount),
String.valueOf(fragCount),
false
);
}
private void addChildFragment(final Fragment fragment, final String fragmentTag, final boolean addToBackStack) {
/**
* initialize child fragment manager
*/
if (fm == null) fm = getChildFragmentManager();
/**
* Starts a new transaction
*/
FragmentTransaction ft = fm.beginTransaction();
/**
* Hide lastly added fragment
*/
if (backStack != null && !backStack.isEmpty()) {
ft.hide(fm.findFragmentByTag(backStack.peek()));
}
/**
* Add new fragment
*/
ft.add(R.id.frag_container, fragment, fragmentTag );
/**
* Add to back stack
*/
if (addToBackStack) {
ft.addToBackStack(null);
}
/**
* Commit transaction
*/
ft.commit();
/**
* Save fragment tag
*/
if (backStack == null) backStack = new Stack<String>();
backStack.push(fragmentTag);
}
public boolean popFragment() {
/**
* Allow this fragment to consume the back button click
*/
if (backStack != null && !backStack.isEmpty()) {
backStack.pop();
fragCount-=1;
}
return fm != null && fm.popBackStackImmediate();
}
@Override
public boolean backPressed() {
return popFragment();
}
}
因此,基本上第一个子片段被添加到FragWrapper的onActivityCreated()回调方法中的FragWrapper中,随后的子片段在运行时添加,通过单击按钮触发。下面是FragWrapper类的外观:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<!--
Adds nested child fragments when clicked
-->
<Button
android:id="@+id/btn_go_deep"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:text="Go Nesty!"/>
<!--
Nested Fragment Container
-->
<FrameLayout
android:id="@+id/frag_container"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="match_parent"
android:layout_above="@id/btn_go_deep"/>
</RelativeLayout>
public final class FragWrapper extends BaseFragment {
/**
*
* The Wrapper Fragment that hosts nested child fragments.
*
* First child fragment is added in onActivityCreated() callback
*
* More child fragments can be added at runtime by clicking 'Go Nesty!'
* button.
*
*/
/**
* Holds back stacked fragment tags
*/
private Stack<String> backStack;
/**
* Child Fragment Manager
*/
private FragmentManager fm;
/**
* Fragment Tags
*/
private int fragCount = 1;
private static FragWrapper instance;
public static FragWrapper getInstance() {
if (instance == null) {
instance = new FragWrapper();
}
return instance;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.frag_wrapper, container, false);
view.findViewById(R.id.btn_go_deep).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
/**
* Adds nested child fragments
*/
fragCount+=1;
addChildFragment(
FragChild.newInstance(fragCount),
String.valueOf(fragCount),
true
);
}
});
return view;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
/**
* Add Initial Fragment
*/
addChildFragment(
FragChild.newInstance(fragCount),
String.valueOf(fragCount),
false
);
}
private void addChildFragment(final Fragment fragment, final String fragmentTag, final boolean addToBackStack) {
/**
* initialize child fragment manager
*/
if (fm == null) fm = getChildFragmentManager();
/**
* Starts a new transaction
*/
FragmentTransaction ft = fm.beginTransaction();
/**
* Hide lastly added fragment
*/
if (backStack != null && !backStack.isEmpty()) {
ft.hide(fm.findFragmentByTag(backStack.peek()));
}
/**
* Add new fragment
*/
ft.add(R.id.frag_container, fragment, fragmentTag );
/**
* Add to back stack
*/
if (addToBackStack) {
ft.addToBackStack(null);
}
/**
* Commit transaction
*/
ft.commit();
/**
* Save fragment tag
*/
if (backStack == null) backStack = new Stack<String>();
backStack.push(fragmentTag);
}
public boolean popFragment() {
/**
* Allow this fragment to consume the back button click
*/
if (backStack != null && !backStack.isEmpty()) {
backStack.pop();
fragCount-=1;
}
return fm != null && fm.popBackStackImmediate();
}
@Override
public boolean backPressed() {
return popFragment();
}
}
public final类FragWrapper扩展BaseFragment{
/**
*
*承载嵌套子片段的包装器片段。
*
*第一个子片段添加到onActivityCreated()回调中
*
*通过单击“Go Nesty!”可以在运行时添加更多子片段
*按钮。
*
*/
/**
*保留堆叠的片段标记
*/
私有堆栈回退;
/**
*子片段管理器
*/
私人碎片管理器fm;
/**
*片段标签
*/
私有整数fragCount=1;
私有静态FragWrapper实例;
公共静态FragWrapper getInstance(){
if(实例==null){
实例=新FragWrapper();
}
返回实例;
}
@凌驾
CreateView上的公共视图(布局、充气机、视图组容器、捆绑包保存状态){
视图=充气机。充气(R.layout.frag_包装,容器,假);
view.findviewbyd(R.id.btn\u go\u deep).setOnClickListener(新视图.OnClickListener(){
@凌驾
公共void onClick(视图v){
/**
*添加嵌套的子片段
*/
fragCount+=1;
addChildFragment(
FragChild.newInstance(fragCount),
字符串.valueOf(fragCount),
真的
);
}
});
返回视图;
}
@凌驾
已创建ActivityState上的公共无效(Bundle savedInstanceState){
super.onActivityCreated(savedInstanceState);
/**
*添加初始片段
*/
addChildFragment(
FragChild.newInstance(fragCount),
字符串.valueOf(fragCount),
假的
);
}
私有void addChildFragment(最终片段片段、最终字符串fragmentTag、最终布尔addToBackStack){
/**
*初始化子片段管理器
*/
如果(fm==null)fm=getChildFragmentManager();
/**
*启动新事务
*/
FragmentTransaction ft=fm.beginTransaction();
/**
*隐藏最后添加的片段
*/
if(backStack!=null&&!backStack.isEmpty()){
ft.hide(fm.findFragmentByTag(backStack.peek());
}
/**
*添加新片段
*/
ft.add(R.id.fragment_容器、碎片、碎片标签);
/**
*添加到后堆栈
*/
if(addToBackStack){
ft.addToBackStack(空);
}
/**
*提交事务
*/
ft.commit();
/**
*保存片段标记
*/
如果(backStack==null)backStack=newstack();
后推(碎片标签);
}
公共布尔值片段(){
/**
*允许此片段使用“后退”按钮单击
*/
if(backStack!=null&&!backStack.isEmpty()){
backback.pop();
fragCount-=1;
}
返回fm!=null&&fm.popbackackimmediate();
}
@凌驾
public boolean backPressed(){
返回popFragment();
}
}
有人发布了另一个类似的问题,该问题是由于ChildFragmentManager中的一个错误造成的。基本上,当子FragmentManager与活动分离时,它的内部状态会被破坏。查看原始答案是否有理由通过保持静态引用(您确实不应该这样做)将您的FragRapper
设置为单例?我将其作为单例使用,以便稍后在FragmentActivity中访问它。onBackPressed()并允许这些片段使用背压。您的代码不正确,在某些情况下会出错。我已经将您的示例项目修改为应该可以工作的项目,您可以在这里找到它。请查看。@Luksprog感谢您的评论和努力。您的示例项目按预期工作。我还以类似的方式更新了我的代码,没有保留片段实例的静态引用,目前看来还可以。@Luksprog我使用的是同一个演示项目。面对类似的问题,请提供您更正的更新。