问题
Into my project I am using viewpager with three tabs named History,Main,Map.Main activity contain Timer,stopwatch,etc. Map display the google map. and into History right now I am using only simple Textview.
Viewpager flow direction : History - Main - Map
I set the Main as the current item(Bydefault Main tag display).Now when I am swipe from Main > Map and Map > Main its working perfect. but when swipe from Main > History there is no error but back return from History to Main( History > Main) eclipse give me error like :
E/AndroidRuntime( 533): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
And FYI I am using intent into Map Activity.Please check below code.Please let me know how can solve my problem.
ViewPager class:
@Override
public Fragment getItem(int position) {
// return SwipeyTabFragment.newInstance(TITLES[position]);
Fragment f = new Fragment();
switch (position) {
case 0:
f = History.newInstance(position);
break;
case 1:
f = Main.newInstance(position);
break;
case 2:
f = Map.newInstance(position);
break;
}
return f;
}
History.class:
public class History extends Fragment {
public static Fragment newInstance(int position) {
History f = new History();
Bundle args = new Bundle();
args.putInt("title", position);
f.setArguments(args);
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ViewGroup root = (ViewGroup) inflater.inflate(R.layout.history, null);
( (TextView) root.findViewById(R.id.text)).setText("Hello");
return root;
}
}
Main.class :
public class Main extends Fragment implements GPSCallback {
......
public static Fragment newInstance(int position) {
Main f = new Main();
Bundle args = new Bundle();
args.putInt("title", position);
f.setArguments(args);
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final ViewGroup root = (ViewGroup) inflater
.inflate(R.layout.main, null);
.......
return root;
}
........
}
Map.class :
public class Map extends Fragment {
private static final String KEY_STATE_BUNDLE = "localActivityManagerState";
private LocalActivityManager mLocalActivityManager;
protected LocalActivityManager getLocalActivityManager() {
return mLocalActivityManager;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle state = null;
if (savedInstanceState != null) {
state = savedInstanceState.getBundle(KEY_STATE_BUNDLE);
}
mLocalActivityManager = new LocalActivityManager(getActivity(), true);
mLocalActivityManager.dispatchCreate(state);
}
public static Fragment newInstance(int position) {
Map f = new Map();
Bundle args = new Bundle();
args.putInt("title", position);
f.setArguments(args);
return f;
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Intent i = new Intent(getActivity(), MapViewActivity.class);
// Intent i = new Intent(getActivity(), hellogooglemap.class);
Window w = mLocalActivityManager.startActivity("tag", i);
View currentView=w.getDecorView();
currentView.setVisibility(View.VISIBLE);
currentView.setFocusableInTouchMode(true);
((ViewGroup) currentView).setDescendantFocusability(ViewGroup.FOCUS_AFTER_DESCENDANTS);
return currentView;
/*ViewGroup root = (ViewGroup) inflater.inflate(R.layout.history, null);
( (TextView) root.findViewById(R.id.text)).setText("Hello");
return root;*/
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putBundle(KEY_STATE_BUNDLE,
mLocalActivityManager.saveInstanceState());
}
@Override
public void onResume() {
super.onResume();
mLocalActivityManager.dispatchResume();
}
@Override
public void onPause() {
super.onPause();
mLocalActivityManager.dispatchPause(getActivity().isFinishing());
}
@Override
public void onStop() {
super.onStop();
mLocalActivityManager.dispatchStop();
}
@Override
public void onDestroy() {
super.onDestroy();
mLocalActivityManager.dispatchDestroy(getActivity().isFinishing());
}
}
Logcat :
E/AndroidRuntime( 533): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
E/AndroidRuntime( 533): at android.view.ViewGroup.addViewInner(ViewGroup.java:1976)
E/AndroidRuntime( 533): at android.view.ViewGroup.addView(ViewGroup.java:1871)
E/AndroidRuntime( 533): at android.view.ViewGroup.addView(ViewGroup.java:1828)
E/AndroidRuntime( 533): at android.view.ViewGroup.addView(ViewGroup.java:1808)
E/AndroidRuntime( 533): at android.support.v4.app.NoSaveStateFrameLayout.wrap(NoSaveStateFrameLayout.java:40)
E/AndroidRuntime( 533): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:874)
E/AndroidRuntime( 533): at android.support.v4.app.FragmentManagerImpl.attachFragment(FragmentManager.java:1240)
E/AndroidRuntime( 533): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:612)
E/AndroidRuntime( 533): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1416)
E/AndroidRuntime( 533): at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:431)
E/AndroidRuntime( 533): at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:139)
E/AndroidRuntime( 533): at android.support.v4.view.ViewPager.populate(ViewPager.java:804)
E/AndroidRuntime( 533): at android.support.v4.view.ViewPager.completeScroll(ViewPager.java:1280)
E/AndroidRuntime( 533): at android.support.v4.view.ViewPager.computeScroll(ViewPager.java:1176)
E/AndroidRuntime( 533): at android.view.ViewGroup.drawChild(ViewGroup.java:1562)
E/AndroidRuntime( 533): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
E/AndroidRuntime( 533): at android.view.ViewGroup.drawChild(ViewGroup.java:1644)
E/AndroidRuntime( 533): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
E/AndroidRuntime( 533): at android.view.View.draw(View.java:6883)
E/AndroidRuntime( 533): at android.widget.FrameLayout.draw(FrameLayout.java:357)
E/AndroidRuntime( 533): at android.view.ViewGroup.drawChild(ViewGroup.java:1646)
E/AndroidRuntime( 533): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
E/AndroidRuntime( 533): at android.view.ViewGroup.drawChild(ViewGroup.java:1644)
E/AndroidRuntime( 533): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
E/AndroidRuntime( 533): at android.view.View.draw(View.java:6883)
E/AndroidRuntime( 533): at android.widget.FrameLayout.draw(FrameLayout.java:357)
E/AndroidRuntime( 533): at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1862)
E/AndroidRuntime( 533): at android.view.ViewRoot.draw(ViewRoot.java:1522)
E/AndroidRuntime( 533): at android.view.ViewRoot.performTraversals(ViewRoot.java:1258)
E/AndroidRuntime( 533): at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
E/AndroidRuntime( 533): at android.os.Handler.dispatchMessage(Handler.java:99)
E/AndroidRuntime( 533): at android.os.Looper.loop(Looper.java:130)
E/AndroidRuntime( 533): at android.app.ActivityThread.main(ActivityThread.java:3683)
E/AndroidRuntime( 533): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 533): at java.lang.reflect.Method.invoke(Method.java:507)
E/AndroidRuntime( 533): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
E/AndroidRuntime( 533): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
E/AndroidRuntime( 533): at dalvik.system.NativeStart.main(Native Method)
W/ActivityManager( 68): Force finishing activity com.android.gps/.viewpager.SwipeyTabsSampleActivity
W/ActivityManager( 68): Activity pause timeout for HistoryRecord{40716740 com.android.gps/.viewpager.SwipeyTabsSampleActivity}
Thanks.
EDIT:
Without intent into Map activity it works pwrfect.I mean when i am using same as history into map there is no any error.
回答1:
I have also faced this problem.
You can solve it by just add single line mViewPager.setOffscreenPageLimit(3);
public class SwipeyTabsSampleActivity extends FragmentActivity {
...
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mViewPager = (ViewPager) findViewById(R.id.viewpager);
mTabs = (SwipeyTabs) findViewById(R.id.swipeytabs);
SwipeyTabsPagerAdapter adapter = new SwipeyTabsPagerAdapter(this,
getSupportFragmentManager());
mViewPager.setAdapter(adapter);
mViewPager.setOffscreenPageLimit(3); <------ Add this one
}
}
Good Luck.
回答2:
I had the same problem when I used
View res = inflater.inflate(R.layout.fragment_guide_search, container);
inside Fragment.onCreateView(...
You must call
View res = inflater.inflate(R.layout.fragment_guide_search, container, false);
or
View res = inflater.inflate(R.layout.fragment_guide_search, null);
回答3:
First, the answer by RB Patel to insert code (shown below), worked like a charm, but as I read about this feature, I realized it was intended as a potential optimization and isn't actually the solution to the bug.
mViewPager.setOffscreenPageLimit(3);
The Android Developer site says the following about this method:
setOffscreenPageLimit(int limit) - Set the number of pages that should be retained to either side of the current page in the view hierarchy in an idle state.
It seems like this just sets a limit on the number of pages cached to the right or left of the current page. In my case this was just a band aid for the problem, yes the error stopped and things worked smoothly, but I still had bad code lurking in my program which simply not being executed. I believe this method was intended to be used as an optimization and not an actual fix to the bug.
I ran into this problem when trying to overload the instantiateItem() method in a custom class which extends PagerAdapter. My error was thrown after I would navigate back to a tab/page which I had previously visited/instantiated.
I am new to Android but I'll do my best to explain my solution. The line which throw this error was the following:
v.addView(child);
If I understand this correctly, it was choking because the child was already instantiated previously and assigned a parent.
When I would navigate back to a previously visited view/page I was trying to add a view which already had a parent layout view to a new Layout, hence the error.
Solution: I just checked to see if the child view I was trying to display (instantiate) was already instantiated somewhere else by seeing if it had a parent view set. If the child view had already been created, then I just used the parent of the child view instead of creating a new Layout.
Here is my code (I apologize if it offends any experts):
@Override
public Object instantiateItem(View container, int position) {
LinearLayout v = new LinearLayout(mContext);
//the view being loaded (unless it already was then we have to handle it)
View child = mViews.get(position);
//If the child view was loaded already then it will have a parent view it belongs to
//We return the parent view instead of adding the child to the LinearLayout we just created and returning that new layout.
if(child.getParent() != null) {
View parent = (View) child.getParent();
((ViewPager) container).addView(parent);
return parent;
}
//first time instantiating a child view/page
v.addView(child);
// These lines execute the first time a given page is instantiated
((ViewPager) container).addView(v);
return v;
}
回答4:
Here's my solution (used in each of the fragments) , which allows both smoothness and avoids memory problems:
...
private LayoutInflater mInflater;
private WeakReference<View> mRootView = null;
...
@Override
public View onCreateView(final LayoutInflater inflater, final ViewGroup container, final Bundle savedInstanceState)
{
if (inflater != null)
mInflater = inflater;
else
mInflater = LayoutInflater.from(getActivity());
View rootView = mRootView == null ? null : mRootView.get();
if (rootView != null)
{
final ViewParent parent = rootView.getParent();
if (parent != null && parent instanceof ViewGroup)
((ViewGroup) parent).removeView(rootView);
}
else
{
rootView = mInflater.inflate(R.layout.fragment_test, null, false);
mRootView = new WeakReference<View>(rootView);
}
return rootView;
}
回答5:
@Override
public Object instantiateItem(View arg0, int arg1) {
Log.d("instantiateItem", ""+arg0+" "+arg1);
try {
if(mListViews.get(arg1).getParent()==null)
((ViewPager) arg0).addView(mListViews.get(arg1), 0);
else{
// I am new to android, it is strange that the view to be added is already bound to a parent
// Through trials and error I solve this problem with the following codes
// Add that the element of mlistviews is listview in pagerview;
((ViewGroup)mListViews.get(arg1).getParent()).removeView(mListViews.get(arg1));
((ViewPager) arg0).addView(mListViews.get(arg1), 0);
}
} catch (Exception e) {
Log.d("parent=", ""+mListViews.get(arg1).getParent());
e.printStackTrace();
}
return mListViews.get(arg1);
}
回答6:
if you are working with FragmentPagerAdapter then just use destroyItem method inside FragmentPagerAdapter.
@Override
public void destroyItem(ViewGroup container, int position, Object object)
{
FragmentTransaction ft=fm.beginTransaction();
ft.remove((Fragment) object);
ft.commit();
}
setOffscreenPageLimit(int limit) consumes more memory and in some cases its not works perfectly. its retain state in either side see description.setOffscreenPageLimit(int limit) - Set the number of pages that should be retained to either side of the current page in the view hierarchy in an idle state.
回答7:
// if the child view to be added is already bound to a parent, then remove the child from the parent and then add again to the container.
if (v.getParent() != null) {
((ViewGroup) v.getParent()).removeView(v);
}
container.addView(v);
来源：https://stackoverflow.com/questions/13559353/how-to-solve-for-viewpager-the-specified-child-already-has-a-parent-you-must