Android 如何解决viewpager:指定的子项已具有父项。必须对子对象&x27;调用removeView();她先是父母
在我的项目中,我使用viewpager,它有三个选项卡,分别名为Android 如何解决viewpager:指定的子项已具有父项。必须对子对象&x27;调用removeView();她先是父母,android,google-maps,android-viewpager,Android,Google Maps,Android Viewpager,在我的项目中,我使用viewpager,它有三个选项卡,分别名为History,Main,Map,Main活动包含计时器、秒表等。Map显示谷歌地图。现在我只使用简单的文本视图 Viewpager流方向:历史-主-地图 我将Main设置为当前项目(默认主标签显示)。现在,当我从MainMap和MapMain滑动时,它的工作非常完美。但是当从MainHistory刷卡时,没有错误,只能从History返回到Main(HistoryMain)eclipse给我如下错误: E/AndroidRunti
History
,Main
,Map
,Main活动包含计时器、秒表等。Map显示谷歌地图。现在我只使用简单的文本视图
Viewpager流方向:历史-主-地图
我将Main设置为当前项目(默认主标签显示)。现在,当我从MainMap和MapMain滑动时,它的工作非常完美。但是当从MainHistory刷卡时,没有错误,只能从History返回到Main(HistoryMain)eclipse给我如下错误:
E/AndroidRuntime( 533): java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.
仅供参考,我正在地图活动中使用意图。请检查下面的代码。请告诉我如何解决我的问题
ViewPager类:
@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;
}
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;
}
}
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;
}
........
}
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());
}
}
历史。课程:
@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;
}
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;
}
}
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;
}
........
}
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());
}
}
Main.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;
}
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;
}
}
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;
}
........
}
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());
}
}
Map.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;
}
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;
}
}
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;
}
........
}
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());
}
}
日志:
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}
谢谢
编辑:
@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;
}
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;
}
}
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;
}
........
}
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());
}
}
在地图活动中没有意图,它可以正常工作。我的意思是,当我在地图中使用与历史相同的内容时,没有任何错误。我也遇到了这个问题
只需添加单行mviewpage.setOffscreenPageLimit(3)即可解决此问题代码>
公共类SwipeyTabsSampleActivity扩展了FragmentActivity{
...
@凌驾
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mViewPager=(ViewPager)findViewById(R.id.ViewPager);
MTAB=(SwipeyTabs)findViewById(R.id.SwipeyTabs);
SwipeyAbsPageRadapter适配器=新SwipeyAbsPageRadapter(此,
getSupportFragmentManager());
mViewPager.setAdapter(适配器);
setOffscreenPageLimit(3);我在使用
View res = inflater.inflate(R.layout.fragment_guide_search, container);
在Fragment.onCreateView(
你必须打电话
View res = inflater.inflate(R.layout.fragment_guide_search, container, false);
或
首先,RB Patel关于插入代码的回答(如下所示)很有魅力,但当我读到这个特性时,我意识到这是一个潜在的优化,实际上并不是bug的解决方案
mViewPager.setOffscreenPageLimit(3);
Android开发者网站对这种方法作了如下说明:
setOffscreenPageLimit(int limit)-设置应
将保留在视图层次结构中当前页面的任一侧
处于空闲状态
这似乎只是对当前页面右侧或左侧缓存的页面数量设置了一个限制。在我的情况下,这只是解决问题的一个创可贴,是的,错误停止了,事情顺利进行,但我的程序中仍然隐藏着错误代码,根本无法执行。我相信这个方法是用来作为操作的优化,而不是对错误的实际修复
我在扩展PagerAdapter的自定义类中尝试重载InstanceItem()方法时遇到此问题。我的错误是在导航回以前访问/实例化过的选项卡/页面后引发的
我是Android新手,但我会尽力解释我的解决方案。引发此错误的行如下:
v.addView(child);
如果我理解正确的话,这是令人窒息的,因为之前已经实例化了子对象并为其分配了父对象
当我导航回以前访问过的视图/页面时,我试图将一个已经有父布局视图的视图添加到新布局中,因此出现了错误
解决方案:我只是通过查看是否设置了父视图来检查我试图显示(实例化)的子视图是否已经在其他地方实例化。如果子视图已经创建,那么我只是使用子视图的父视图,而不是创建新布局
这是我的代码(如果冒犯了任何专家,我深表歉意):
下面是我的解决方案(在每个片段中使用),它既允许平滑,又避免了内存问题:
...
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;
}
。。。
私人停车场;
私有WeakReference mRootView=null;
...
@凌驾
创建视图上的公共视图(最终布局扁平充气机、最终视图组容器、最终捆绑保存状态)
{
如果(充气机!=null)
mInflater=充气机;
其他的
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)
((视图组)父级)。移除视图(根视图);
}
其他的
{
rootView=mInflater.flate(R.layout.fragment\u测试,null,false);
mRootView=新的WeakReference(rootView);
}
返回rootView;
}
如果使用FragmentPagerAdapter,只需在FragmentPagerAdapter中使用destroyItem方法即可
@Override
public void destroyItem(ViewGroup container, int position, Object object)
{
FragmentTransaction ft=fm.beginTransaction();
ft.remove((Fragment) object);
ft.commit();
}
setOffscreenPageLimit(int limit)会消耗更多内存,在某些情况下,它的工作并不完美。
其在任一侧的保留状态请参见说明。setOffscreenPageLimit(int limit)-设置在空闲状态下应保留在视图层次结构中当前页面任一侧的页数。//如果要添加的子视图已绑定到父视图,则从父视图中删除子视图,然后再次添加到容器中
if (v.getParent() != null) {
((ViewGroup) v.getParent()).removeView(v);
}
container.addView(v);
对于适配器,如果您与tabLayout或viewPager一起使用,请使用getChildFragmentManager()
替换为getActivity().getSupportFragmentManager()
,如下所示
TabAdapter adapter=new TabAdapter(getActivity(),getActivity().getSupportFragmentManager());
检查布局文件中是否有任何ConstraintLayout(或类似内容)。原因可能是