我正在尝试将视图寻呼机保留在片段中。 View寻呼机本身包含3个其他片段。这是包含视图分页器
的Root片段import android.support.v13.app.FragmentPagerAdapter;
import android.support.v13.app.FragmentStatePagerAdapter;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import com.android.browser1.UI.ComboViews;
public class MyFragment extends Fragment implements
TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener, CombinedBookmarksCallbacks {
private TabHost mTabHost;
private ViewPager mViewPager;
public static final String EXTRA_COMBO_ARGS = "combo_args";
Bundle bundle;
Bundle extra;
public static final String EXTRA_INITIAL_VIEW = "initial_view";
public static BookmarkFragment bookmarkFragmentForPageA = null;
public static BookmarkFragment bookmarkFragmentForPageB = null;
Controller controller;
TabsAdapter mTabsAdapter;
FirstFragment first;
SecondFragment seconde;
ThirdFragment third;
public void setBundle(Bundle bundle) {
extra = bundle;// getActivity().getIntent().getExtras();
this.bundle = extra.getBundle(EXTRA_COMBO_ARGS);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mTabHost.setup();
mViewPager.setOffscreenPageLimit(2);
mTabsAdapter = new TabsAdapter(getActivity(), mTabHost, mViewPager);
new setAdapterTask().execute();
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.bookmark_view_pager, null);
mTabHost = (TabHost) view.findViewById(R.id.tabHost);
mViewPager = (ViewPager) view.findViewById(R.id.viewpager);
view.setBackgroundColor(Color.BLACK);
return view;
}
private class setAdapterTask extends AsyncTask<Void, Void, Void> {
protected Void doInBackground(Void... params) {
return null;
}
@Override
protected void onPostExecute(Void result) {
String bookmark = getResources().getString(R.string.tab_bookmarks);
String history = getResources().getString(R.string.tab_history);
String scrapmemo = getResources().getString(R.string.tab_snapshots);
mTabsAdapter.addTab(
mTabHost.newTabSpec(bookmark).setIndicator(bookmark), BrowserBookmarksPage.class, null);
mTabsAdapter.addTab(
mTabHost.newTabSpec(history).setIndicator(history), BrowserHistoryPage.class, null);
mTabsAdapter.addTab(
mTabHost.newTabSpec(scrapmemo).setIndicator(scrapmemo), BrowserSnapshotPage.class, null);
String svStr = extra.getString(EXTRA_INITIAL_VIEW, null);
ComboViews startingView = svStr != null ? ComboViews.valueOf(svStr)
: ComboViews.Bookmarks;
switch (startingView) {
case Bookmarks:
mTabHost.setCurrentTab(0);
mViewPager.setCurrentItem(0);
break;
case History:
mTabHost.setCurrentTab(1);
mViewPager.setCurrentItem(1);
break;
case ScrapMemo:
mTabHost.setCurrentTab(2);
mViewPager.setCurrentItem(2);
break;
}
}
}
public void onTabChanged(String tag) {
ComboViews startingView = tag != null ? ComboViews.valueOf(tag)
: ComboViews.Bookmarks;
switch (startingView) {
case First:
mTabHost.setCurrentTab(0);
break;
case Second:
mTabHost.setCurrentTab(1);
break;
case Third:
mTabHost.setCurrentTab(2);
break;
}
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
this.mTabHost.setCurrentTab(position);
}
@Override
public void onPageScrollStateChanged(int state) {
}
public class TabsAdapter extends FragmentStatePagerAdapter
implements TabHost.OnTabChangeListener, ViewPager.OnPageChangeListener {
private final Context mContext;
private final TabHost mTabHost;
private final ViewPager mViewPager;
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
final class TabInfo {
private final String tag;
private final Class clss;
private final Bundle args;
TabInfo(String _tag, Class _class, Bundle _args) {
tag = _tag;
clss = _class;
args = _args;
}
}
class DummyTabFactory implements TabHost.TabContentFactory {
private final Context mContext;
public DummyTabFactory(Context context) {
mContext = context;
}
@Override
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
public TabsAdapter(Activity activity, TabHost tabHost, ViewPager pager) {
super(activity.getFragmentManager());
mContext = activity;
mTabHost = tabHost;
mViewPager = pager;
mTabHost.setOnTabChangedListener(this);
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
mViewPager.setOffscreenPageLimit(3);
}
public void addTab(TabHost.TabSpec tabSpec, Class clss, Bundle args) {
tabSpec.setContent(new DummyTabFactory(mContext));
String tag = tabSpec.getTag();
TabInfo info = new TabInfo(tag, clss, args);
mTabs.add(info);
mTabHost.addTab(tabSpec);
notifyDataSetChanged();
getItem(0);
}
@Override
public int getCount() {
return mTabs.size();
}
@Override
public Fragment getItem(int position) {
Fragment fr = null;
TabInfo info = mTabs.get(position);
// Create a new fragment if necessary.
switch (position) {
case 0:
fr = new FirstFragment();
fr.setArguments(info.args);
break;
case 1:
fr = new SecondFragment ();
fr.setArguments(info.args);
break;
case 2:
fr = new ThirdFragment ();
fr.setArguments(info.args);
break;
default:
fr = new FirstFragment ();
fr.setArguments(info.args);
break;
}
return fr;
}
@Override
public int getItemPosition(Object object) {
if (object instanceof FirstFragment
|| object instanceof SecondFragment
|| object instanceof ThirdFragment )
return POSITION_NONE;
return POSITION_UNCHANGED;
}
@Override
public void onTabChanged(String tabId) {
// called when the user clicks on a tab.
int position = mTabHost.getCurrentTab();
mViewPager.setCurrentItem(position);
}
@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
@Override
public void onPageSelected(int position) {
// Unfortunately when TabHost changes the current tab, it kindly
// also takes care of putting focus on it when not in touch mode.
// The jerk.
// This hack tries to prevent this from pulling focus out of our
// ViewPager.
TabWidget widget = mTabHost.getTabWidget();
int oldFocusability = widget.getDescendantFocusability();
widget.setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS);
mTabHost.setCurrentTab(position);
widget.setDescendantFocusability(oldFocusability);
}
@Override
public void onPageScrollStateChanged(int state) {
}
}
}
当我第一次将这个片段附加到我的活动中时，我们可以通过滑动看到所有三个片段，但在背面按下后我们删除片段。之后，我再次在运行时将片段附加到相同的活动中，但只有前2个片段可见，第3个片段的内容为空。
答案 0 :(得分：1)
我正在尝试将视图寻呼机保留在片段中。 View寻呼机本身包含3个其他片段。
抱歉，其他片段中的片段是officially not supported, as indicated by Dianne Hackborn, a core Android team member。