使用此示例：我制作了自己的片段，其中包含标签主机和标签内容：
public class TabsFragment extends Fragment
{
private static final String EXTRA_TAB = "EXTRA_TAB";
private TabHost tabHost;
private TabManager tabManager;
private MaptrixFragmentActivity activity;
private Context context;
@Override
public void onAttach(Activity activity)
{
this.activity = (MaptrixFragmentActivity) activity;
this.context = activity;
super.onAttach(activity);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.fragment_tabs, container, false);
tabHost = (TabHost)view.findViewById(android.R.id.tabhost);
tabHost.setup();
tabManager = new TabManager(activity, tabHost, R.id.realtabcontent);
initTabs();
if (savedInstanceState != null)
{
tabHost.setCurrentTabByTag(savedInstanceState.getString(EXTRA_TAB));
}
return view;
}
private void initTabs()
{
// tab one
addTab(Fragment.class, null, R.drawable.icon1, Res.S(R.string.tab1));
// I have not implement the tab fragment yet!
// tab two
addTab(Fragment.class, null, R.drawable.icon2, Res.S(R.string.tab2));
}
private void addTab(Class<?> fragmenClass, Bundle bundle, int drawableId, String tag)
{
TabHost.TabSpec spec = tabHost.newTabSpec(tag);
View tabIndicator = LayoutInflater.from(context).inflate(R.layout.item_tab, tabHost.getTabWidget(), false);
ImageView icon = (ImageView) tabIndicator.findViewById(R.id.tab_image);
icon.setImageResource(drawableId);
spec.setIndicator(tabIndicator);
tabManager.addTab(spec, fragmenClass, bundle);
}
@Override
public void onSaveInstanceState(Bundle outState)
{
super.onSaveInstanceState(outState);
outState.putString(EXTRA_TAB, tabHost.getCurrentTabTag());
}
public static class TabManager implements TabHost.OnTabChangeListener
{
private final FragmentActivity activity;
private final TabHost tabHost;
private final int containerID;
private final HashMap<String, TabInfo> tabs = new HashMap<String, TabInfo>();
TabInfo lastTab;
TabFactory factory;
public TabManager(FragmentActivity activity, TabHost tabHost, int containerID)
{
this.activity = activity;
this.tabHost = tabHost;
this.containerID = containerID;
factory = new TabFactory(activity);
tabHost.setOnTabChangedListener(this);
}
public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args)
{
tabSpec.setContent(factory);
String tag = tabSpec.getTag();
TabInfo info = new TabInfo(tag, clss, args);
info.fragment = activity.getSupportFragmentManager().findFragmentByTag(tag);
if (info.fragment != null && !info.fragment.isDetached())
{
FragmentTransaction ft = activity.getSupportFragmentManager().beginTransaction();
ft.detach(info.fragment);
ft.commit();
}
tabs.put(tag, info);
tabHost.addTab(tabSpec);
}
@Override
public void onTabChanged(String tabId)
{
TabInfo newTab = tabs.get(tabId);
if (lastTab != newTab)
{
FragmentTransaction ft = activity.getSupportFragmentManager().beginTransaction();
if (lastTab != null) {
if (lastTab.fragment != null)
{
ft.detach(lastTab.fragment);
}
}
if (newTab != null)
{
if (newTab.fragment == null)
{
newTab.fragment = Fragment.instantiate(activity, newTab.clss.getName(), newTab.args);
ft.add(containerID, newTab.fragment, newTab.tag);
}
else
{
ft.attach(newTab.fragment);
}
}
lastTab = newTab;
ft.commit();
}
}
}
private static class TabInfo
{
private final String tag;
private final Class<?> clss;
private final Bundle args;
private Fragment fragment;
TabInfo(String _tag, Class<?> _class, Bundle _args)
{
tag = _tag;
clss = _class;
args = _args;
}
}
private static class TabFactory implements TabHost.TabContentFactory
{
private final Context mContext;
public TabFactory(Context context)
{
mContext = context;
}
@Override
public View createTabContent(String tag)
{
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
}
但是当设备改变方向时，onCreateView 方法会调用两次或多次。
我的 FragmentActivity 是：
public class MaptrixFragmentActivity extends FragmentActivity
{
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.factivity);
replace(R.id.factivity_content, new TabsFragment(), false, false);
}
@Override
protected void onResume()
{
super.onResume();
}
@Override
protected void onPause()
{
super.onPause();
}
public void replace(int rootView, Fragment fragment)
{
replace(rootView, fragment, true, true);
}
public void replace(int rootView, Fragment fragment, boolean backStack)
{
replace(rootView, fragment, backStack, true);
}
public void replace(int rootView, Fragment fragment, boolean backStack, boolean animation)
{
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
if (animation) transaction.setCustomAnimations(R.anim.fragment_open, R.anim.fragment_close, R.anim.fragment_open_stack, R.anim.fragment_close_stack);
if (backStack) transaction.addToBackStack(null);
transaction.replace(R.id.factivity_maptrix_content, fragment);
transaction.commit();
}
}
为什么我有这个错误？