アダプターのデータを変更して削除または再作成する必要がある場合は、android Support4Demos に簡単な変更を加えて、アダプターのフラグメント ページを更新する方法を示します。
/**
* Demonstrates combining a TabHost with a ViewPager to implement a tab UI
* that switches between tabs and also allows the user to perform horizontal
* flicks to move between the tabs.
*/
public class FragmentTabsPager extends FragmentActivity implements View.OnClickListener,FragmentCallBack{
TabHost mTabHost;
ViewPager mViewPager;
TabsAdapter mTabsAdapter;
private Button mBtn_nextFragment;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_tabs_pager);
mTabHost = (TabHost)findViewById(android.R.id.tabhost);
mBtn_nextFragment=(Button)findViewById(R.id.btn_next_fragment);
mBtn_nextFragment.setOnClickListener(this);
mTabHost.setup();
mViewPager = (ViewPager)findViewById(R.id.pager);
mTabsAdapter = new TabsAdapter(this, mTabHost, mViewPager);
mTabsAdapter.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),
FragmentStackSupport.CountingFragment.class, null);
mTabsAdapter.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),
LoaderCursorSupport.CursorLoaderListFragment.class, null);
mTabsAdapter.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),
LoaderCustomSupport.AppListFragment.class, null);
mTabsAdapter.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),
LoaderThrottleSupport.ThrottledLoaderListFragment.class, null);
if (savedInstanceState != null) {
mTabHost.setCurrentTabByTag(savedInstanceState.getString("tab"));
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putString("tab", mTabHost.getCurrentTabTag());
}
/**
* This is a helper class that implements the management of tabs and all
* details of connecting a ViewPager with associated TabHost. It relies on a
* trick. Normally a tab host has a simple API for supplying a View or
* Intent that each tab will show. This is not sufficient for switching
* between pages. So instead we make the content part of the tab host
* 0dp high (it is not shown) and the TabsAdapter supplies its own dummy
* view to show as the tab content. It listens to changes in tabs, and takes
* care of switch to the correct paged in the ViewPager whenever the selected
* tab changes.
*/
public static 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>();
static 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;
}
}
static 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(FragmentActivity activity, TabHost tabHost, ViewPager pager) {
super(activity.getSupportFragmentManager());
mContext = activity;
mTabHost = tabHost;
mViewPager = pager;
mTabHost.setOnTabChangedListener(this);
mViewPager.setAdapter(this);
mViewPager.setOnPageChangeListener(this);
}
public void clearData(){
mTabs.clear();
notifyDataSetChanged();
}
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();
}
@Override
public int getCount() {
return mTabs.size();
}
@Override
public Fragment getItem(int position) {
TabInfo info = mTabs.get(position);
return Fragment.instantiate(mContext, info.clss.getName(), info.args);
}
@Override
public void onTabChanged(String tabId) {
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) {
}
}
@Override
public void onClick(View v) {
mTabsAdapter.clearData();
mTabHost.clearAllTabs();
//mTabsAdapter.notifyDataSetChanged();
Bundle mBundleSimple=new Bundle();
mBundleSimple.putString("data", "SimpleData");
mTabsAdapter.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),
FragmentStackSupport.CountingFragment.class, mBundleSimple);
Bundle mBundleContacts=new Bundle();
mBundleContacts.putString("data", "Contacts");
mTabsAdapter.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),
LoaderCursorSupport.CursorLoaderListFragment.class, mBundleContacts);
Bundle mBundleCustom=new Bundle();
mBundleCustom.putString("data", "Custom");
mTabsAdapter.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),
LoaderCustomSupport.AppListFragment.class, mBundleCustom);
Bundle mBundleThrottle=new Bundle();
mBundleThrottle.putString("data", "Throttle");
mTabsAdapter.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),
LoaderThrottleSupport.ThrottledLoaderListFragment.class, mBundleThrottle);
mViewPager.setAdapter(mTabsAdapter);
}
@Override
public void ClickButton(String strToken) {
if(strToken.equalsIgnoreCase("OneBtn")){
mTabsAdapter.clearData();
mTabHost.clearAllTabs();
//mTabsAdapter.notifyDataSetChanged();
Bundle mBundleSimple=new Bundle();
mBundleSimple.putString("data", "SimpleData");
mTabsAdapter.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),
FragmentStackSupport.CountingFragment.class, mBundleSimple);
Bundle mBundleContacts=new Bundle();
mBundleContacts.putString("data", "SimpleData");
mTabsAdapter.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),
LoaderCursorSupport.CursorLoaderListFragment.class, mBundleContacts);
Bundle mBundleCustom=new Bundle();
mBundleCustom.putString("data", "Custom");
mTabsAdapter.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),
LoaderCustomSupport.AppListFragment.class, mBundleCustom);
Bundle mBundleThrottle=new Bundle();
mBundleThrottle.putString("data", "Throttle");
mTabsAdapter.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),
LoaderThrottleSupport.ThrottledLoaderListFragment.class, mBundleThrottle);
mViewPager.setAdapter(mTabsAdapter);
}
}
}
上記の Fragment Activity では、アダプター データを再作成するために以下の変更を行いました。
1.フラグメントリストをクリアするパブリック関数を作成します。この例では mTabs です。2.フラグメント配列をクリアした後、必要な変更を加えて新しいフラグメントを追加します。上記のクラスでは、バンドルを使用してフラグメントを追加し、すべてのフラグメントクラスで取得できることがわかります。3.ViewPagerでAdaperを設定します。
以下は Fragment のコードを保持するクラスです。
public class FragmentStackSupport extends FragmentActivity {
int mStackLevel = 1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.fragment_stack);
// Watch for button clicks.
Button button = (Button)findViewById(R.id.new_fragment);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
addFragmentToStack();
}
});
button = (Button)findViewById(R.id.home);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// If there is a back stack, pop it all.
FragmentManager fm = getSupportFragmentManager();
if (fm.getBackStackEntryCount() > 0) {
fm.popBackStack(fm.getBackStackEntryAt(0).getId(),
FragmentManager.POP_BACK_STACK_INCLUSIVE);
}
}
});
if (savedInstanceState == null) {
// Do first time initialization -- add initial fragment.
Fragment newFragment = CountingFragment.newInstance(mStackLevel);
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.simple_fragment, newFragment).commit();
} else {
mStackLevel = savedInstanceState.getInt("level");
}
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("level", mStackLevel);
}
void addFragmentToStack() {
mStackLevel++;
// Instantiate a new fragment.
Fragment newFragment = CountingFragment.newInstance(mStackLevel);
// Add the fragment to the activity, pushing this transaction
// on to the back stack.
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.simple_fragment, newFragment);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(null);
ft.commit();
}
public static class CountingFragment extends Fragment implements OnClickListener {
int mNum;
Button mBtnOne;
FragmentCallBack mFragmentCallBack;
/**
* Create a new instance of CountingFragment, providing "num"
* as an argument.
*/
static CountingFragment newInstance(int num) {
CountingFragment f = new CountingFragment();
// Supply num input as an argument.
Bundle args = new Bundle();
args.putInt("num", num);
f.setArguments(args);
return f;
}
/**
* When creating, retrieve this instance's number from its arguments.
*/
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mNum = getArguments() != null ? getArguments().getInt("num") : 1;
if(getArguments()!=null){
if(getArguments().containsKey("data")){
String dataIs=getArguments().getString("data");
Log.v("LOG_TAG", "THis Tab data is "+ dataIs );
}
}
}
/**
* The Fragment's UI is just a simple text view showing its
* instance number.
*/
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if(getArguments()!=null){
if(getArguments().containsKey("data")){
String dataIs=getArguments().getString("data");
Log.v("LOG_TAG", "THis Tab data is onCreateView "+ dataIs );
}
}
View v = inflater.inflate(R.layout.hello_world, container, false);
TextView tv = (TextView) v.findViewById(R.id.text);
mBtnOne=(Button)v.findViewById(R.id.btn_one);
mBtnOne.setOnClickListener(this);
tv.setText("Fragment #" + mNum);
tv.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.gallery_thumb));
return v;
}
@Override
public void onClick(View v) {
try{
mFragmentCallBack=(FragmentCallBack) this.getActivity();
mFragmentCallBack.ClickButton("OneBtn");
}catch(ClassCastException classExc){
classExc.printStackTrace();
}
}
}
}
フラグメントのいずれかで何かが変更された場合は、ViewPager を保持する FragmentActivity に CallBack を送信する 1 つのインターフェイスを作成する必要があるため、既存の Fragment を削除して再度作成することができます。
これが私のインターフェースクラスです。
public interface FragmentCallBack {
public void ClickButton(String strToken);
}
コードで同じことを行う方法を理解していただければ幸いです。