我有点似乎无法找到问题。
我有一个实现自定义TabAdapter的FragmentStatePagerAdapter。除了我有一种情况，FragmentStatePagerAdapter中的一个片段可能会改变一些需要所有片段重新创建自己的视图的项目。
例如，在片段D中，用户更改了某些内容 - ＆gt;那么片段A，B，C中的值需要改变。这在片段A和B中立即发生，因为它们的视图尚未创建。但是，片段C已经创建，因为它似乎始终创建了3个片段，至少在默认情况下是这样（前一个，当前一个，下一个）。因此，片段C不会更新。
所以最终我需要一种方法来强制适配器中的所有片段在其中一个片段（A，B，C或D）发生变化时重新创建视图。
这是我的FragmentStatePagerAdapter
public class MyTabsAdapter extends FragmentStatePagerAdapter implements
TabsAdapter {
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
private final ViewPager mPager;
private Activity mContext;
/*
* TabInfo- Simple object to keep track of the tabs.
*/
private class TabInfo {
private String fragName;
private String title;
TabInfo(String fragName, String title) {
this.fragName = fragName;
this.title = title;
}
String getFragName() {
return this.fragName;
}
String getTitle() {
return this.title;
}
}
public MyTabsAdapter(FragmentActivity ctx, ViewPager pager) {
super(ctx.getSupportFragmentManager());
this.mContext = ctx;
this.mPager = pager;
this.mPager.setAdapter(this);
}
/*
* getView - get Tab view
*/
@SuppressLint("DefaultLocale")
public View getView(int position) {
Button tab;
LayoutInflater inflater = mContext.getLayoutInflater();
tab = (Button) inflater.inflate(R.layout.tab_scrolling, null);
tab.setText(this.mTabs.get(position).getTitle().toUpperCase());
return tab;
}
public void addTab(String fragName, String title) {
TabInfo info = new TabInfo(fragName, title);
mTabs.add(info);
}
@Override
public Fragment getItem(int position) {
String fragName = mTabs.get(position).getFragName();
if (fragName == "FragmentA") {
return FragmentA.newInstance();
} else if (fragName == "FragmentB") {
return FragmentB.newInstance();
} else if (fragName == "FragmentC") {
return FragmentC.newInstance();
} else if (fragName == "FragmentD") {
return FragmentD.newInstance();
}
return null;
}
@Override
public int getCount() {
return mTabs.size();
}
}
只需通过以下方式添加片段：
MyTabsAdapter mAdapter = new MyTabsAdapter(this, myViewPager);
mAdapter.addTab("FragmentB", "Fragment B")
这一切都很好，我对Tabs adapter / views / etc没有任何问题。只是在寻找我的能力＆＃34; Force＆＃34;当FragmentA / B / C / D中的某些内容发生变化时，适配器删除/重新创建其他项目。
谢谢，如果需要，将提供更多信息
答案 0 :(得分：0)
如果您需要更改您的适配器数据以删除或重新创建我已经在Android Support4Demos中进行了简单的更改，以演示我如何更新我的适配器的片段页面。
/**
* 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);
}
}
}
在上面的片段活动中，我在下面进行了更改以重新创建适配器数据。
1.制作清除片段列表的公共功能，在此示例中为mTabs。 2.在清除片段数组之后添加你的新片段与你需要的更改，在上面的类中你可以看到我已经添加了片段与它的包，我可以进入所有Fragment类。 3.在ViewPager中设置Adaper。
下面是包含Fragment代码的类。
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();
}
}
}
}
现在当你的任何一个片段发生变化时，你需要创建一个接口，将CallBack发送到FragmentActivity来保存你的ViewPager，这样你就可以删除现有的Fragment并重新创建它。
这是我的界面类。
public interface FragmentCallBack {
public void ClickButton(String strToken);
}
希望您能在代码中了解如何做到这一点。