我正在创建一个实现多个标签的应用程序，例如chrome tabs.A选项卡将保存子片段，在添加新标签时，将为新标签重新创建子片段。我面临的问题是，在我的子片段中，我有动态网格视图和列表视图。当我创建列表或网格然后新选项卡创建了列表并且网格被删除。删除标签时也会发生相同的情况。
如果已经有2个标签并且我添加了一个列表，我可以切换标签而不删除列表或网格。 我登录onActivityCreated和onStart进行测试，当我创建第二个选项卡onstart时调用2次，当我添加第3个选项卡时，它调用了3次并且喜欢！
如果我添加新标签页或删除其他标签，我需要在其他标签页中保留视图。
为什么会发生这种情况：
我的ViewPageradapter是：
public class ViewPagerAdapter extends FragmentStatePagerAdapter {
private final ArrayList<Fragment> mFragmentList = new ArrayList<>();
private final ArrayList<String> mFragmentTitleList = new ArrayList<>();
Context context;
ViewPager viewPager;
TabLayout tabLayout;
int selectedTabPosition;
private boolean doNotifyDataSetChangedOnce = false;
public ViewPagerAdapter(FragmentManager manager, Context context, ViewPager viewPager,
TabLayout tabLayout) {
super(manager);
this.context = context;
this.viewPager = viewPager;
this.tabLayout = tabLayout;
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
if (doNotifyDataSetChangedOnce) {
doNotifyDataSetChangedOnce = false;
notifyDataSetChanged();
}
return mFragmentList.size();
}
public void addFrag(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
public void removeFrag(int position) {
removeTab(position);
Fragment fragment = mFragmentList.get(position);
mFragmentList.remove(fragment);
mFragmentTitleList.remove(position);
//destroyFragmentView(viewPager, position, fragment);
notifyDataSetChanged();
if (getCount() > 0) tabLayout.setupWithViewPager(viewPager);
//viewPager.setCurrentItem(getCount() - 1);
setupTabLayout();
}
public View getTabView(final int position) {
View view = LayoutInflater.from(context).inflate(R.layout.custom_tab_item, null);
TextView tabItemName = (TextView) view.findViewById(R.id.textViewTabItemName);
ImageView tabItemAvatar =
(ImageView) view.findViewById(R.id.imageViewTabItemAvatar);
ImageButton remove = (ImageButton) view.findViewById(R.id.imageButtonRemove);
if(getCount() == 1){
remove.setVisibility(View.INVISIBLE);
}
else{
remove.setVisibility(View.VISIBLE);
}
remove.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d("Remove", "Remove");
if(getCount() != 1){
removeFrag(position);
}
else{
// Toast.makeText("Atleast One Tab is requied")
}
}
});
tabItemName.setText(mFragmentTitleList.get(position));
tabItemName.setTextColor(context.getResources().getColor(android.R.color.background_light));
tabItemAvatar.setImageResource(R.drawable.boy);
return view;
}
public void setupTabLayout() {
selectedTabPosition = viewPager.getCurrentItem();
for (int i = 0; i < tabLayout.getTabCount(); i++) {
tabLayout.getTabAt(i).setCustomView(getTabView(i));
}
}
public void removeTab(int position) {
if (tabLayout.getChildCount() > 0 && tabLayout!=null) {
tabLayout.removeTabAt(position);
}
}
@Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
@Override
public CharSequence getPageTitle(int position) {
return mFragmentTitleList.get(position);
}
}
Parent Fragment:
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_parent, container, false);
getIDs(view);
setEvents();
return view;
}
private void getIDs(View view) {
viewPager = (ViewPager) view.findViewById(R.id.my_viewpager);
tabLayout = (TabLayout) view.findViewById(R.id.my_tab_layout);
add= (ImageView) view.findViewById(R.id.imageButtonAdd1);
adapter = new ViewPagerAdapter(getFragmentManager(), getActivity(), viewPager, tabLayout);
viewPager.setAdapter(adapter);
}
int selectedTabPosition;
private void setEvents() {
tabLayout.setOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(viewPager) {
@Override
public void onTabSelected(TabLayout.Tab tab) {
super.onTabSelected(tab);
viewPager.setCurrentItem(tab.getPosition());
selectedTabPosition = viewPager.getCurrentItem();
Toast.makeText(getActivity(), "Selected " + tab.getPosition(), Toast.LENGTH_SHORT).show();
Log.d("Selected", "Selected " + tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
super.onTabUnselected(tab);
Log.d("Unselected", "Unselected " + tab.getPosition());
}
});
add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(adapter.getCount() > 4){
Toast.makeText(getActivity(), "Only 5 Tabs allowed", Toast.LENGTH_SHORT).show();
}
else {
Bundle bundle = new Bundle();
bundle.putString("data", "POS"+adapter.getCount());
FragmentChild fragmentChild = new FragmentChild();
fragmentChild.setArguments(bundle);
adapter.addFrag(fragmentChild, "POS"+adapter.getCount());
adapter.notifyDataSetChanged();
if (adapter.getCount() > 0) tabLayout.setupWithViewPager(viewPager);
viewPager.setCurrentItem(adapter.getCount() - 1);
setupTabLayout();
}
}
});
}
public void addPage(String pagename) {
Bundle bundle = new Bundle();
bundle.putString("data", pagename);
FragmentChild fragmentChild = new FragmentChild();
fragmentChild.setArguments(bundle);
adapter.addFrag(fragmentChild, pagename);
adapter.notifyDataSetChanged();
if (adapter.getCount() > 0) tabLayout.setupWithViewPager(viewPager);
viewPager.setCurrentItem(adapter.getCount() - 1);
setupTabLayout();
}
public void setupTabLayout() {
selectedTabPosition = viewPager.getCurrentItem();
for (int i = 0; i < tabLayout.getTabCount(); i++) {
tabLayout.getTabAt(i).setCustomView(adapter.getTabView(i));
}
}
我的名单存在的儿童片段：
public class FragmentChild extends Fragment {
String childname;
TextView textViewChildName;
EditText editText;
private GridView mGridView;
private ListItem mListItem;
private ListView mListview;
private ProgressBar mProgressBar;
private ProductViewAdapter mGridAdapter;
private ListViewAdapter mListAdapter = null;
private ArrayList<GridItem> mGridData;
private ArrayList<ListItem> mListData = null;
ListView listView;
CheckInterNetConnection check ;
Boolean isInternetPresent = false;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_child, container, false);
Bundle bundle = getArguments();
childname = bundle.getString("data");
getIDs(view);
setEvents();
return view;
}
private void getIDs(View view) {
//textViewChildName = (TextView) view.findViewById(R.id.textViewChild);
//textViewChildName.setText(childname);
//editText = (EditText) view.findViewById(R.id.editText);
//editText.setText("");
}
private void setEvents() {
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Log.e("onActivityCreated","onActivityCreated");
mGridView = (GridView) getView().findViewById(R.id.gridView);
mGridData = new ArrayList<>();
mGridAdapter = new ProductViewAdapter(getActivity(), R.layout.grid_product_layout, mGridData);
mGridView.setAdapter(mGridAdapter);
mListview = (ListView) getView().findViewById(R.id.list);
mListData = new ArrayList<>();
mListAdapter = new ListViewAdapter(getActivity(), R.layout.list_row, mListData);
mListview.setAdapter(mListAdapter);
}
@Override
public void onStart() {
super.onStart();
Log.e("onSTart","onSTart");
check = new CheckInterNetConnection(getActivity());
isInternetPresent = check.isConnectingToInternet();
if (isInternetPresent) {
//fetchProducts();
}
}
public void fetchProducts(){
Log.e("URL","http://13.126.17.194/products.php");
RestClientHelper.getInstance().get("http://13.126.17.194/products.php", new RestClientHelper.RestClientListener() {
@Override
public void onSuccess(String response) {
parseResult(response);
mListData.clear();
mListAdapter.setGridData(mListData);
mGridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
try {
ListItem items;
GridItem item = (GridItem) parent.getItemAtPosition(position);
items = new ListItem();
items.setName(item.getTitle());
items.setType(item.getDescription());
mListData.add(items);
}
catch(Exception e){
}
finally {
mListAdapter.setGridData(mListData);
}
}
});
}
@Override
public void onError(String error) {
}
});
}
private void parseResult(String result) {
try {
JSONObject response = new JSONObject(result);
JSONArray posts = response.optJSONArray("products");
GridItem item;
if(posts.length() <= 0){
RelativeLayout ly = (RelativeLayout) getView().findViewById(R.id.noOps);
ly.setVisibility(View.VISIBLE);
}
else {
// RelativeLayout ly = (RelativeLayout) getView().findViewById(R.id.noOps);
//ly.setVisibility(View.INVISIBLE);
for (int i = 0; i < posts.length(); i++) {
JSONObject post = posts.optJSONObject(i);
String id = post.optString("id");
String title = post.optString("name");
String description = post.optString("description");
String image = post.optString("image");
String qty = post.optString("qty");
String quantityin = post.optString("quantityin");
String price = post.optString("price");
item = new GridItem();
item.setId(id);
item.setTitle(title);
item.setDescription(description);
item.setImage(image);
item.setQuantity(qty);
item.setQuantityIn(quantityin);
item.setUnitprice(price);
mGridData.add(item);
}
}
} catch (JSONException e) {
e.printStackTrace();
}
finally {
mGridAdapter.setGridData(mGridData);
}
}
}
PARENT FRAGMENT：
public class FragmentParent extends Fragment {
private TabLayout tabLayout;
private ViewPager viewPager;
private ViewPagerAdapter adapter;
private ImageView add;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_parent, container, false);
getIDs(view);
setEvents();
return view;
}
private void getIDs(View view) {
viewPager = (ViewPager) view.findViewById(R.id.my_viewpager);
tabLayout = (TabLayout) view.findViewById(R.id.my_tab_layout);
add= (ImageView) view.findViewById(R.id.imageButtonAdd1);
adapter = new ViewPagerAdapter(getFragmentManager(), getActivity(), viewPager, tabLayout);
viewPager.setAdapter(adapter);
}
int selectedTabPosition;
private void setEvents() {
tabLayout.setOnTabSelectedListener(new TabLayout.ViewPagerOnTabSelectedListener(viewPager) {
@Override
public void onTabSelected(TabLayout.Tab tab) {
super.onTabSelected(tab);
viewPager.setCurrentItem(tab.getPosition());
selectedTabPosition = viewPager.getCurrentItem();
Toast.makeText(getActivity(), "Selected " + tab.getPosition(), Toast.LENGTH_SHORT).show();
Log.d("Selected", "Selected " + tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
super.onTabUnselected(tab);
Log.d("Unselected", "Unselected " + tab.getPosition());
}
});
add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(adapter.getCount() > 4){
Toast.makeText(getActivity(), "Only 5 Tabs allowed", Toast.LENGTH_SHORT).show();
}
else {
Bundle bundle = new Bundle();
bundle.putString("data", "POS"+adapter.getCount());
FragmentChild fragmentChild = new FragmentChild();
fragmentChild.setArguments(bundle);
adapter.addFrag(fragmentChild, "POS"+adapter.getCount());
adapter.notifyDataSetChanged();
if (adapter.getCount() > 0) tabLayout.setupWithViewPager(viewPager);
viewPager.setCurrentItem(adapter.getCount() - 1);
setupTabLayout();
}
}
});
}
public void addPage(String pagename) {
Bundle bundle = new Bundle();
bundle.putString("data", pagename);
FragmentChild fragmentChild = new FragmentChild();
fragmentChild.setArguments(bundle);
adapter.addFrag(fragmentChild, pagename);
adapter.notifyDataSetChanged();
if (adapter.getCount() > 0) tabLayout.setupWithViewPager(viewPager);
viewPager.setCurrentItem(adapter.getCount() - 1);
//setupTabLayout();
}
public void setupTabLayout() {
selectedTabPosition = viewPager.getCurrentItem();
for (int i = 0; i < tabLayout.getTabCount(); i++) {
tabLayout.getTabAt(i).setCustomView(adapter.getTabView(i));
}
}
}
更新
我能够多次解决gridview更新，但是如果我添加或删除标签，视图仍会重新初始化。请帮忙