如何从 Web 服务将 ViewPager 中的 Fragments 添加到 TabLayout?
How to add Fragments in ViewPager to TabLayout from a web service?
我正在尝试向基于 TabLayout-ViewPager-Fragment
的应用程序添加选项卡 dynamically.The TabLayout
使用自定义视图,在 [=16= 之上有一个 ImageView
].
我现在想要的是根据从 PHP/MySQL 网络服务创建的 JSONArray
中的 JSONObjects
的数量添加选项卡。我在 PagerAdapter
中尝试了下面的方法,但它抛出:
java.lang.IllegalStateException: Can't change tag of fragment TstFrag{df80bc8 #0 id=0x7f080157 android:switcher:2131231063:0}: was android:switcher:2131231063:0 now android:switcher:2131231063:1
.
方法如下我的适配器
public class FrgAdapter extends FragmentStatePagerAdapter {
private List<Fragment> mFragmentList = new ArrayList<>();
private List<String> mFragmentTitleList = new ArrayList<>();
public FrgAdapter(FragmentManager fm) {
super(fm);
}
public FrgAdapter(FragmentManager fm, List<Fragment> mFragmentList, List<String> mFragmentTitleList) {
super(fm);
this.mFragmentList = mFragmentList;
this.mFragmentTitleList = mFragmentTitleList;
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
public void insertFromJSONObject(JSONObject jsonObject, Fragment fragment, CircularImageView imageView, TextView textView) throws JSONException {
JSONArray dataArray = jsonObject.getJSONArray("data");
for (int i = 0; i < dataArray.length(); i++) {
JSONObject sectionObj = (JSONObject) dataArray.get(i);
JSONArray sectionsArray = sectionObj.getJSONArray("section");
for (int j = 0; j < sectionsArray.length(); j++) {
JSONObject obj = (JSONObject) sectionsArray.get(j);
Picasso.get().load(obj.getString("imag")).into(imageView);
mFragmentList.add(fragment);
mFragmentTitleList.add(obj.getString("name"));
textView.setText(obj.getString("name"));
notifyDataSetChanged();
}
}
}
@Override
public CharSequence getPageTitle(int position) {
return null;
}}
这里是在我的 activity 中调用方法来添加片段的地方:
private void setUpViewPager(ViewPager viewPager, View view) {
adapter = new FrgAdapter(getSupportFragmentManager());
/*adapter.addFragment(new MleFrag(), "Men");
adapter.addFragment(new FmlFrag(), "Women");
adapter.addFragment(new ChdFrag(), "Children");
adapter.addFragment(new AceFrag(), "Accessories");
*/
String url = "https://44091ee6.ngrok.io/Glam/men.json";
AndroidNetworking.get(url)
.setPriority(Priority.MEDIUM)
.build()
.getAsJSONObject(new JSONObjectRequestListener() {
@Override
public void onResponse(JSONObject response) {
try {
adapter.insertFromJSONObject(response, new TstFrag(), view.findViewById(R.id.circularImageView), view.findViewById(R.id.text_header));
adapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
public void onError(ANError anError) {
Toast.makeText(getApplicationContext(), anError.toString(), Toast.LENGTH_LONG).show();
}
});
adapter.notifyDataSetChanged();
viewPager.setAdapter(adapter);
}
这是我的Fragment
。在我看来,我想在每次需要时重复使用这个 Fragment
。
public class TstFrag extends Fragment {
public TstFrag() {
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.layout_cht, container, false);
}}
你可以试试这个:
adapter.insertFromJSONObject(response, view.findViewById(R.id.circularImageView), view.findViewById(R.id.text_header));
adapter.notifyDataSetChanged();
和
public void insertFromJSONObject(JSONObject jsonObject, CircularImageView imageView, TextView textView) throws JSONException {
JSONArray dataArray = jsonObject.getJSONArray("data");
for (int i = 0; i < dataArray.length(); i++) {
JSONObject sectionObj = (JSONObject) dataArray.get(i);
JSONArray sectionsArray = sectionObj.getJSONArray("section");
for (int j = 0; j < sectionsArray.length(); j++) {
JSONObject obj = (JSONObject) sectionsArray.get(j);
Picasso.get().load(obj.getString("imag")).into(imageView);
mFragmentList.add(new TstFrag());
textView.setText(obj.getString("name"));
//mFragmentTitleList.add(obj.getString("name"));
notifyDataSetChanged();
}
}
}
这里的基本思想是为 FrgAdapter
的每个条目创建一个新的 TstFrag
实例。
考虑 NOT 手动将片段添加到 viewPager
,但只需在 viewPager 适配器上实现 getItem
&& instantiateItem
方法。然后 viewPager 将控制新 TstFrag
的 instantiation
或只是 重用创建的 之一。 检查此 。
@Override
public Fragment getItem(final int pos) {
return TstFrag.getInstance(dataList.get(pos));
}
@NonNull
@Override
public Object instantiateItem(ViewGroup container, int position) {
Fragment fragment = (Fragment) super.instantiateItem(container, position);
registeredFragments.put(position, fragment);
return fragment;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
registeredFragments.remove(position);
super.destroyItem(container, position, object);
}
更新
public class DataModel implements Serializable{
private String name;
private String image;
// GETTER && SETTER
}
替换
private List<String> mFragmentTitleList = new ArrayList<>();
与
private List<DataModel> dataList = new ArrayList<>();
insertFromJSONObject
dataList.clear();
for (int j = 0; j < sectionsArray.length(); j++) {
JSONObject obj = (JSONObject) sectionsArray.get(j);
final DataModel model = new DataModel();
model.setName(obj.getString("name"));
model.setImage(obj.getString("imag"));
// Picasso.get().load(obj.getString("imag")).into(imageView);
// No need to load image here just fetch for cache if you want.
Picasso.get().load(model.getImage()).fetch();
// mFragmentList.add(fragment); // no need handle adding fragment here as mentioned above.
dataList.add(dataModel);
// textView.setText(obj.getString("name")); // It's not good to update UI here but update there with fragment on create called mention below.
// notifyDataSetChanged(); DON'T call this inside the loop but after finish your stuff.
}
// Just notify here...
notifyDataSetChanged();
TstFrag
public class TstFrag extends Fragment {
private DataModel model;
public TstFrag() {
}
public static TstFrag getInstance(DataModel model){
TstFrag fragment = new TstFrag();
Bundle bundle = new Bundle();
bundle.putSerializable("mData", model);
fragment.setArguments(bundle);
return fragment;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
model = (DataModel)getArguments().getSerializable("mData");
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
final View rootView = inflater.inflate(R.layout.layout_cht, container, false);
// findViewById() for imageView and nameTextView
Picasso.get().load(model.getImage()).into(imageView);
nameTextView.setText(model.getName());
}}
我正在尝试向基于 TabLayout-ViewPager-Fragment
的应用程序添加选项卡 dynamically.The TabLayout
使用自定义视图,在 [=16= 之上有一个 ImageView
].
我现在想要的是根据从 PHP/MySQL 网络服务创建的 JSONArray
中的 JSONObjects
的数量添加选项卡。我在 PagerAdapter
中尝试了下面的方法,但它抛出:
java.lang.IllegalStateException: Can't change tag of fragment TstFrag{df80bc8 #0 id=0x7f080157 android:switcher:2131231063:0}: was android:switcher:2131231063:0 now android:switcher:2131231063:1
.
方法如下我的适配器
public class FrgAdapter extends FragmentStatePagerAdapter {
private List<Fragment> mFragmentList = new ArrayList<>();
private List<String> mFragmentTitleList = new ArrayList<>();
public FrgAdapter(FragmentManager fm) {
super(fm);
}
public FrgAdapter(FragmentManager fm, List<Fragment> mFragmentList, List<String> mFragmentTitleList) {
super(fm);
this.mFragmentList = mFragmentList;
this.mFragmentTitleList = mFragmentTitleList;
}
@Override
public Fragment getItem(int position) {
return mFragmentList.get(position);
}
@Override
public int getCount() {
return mFragmentList.size();
}
public void addFragment(Fragment fragment, String title) {
mFragmentList.add(fragment);
mFragmentTitleList.add(title);
}
public void insertFromJSONObject(JSONObject jsonObject, Fragment fragment, CircularImageView imageView, TextView textView) throws JSONException {
JSONArray dataArray = jsonObject.getJSONArray("data");
for (int i = 0; i < dataArray.length(); i++) {
JSONObject sectionObj = (JSONObject) dataArray.get(i);
JSONArray sectionsArray = sectionObj.getJSONArray("section");
for (int j = 0; j < sectionsArray.length(); j++) {
JSONObject obj = (JSONObject) sectionsArray.get(j);
Picasso.get().load(obj.getString("imag")).into(imageView);
mFragmentList.add(fragment);
mFragmentTitleList.add(obj.getString("name"));
textView.setText(obj.getString("name"));
notifyDataSetChanged();
}
}
}
@Override
public CharSequence getPageTitle(int position) {
return null;
}}
这里是在我的 activity 中调用方法来添加片段的地方:
private void setUpViewPager(ViewPager viewPager, View view) {
adapter = new FrgAdapter(getSupportFragmentManager());
/*adapter.addFragment(new MleFrag(), "Men");
adapter.addFragment(new FmlFrag(), "Women");
adapter.addFragment(new ChdFrag(), "Children");
adapter.addFragment(new AceFrag(), "Accessories");
*/
String url = "https://44091ee6.ngrok.io/Glam/men.json";
AndroidNetworking.get(url)
.setPriority(Priority.MEDIUM)
.build()
.getAsJSONObject(new JSONObjectRequestListener() {
@Override
public void onResponse(JSONObject response) {
try {
adapter.insertFromJSONObject(response, new TstFrag(), view.findViewById(R.id.circularImageView), view.findViewById(R.id.text_header));
adapter.notifyDataSetChanged();
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
public void onError(ANError anError) {
Toast.makeText(getApplicationContext(), anError.toString(), Toast.LENGTH_LONG).show();
}
});
adapter.notifyDataSetChanged();
viewPager.setAdapter(adapter);
}
这是我的Fragment
。在我看来,我想在每次需要时重复使用这个 Fragment
。
public class TstFrag extends Fragment {
public TstFrag() {
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.layout_cht, container, false);
}}
你可以试试这个:
adapter.insertFromJSONObject(response, view.findViewById(R.id.circularImageView), view.findViewById(R.id.text_header));
adapter.notifyDataSetChanged();
和
public void insertFromJSONObject(JSONObject jsonObject, CircularImageView imageView, TextView textView) throws JSONException {
JSONArray dataArray = jsonObject.getJSONArray("data");
for (int i = 0; i < dataArray.length(); i++) {
JSONObject sectionObj = (JSONObject) dataArray.get(i);
JSONArray sectionsArray = sectionObj.getJSONArray("section");
for (int j = 0; j < sectionsArray.length(); j++) {
JSONObject obj = (JSONObject) sectionsArray.get(j);
Picasso.get().load(obj.getString("imag")).into(imageView);
mFragmentList.add(new TstFrag());
textView.setText(obj.getString("name"));
//mFragmentTitleList.add(obj.getString("name"));
notifyDataSetChanged();
}
}
}
这里的基本思想是为 FrgAdapter
的每个条目创建一个新的 TstFrag
实例。
考虑 NOT 手动将片段添加到 viewPager
,但只需在 viewPager 适配器上实现 getItem
&& instantiateItem
方法。然后 viewPager 将控制新 TstFrag
的 instantiation
或只是 重用创建的 之一。 检查此
@Override
public Fragment getItem(final int pos) {
return TstFrag.getInstance(dataList.get(pos));
}
@NonNull
@Override
public Object instantiateItem(ViewGroup container, int position) {
Fragment fragment = (Fragment) super.instantiateItem(container, position);
registeredFragments.put(position, fragment);
return fragment;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
registeredFragments.remove(position);
super.destroyItem(container, position, object);
}
更新
public class DataModel implements Serializable{
private String name;
private String image;
// GETTER && SETTER
}
替换
private List<String> mFragmentTitleList = new ArrayList<>();
与
private List<DataModel> dataList = new ArrayList<>();
insertFromJSONObject
dataList.clear();
for (int j = 0; j < sectionsArray.length(); j++) {
JSONObject obj = (JSONObject) sectionsArray.get(j);
final DataModel model = new DataModel();
model.setName(obj.getString("name"));
model.setImage(obj.getString("imag"));
// Picasso.get().load(obj.getString("imag")).into(imageView);
// No need to load image here just fetch for cache if you want.
Picasso.get().load(model.getImage()).fetch();
// mFragmentList.add(fragment); // no need handle adding fragment here as mentioned above.
dataList.add(dataModel);
// textView.setText(obj.getString("name")); // It's not good to update UI here but update there with fragment on create called mention below.
// notifyDataSetChanged(); DON'T call this inside the loop but after finish your stuff.
}
// Just notify here...
notifyDataSetChanged();
TstFrag
public class TstFrag extends Fragment {
private DataModel model;
public TstFrag() {
}
public static TstFrag getInstance(DataModel model){
TstFrag fragment = new TstFrag();
Bundle bundle = new Bundle();
bundle.putSerializable("mData", model);
fragment.setArguments(bundle);
return fragment;
}
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
model = (DataModel)getArguments().getSerializable("mData");
}
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
final View rootView = inflater.inflate(R.layout.layout_cht, container, false);
// findViewById() for imageView and nameTextView
Picasso.get().load(model.getImage()).into(imageView);
nameTextView.setText(model.getName());
}}