即使我在使用FragmentStatePagerAdapter时返回POSITION_NONE，我也可以看到它删除了我的片段并创建了新实例。但是新实例接收带有旧片段状态的savedInstanceState Bundle。如何彻底销毁片段，以便Bundle在再次创建时为空？
请看这是我关于SOF的第一个问题，也许我没有遵循规则来提问，但我试图尽可能地回答我的问题。如果被要求，将要求提供更多指导并提供代码。
我的代码在这里： MyAdapter.java
public class MyAdapter extends FragmentStatePagerAdapter {
public static ArrayList<Integer> page_indexes = new ArrayList<>();
FragmentTransaction mCurTransaction = null;
FragmentManager mFragmentManager ;
private List<Fragment> mFragments ;
private Fragment dummyFragment;
//public static int CURRENT_ORDER_NO = 1;
public MyAdapter(FragmentManager fm) {
super(fm);
mFragmentManager=fm;
page_indexes.add(1);
}
@Override
public Fragment getItem(int position) {
Fragment fr = new FragmentAddOrder();
mFragments = mFragmentManager.getFragments();
for(int i=0;i<mFragments.size();i++){
}
Bundle args = new Bundle();
args.putInt("position", position);
fr.setArguments(args);
return fr;
}
@Override
public int getCount() {
return page_indexes.size();
}
@Override
public CharSequence getPageTitle(int position) {
return "ORDER #" + page_indexes.get(position);
}
@Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
public void deletePage(int position)
{
if(page_indexes.size()>0) {
page_indexes.remove(position);
//mFragmentManager.popBackStackImmediate();
notifyDataSetChanged();
mFragments = mFragmentManager.getFragments();
//FragmentTransaction trans = mFragmentManager.beginTransaction();
//trans.remove(mFragments.get(position));
//trans.commit();
}
}
}
HomeTabActivity.java
public class HomeTabActivity extends AppCompatActivity implements View.OnClickListener {
/**
* The current order number that helps iterate the present order number among various tabs made
*/
private int CURRENT_ORDER_NO = 1;
/**
* The pager widget, which handles animation and allows swiping horizontally to access previous
* and next wizard steps.
*/
public ViewPager mPager;
/**
* The pager adapter, which provides the pages to the view pager widget.
*/
MyAdapter mAdapter;
TabLayout tabLayout;
TextView tvTotalOrders;
private Boolean isFabOpen = false;
private FloatingActionButton fabMenu, fabPrint, fabDelete, fabAddCustomer;
private Animation fab_open, fab_close, rotate_forward, rotate_backward;
// public PagerAdapter mPagerAdapter;
// private ArrayList<Integer> page_indexes;
// int orderNumber = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home_tab);
mPager = (ViewPager) findViewById(R.id.container);
mAdapter = new MyAdapter(getSupportFragmentManager());
// mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager());
mPager.setAdapter(mAdapter);
tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
tabLayout.setupWithViewPager(mPager);
tvTotalOrders = (TextView) findViewById(R.id.totalOrders);
fab_close = AnimationUtils.loadAnimation(this, R.anim.fab_close);
fab_open = AnimationUtils.loadAnimation(this, R.anim.fab_open);
rotate_backward = AnimationUtils.loadAnimation(this, R.anim.rotate_backward);
rotate_forward = AnimationUtils.loadAnimation(this, R.anim.rotate_forward);
tvTotalOrders.setText("Orders Running: " + MyAdapter.page_indexes.size());
fabMenu = (FloatingActionButton) findViewById(R.id.fabMenu);
fabPrint = (FloatingActionButton) findViewById(R.id.fabPrint);
fabDelete = (FloatingActionButton) findViewById(R.id.fabDelete);
fabAddCustomer = (FloatingActionButton) findViewById(R.id.fabAddCustomer);
fabMenu.setOnClickListener(this);
fabPrint.setOnClickListener(this);
fabDelete.setOnClickListener(this);
fabAddCustomer.setOnClickListener(this);
//page_indexes = new ArrayList<>();
mPager.setOffscreenPageLimit(5);
/*mAdapter.deletePage(mPager.getCurrentItem());*/
}
/**
* Author Vibhu Jain
* Date Created : 11 July 2017
* Date Last Modified : 11 July 2017
* Desc : This Function is responsible to inflate options menu in the ActionBar/ToolBar of the activity.
* <p>
* Last Modification:
*/
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.mymenu, menu);
return super.onCreateOptionsMenu(menu);
}
/**
* Author Vibhu Jain
* Date Created : 10 July 2017
* Date Last Modified : 11 July 2017
* Desc : This Function is responsible for onOptions Items actions performed
* when a certain action is selected on ActionBar OptionsMenu.
* <p>
* Last Modification: Added setText statement for No. of Orders running
*/
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.addTab) {
CURRENT_ORDER_NO += 1;
MyAdapter.page_indexes.add(CURRENT_ORDER_NO);
tvTotalOrders.setText("Orders Running: " + MyAdapter.page_indexes.size());
mAdapter.notifyDataSetChanged();
// do something here
}
if (id == R.id.printAll) {
Intent webviewIntent = new Intent(this, WebviewDemoActivity.class);
startActivity(webviewIntent);
}
return super.onOptionsItemSelected(item);
}
/**
* Author Vibhu Jain
* Date Created : 11 July 2017
* Date Last Modified : 13 July 2017
* Desc : This Function is responsible for onClick actions performed
* while clicking of Floating Action Buttons Group.
* <p>
* Last Modification: Added fabAddCustomer in the group with necessary onClick action as asked by Sunit Kumar.
* Added call to webview to generate print for each order
*/
@Override
public void onClick(View view) {
int id = view.getId();
switch (id) {
case R.id.fabMenu:
animateFAB();
break;
case R.id.fabPrint:
Intent webviewIntent = new Intent(this, WebviewDemoActivity.class);
webviewIntent.putExtra("OrderNo",""+(mPager.getCurrentItem()+1)); //Toast.makeText(this,""+mPager.getCurrentItem()+1,Toast.LENGTH_LONG).show();
startActivity(webviewIntent);
break;
case R.id.fabDelete:
//mPager.removeViewAt(mPager.getCurrentItem());
//mPager.setCurrentItem(mPager.getCurrentItem()-1);
mAdapter.deletePage(mPager.getCurrentItem());
//mPager.setAdapter(mAdapter);
tvTotalOrders.setText("Orders Running: " + MyAdapter.page_indexes.size());
break;
case R.id.fabAddCustomer:
Intent intentDialogActivity = new Intent(getApplicationContext(), ActivityDialogCustomerAdd.class);
startActivity(intentDialogActivity);
}
}
}
FragmentAddOrder.java
public class FragmentAddOrder extends Fragment {
ArrayList<String> itemsList = new ArrayList<>();
ArrayList<Integer> quantity = new ArrayList<>();
ArrayList<Double> price = new ArrayList<>();
/**
* Declaring an ArrayAdapter to set items to ListView
*/
ArrayAdapter<String> adapter;
AutoCompleteTextView textProductView;
TextView txtEmpty;
EditText itemQuantity;
String selectedItem = "";
InputMethodManager inputMethodManager;
public static final int REQUEST_CODE = 6;
int positionNum = 1;
int positionNumSIS;
int intItemQuantity = 0;
double doubleProductPrice = 0;
@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
positionNum = getArguments() != null ? getArguments().getInt("position") : 1;
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
setRetainInstance(false);
return inflater.inflate(
R.layout.activity_main, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
txtEmpty = view.findViewById(R.id.txtEmpty);
if (savedInstanceState != null) {
//probably orientation change
positionNumSIS = (int) savedInstanceState.getSerializable("positionNum");
if (positionNumSIS == positionNum) {
itemsList = (ArrayList<String>) savedInstanceState.getSerializable("itemsList");
quantity = (ArrayList<Integer>) savedInstanceState.getSerializable("quantityList");
price = (ArrayList<Double>) savedInstanceState.getSerializable("priceList");
if (itemsList.size() >= 1) {
txtEmpty.setText("Total Items: " + itemsList.size());
}
}
}
//Rest of the work is my Fragment's Work to do with
}
/**
* Author Vibhu Jain
* Date Created : 11 July 2017
* Date Last Modified : 12 July 2017
* Desc : This Function is responsible for saving up the Fragment's List items so that they persist when a new tab is added
* or an existing tab is deleted.
* <p>
* Last Modification: Added positionNum for testing purposes
*/
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putSerializable("itemsList", (Serializable) itemsList);
outState.putSerializable("quantityList", (Serializable) quantity);
outState.putSerializable("priceList", (Serializable) price);
outState.putSerializable("positionNum", positionNum);
}
//This function is not so usable for now, can be ignored
@Override
public void onDetach() {
super.onDetach();
if (this.isRemoving()) {
FragmentManager fm = getFragmentManager();
fm.beginTransaction().remove(this).commitAllowingStateLoss();
}
}
}
基本上，我要做的是在viewpager中添加一些标签以获取一些订单。在添加更多选项卡的同时，保留其他选项卡中的持续数据。 如果需要删除某个选项卡，则应将其与其捆绑状态一起删除，以便其他片段（在选项卡中）不会受到影响并保留其数据。
但是现在，当我尝试删除我的标签时，它只是将标签替换为标签位置向前，并在下一个标签中移动现有片段的数据。
希望这能澄清我的问题，如果需要任何其他代码/帮助，我会立即回复。