How can i create dynamically tab with viewpager in android?

问题:

Explanation:

Suppose, I have multiple categories which come from my REST. I don't know how many categories it's mat be 5,7 or sometimes 2 etc. I want to put all the categories on my tab with viewpager. I want to create a tab accordingly to the categories size. let's see e.g. suppose in my REST response have only 2 categories it's create only two tab. if it have 5 categories then 5 tab and so on.

Here is the sample test example to create a tabs.

MainActivity.java

public class MainActivity extends AppCompatActivity {      TabLayout tabLayout;     ViewPager viewPager;     Toolbar toolbar;     @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         setContentView(R.layout.activity_main);          toolbar=(Toolbar)findViewById(R.id.toolbar);         setSupportActionBar(toolbar);          tabLayout=(TabLayout)findViewById(R.id.tabs);         viewPager=(ViewPager)findViewById(R.id.viewpager);          setupViewPager(viewPager);         viewPager.setCurrentItem(0);         tabLayout.setupWithViewPager(viewPager);     }     private void setupViewPager(ViewPager viewPager) {         ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());         for(int i=0;i<3;i++){             adapter.addFragment(new OneFragment(), "ONE"); //            adapter.addFragment(new TwoFragment(), "TWO");             viewPager.setAdapter(adapter);         }     } } 

ViewPagerAdapter.java

public class ViewPagerAdapter extends FragmentPagerAdapter {      private final List<Fragment> mFragmentList = new ArrayList<>();     private final List<String> mFragmentTitleList = new ArrayList<>();      public ViewPagerAdapter(FragmentManager manager){         super(manager);     }      @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);     }      @Override     public CharSequence getPageTitle(int position) {         return mFragmentTitleList.get(position);     } } 

Please, How can I solve out???

回答1:

After you get categories size, you can add dynamic tabs as per your categories size as below:

public class MainActivity extends AppCompatActivity {  TabLayout tabLayout; ViewPager viewPager; Toolbar toolbar; int no_of_categories=-1;  @Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);     setContentView(R.layout.activity_main);      toolbar=(Toolbar)findViewById(R.id.toolbar);     setSupportActionBar(toolbar);      tabLayout=(TabLayout)findViewById(R.id.tabs);     viewPager=(ViewPager)findViewById(R.id.viewpager);      no_of_categories=YOUR_NO_CATEGORIES;      for (int i = 0; i < no_of_weeks; i++) {         tabLayout.addTab(tabLayout.newTab().setText("TAB " + String.valueOf(i + 1)));     }      ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager(),tabLayout.getTabCount());     viewPager.setAdapter(adapter);      tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {         @Override         public void onTabSelected(TabLayout.Tab tab) {              viewPager.setCurrentItem(tab.getPosition());         }          @Override         public void onTabUnselected(TabLayout.Tab tab) {          }          @Override         public void onTabReselected(TabLayout.Tab tab) {          }     });      } } 

And your Adapter Class should be like below:

public class ViewPagerAdapterextends FragmentStatePagerAdapter { int mNumOfTabs; Fragment fragment = null;  public ViewPagerAdapter(FragmentManager fm, int NumOfTabs) {     super(fm);     this.mNumOfTabs = NumOfTabs; }  @Override public Fragment getItem(int position) {      for (int i = 0; i < mNumOfTabs ; i++) {         if (i == position) {             fragment = YourFragment.newInstance();             break;         }     }     return fragment;  }  @Override public int getCount() {     return mNumOfTabs; }  @Override public CharSequence getPageTitle(int position) {     return super.getPageTitle(position); } } 

回答2:

if I were you I would try something like this:

its not a perfect solution just an idea of how you can do it, you would need to further modify it.

Create number of fagments = total number of categeries and name them like fragment0, fragment1 so on to the total number of categeries.

and then get the number of categeries first lets say

int count = number of categeries; 

and then add fragments to ViewPager like this

ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());     for(int i=0; i <= count; i++){         adapter.addFragment(new Fragment(i)(), "ONE");         viewPager.setAdapter(adapter);     } } 

and to name the fragments i.e tab title you can make list of fragment titles, something like this

private final String[] title = {"One", "Two","Three"};  ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());         for(int i=0; i < count; i++){             adapter.addFragment(new Fragment(i)(), title[i]);             viewPager.setAdapter(adapter);         }     } 

I hope it helps

文章来源: How can i create dynamically tab with viewpager in android?