如何在android中使用viewpager动态创建tab？ [英] How can i create dynamically tab with viewpager in android?

问题描述

说明：

假设我有多个类别来自我的REST。我不知道有多少类别是5,7或有时2等。我想用viewpager将所有类别放在我的选项卡上。我想根据类别大小创建一个选项卡。让我们看看，例如假设在我的REST响应中只有2个类别，它只创建两个选项卡。如果它有5个类别，那么5个标签，依此类推。

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.

以下是创建标签的示例测试示例。

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);
    }
}

请问，我该如何解决？

推荐答案

获得类别大小后，您可以根据类别大小添加动态标签，如下所示：

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) {

        }
    });


   }
}

和你的适配器类应如下所示：

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);
}
}

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