在选项卡布局中选择选项卡后，如何每次获取选项卡位置？

Question

我是标签布局 material 设计的新手。每次选择选项卡后如何获取选项卡的位置。我正在使用以下代码。

 tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                Toast.makeText(getApplicationContext(),"Pos onTabSelected: "+tab.getPosition(),Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {
            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {
            }
        });

通过使用此代码，我只能获得第一个制表符位置（仅一次）。我想每次选择标签后得到位置。

完整代码：

package info.androidhive.materialtabs.activity;

import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

import info.androidhive.materialtabs.R;
import info.androidhive.materialtabs.fragments.OneFragment;
import info.androidhive.materialtabs.fragments.ThreeFragment;
import info.androidhive.materialtabs.fragments.TwoFragment;

public class SimpleTabsActivity extends AppCompatActivity {

    private Toolbar toolbar;
    private TabLayout tabLayout;
    private ViewPager viewPager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_simple_tabs);

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        viewPager = (ViewPager) findViewById(R.id.viewpager);
        setupViewPager(viewPager);

        tabLayout = (TabLayout) findViewById(R.id.tabs);
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                Toast.makeText(getApplicationContext(),"Pos onTabSelected: "+ tabLayout.getSelectedTabPosition(),Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onTabUnselected(TabLayout.Tab tab) {
            }

            @Override
            public void onTabReselected(TabLayout.Tab tab) {
            }
        });
        tabLayout.setupWithViewPager(viewPager);
    }

    private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.addFragment(new OneFragment(), "ONE");
        adapter.addFragment(new TwoFragment(), "TWO");
        adapter.addFragment(new ThreeFragment(), "THREE");
        viewPager.setAdapter(adapter);
    }

    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);
        }
    }
}

Answer 1

tab.getPosition()用于获取当前选中的tab位置。

在调用 setOnTabSelectedListener 之前添加以下代码

tabLayout.setupWithViewPager(viewPager);

它将正常工作。

在选项卡布局中选择选项卡后，如何每次获取选项卡位置？

How to get tab position every time after selecting the tab in tab layout?

android

tabs

android-tablayout