如果你知道你想要选择的标签的索引，你可以这样做:

TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
TabLayout.Tab tab = tabLayout.getTabAt(someIndex);
tab.select();

即使你使用TabLayout本身而没有ViewPager(这是非典型的，可能是不好的做法，但我见过这样做)，这种技术也是有效的。

这可能不是最终的解决方案，它需要你使用TabLayout和一个ViewPager，但这是我解决它的方法:

void selectPage(int pageIndex)
{
    viewPager.setCurrentItem(pageIndex);
    tabLayout.setupWithViewPager(viewPager);
}

我测试了使用这段代码对性能的影响有多大，首先在Android Studio中运行该方法时查看CPU和内存监视器，然后将其与我自己在页面之间导航时(使用滑动手势)对CPU和内存的负载进行比较，结果发现差异并不大，所以至少这不是一个可怕的解决方案……

希望这能帮助到一些人!

我是这样解决的:

void selectPage(int pageIndex){
    tabLayout.setScrollPosition(pageIndex,0f,true);
    viewPager.setCurrentItem(pageIndex);
}

如果你不能使用tab.select()，也不想使用ViewPager，你仍然可以通过编程方式选择一个选项卡。如果你通过TabLayout使用自定义视图。选项卡setCustomView (android.view。View View)它更简单。以下是如何做到这两种方式。

// if you've set a custom view
void updateTabSelection(int position) {
    // get the position of the currently selected tab and set selected to false
    mTabLayout.getTabAt(mTabLayout.getSelectedTabPosition()).getCustomView().setSelected(false);
    // set selected to true on the desired tab
    mTabLayout.getTabAt(position).getCustomView().setSelected(true);
    // move the selection indicator
    mTabLayout.setScrollPosition(position, 0, true);

    // ... your logic to swap out your fragments
}

如果你不使用自定义视图，那么你可以这样做

// if you are not using a custom view
void updateTabSelection(int position) {
    // get a reference to the tabs container view
    LinearLayout ll = (LinearLayout) mTabLayout.getChildAt(0);
    // get the child view at the position of the currently selected tab and set selected to false
    ll.getChildAt(mTabLayout.getSelectedTabPosition()).setSelected(false);
    // get the child view at the new selected position and set selected to true
    ll.getChildAt(position).setSelected(true);
    // move the selection indicator
    mTabLayout.setScrollPosition(position, 0, true);

    // ... your logic to swap out your fragments
}

使用StateListDrawable在选中和未选中的可绘制对象之间切换，或者类似地处理颜色和/或可绘制对象。

默认情况下，如果你选择一个选项卡，它将高亮显示。如果你想选择显式意味着使用给定的注释代码在onTabSelected(TabLayout。标签标签)与您指定的标签索引位置。这段代码将解释使用viewpager在选项卡选择位置上更改片段。

public class GalleryFragment extends Fragment implements TabLayout.OnTabSelectedListener 
{
private ViewPager viewPager;public ViewPagerAdapter adapter;private TabLayout tabLayout;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_gallery, container, false);
viewPager = (ViewPager) rootView.findViewById(R.id.viewpager);
adapter = new ViewPagerAdapter(getChildFragmentManager());
adapter.addFragment(new PaymentCardFragment(), "PAYMENT CARDS");
adapter.addFragment(new LoyaltyCardFragment(), "LOYALTY CARDS");
viewPager.setAdapter(adapter);
tabLayout = (TabLayout) rootView.findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(viewPager);
    tabLayout.setOnTabSelectedListener(this);
}

@Override
public void onTabSelected(TabLayout.Tab tab) {
    //This will be called 2nd when you select a tab or swipe using viewpager
    final int position = tab.getPosition();
    Log.i("card", "Tablayout pos: " + position);
    //TabLayout.Tab tabdata=tabLayout.getTabAt(position);
    //tabdata.select();
    tabLayout.post(new Runnable() {
        @Override
        public void run() {
            if (position == 0) {
                PaymentCardFragment paymentCardFragment = getPaymentCardFragment();
                if (paymentCardFragment != null) {
                   VerticalViewpager vp = paymentCardFragment.mypager;
                    if(vp!=null)
                    {
                      //vp.setCurrentItem(position,true);
                      vp.setCurrentItem(vp.getAdapter().getCount()-1,true);
                    }
                  }
            }
            if (position == 1) {
               LoyaltyCardFragment loyaltyCardFragment = getLoyaltyCardFragment();
                if (loyaltyCardFragment != null) {
                   VerticalViewpager vp = loyaltyCardFragment.mypager;
                    if(vp!=null)
                    {
                        vp.setCurrentItem(position);
                    }
                  }
            }
        }
    });
}

@Override
public void onTabUnselected(TabLayout.Tab tab) {
 //This will be called 1st when you select a tab or swipe using viewpager
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
  //This will be called only when you select the already selected tab(Ex: selecting 3rd tab again and again)
}
 private PaymentCardFragment getLoyaltyCardFragment() {
    Fragment f = adapter.mFragmentList.get(viewPager.getCurrentItem());

   if(f instanceof PaymentCardFragment)
   {
    return (PaymentCardFragment) f;
   }
   return null;
 }
private LoyaltyCardFragment getPaymentCardFragment() {
    Fragment f = adapter.mFragmentList.get(viewPager.getCurrentItem());
    if(f instanceof LoyaltyCardFragment)
   {
    return (LoyaltyCardFragment) f;
   }
   return null;
 }
  class ViewPagerAdapter extends FragmentPagerAdapter {
   public List<Fragment> mFragmentList = new ArrayList<>();
    private final List<String> mFragmentTitleList = new ArrayList<>();
   public void addFragment(Fragment fragment, String title) {
   mFragmentList.add(fragment);
   mFragmentTitleList.add(title);
  }
 }
}

用这个:

tabs.getTabAt(index).select();

请记住，如果currentTabIndex和index是相同的，那么这将发送您的流到onTabReselected而不是onTabSelected。

为你的viewpager添加:

 viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                array.clear();
                switch (position) {
                    case 1:
                        //like a example
                        setViewPagerByIndex(0);
                        break;
                }
            }

            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            }

            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });

//on处理程序，以防止crash outofmemory

private void setViewPagerByIndex(final int index){
    Application.getInstance().getHandler().post(new Runnable() {
        @Override
        public void run() {
            viewPager.setCurrentItem(index);
        }
    });
}

试试这个

    new Handler().postDelayed(
            new Runnable(){
                @Override
                public void run() {
                    if (i == 1){
                        tabLayout.getTabAt(0).select();
                    } else if (i == 2){
                        tabLayout.getTabAt(1).select();
                    }
                }
            }, 100);

用这个:

<android.support.design.widget.TabLayout
    android:id="@+id/patienthomescreen_tabs"
    android:layout_width="match_parent"
    android:layout_height="72sp"
    app:tabGravity="fill"
    app:tabMode="fixed"
    app:tabIndicatorColor="@android:color/white"
    app:tabSelectedTextColor="@color/green"/>

在OnClickListener中:

TabLayout tabLayout = (TabLayout) findViewById(R.id.patienthomescreen_tabs);
TabLayout.Tab tab = tabLayout.getTabAt(someIndex);
tab.select();

请记住，如果currentTabIndex和index是相同的，那么这将发送您的流到onTabReselected而不是onTabSelected。

我使用TabLayout切换片段。它在大多数情况下都是有效的，除了当我试图以编程方式使用tab.select()，我的TabLayout选择一个选项卡时。OnTabSelectedListener将触发onTabSelected(TabLayout。Tab Tab)，这会让我很伤心。我正在寻找一种不触发侦听器的方法来做程序化选择。

So I adapted @kenodoggy 's answer to my use. I was further facing a problem where some of the internal objects would return null (because they weren't created yet, because I was answering onActivityResult() from my fragment, which occurs before onCreate() in the case the activity is singleTask or singleInstance) so I wrote up a detailed if/else sequence which would report the error and fall through without the NullPointerException that would otherwise trigger. I use Timber for logging, if you're not using that substitute with Log.e().

void updateSelectedTabTo(int position) {
    if (tabLayout != null){
        int selected = tabLayout.getSelectedTabPosition();
        if (selected != -1){
            TabLayout.Tab oldTab = tabLayout.getTabAt(0);
            if (oldTab != null){
                View view = oldTab.getCustomView();
                if (view != null){
                    view.setSelected(false);
                }
                else {
                    Timber.e("oldTab customView is null");
                }
            }
            else {
                Timber.e("oldTab is null");
            }
        }
        else {
            Timber.e("selected is -1");
        }
        TabLayout.Tab newTab = tabLayout.getTabAt(position);
        if (newTab != null){
            View view = newTab.getCustomView();
            if (view != null){
                view.setSelected(false);
            }
            else {
                Timber.e("newTab customView is null");
            }
        }
        else {
            Timber.e("newTab is null");
        }
    }
    else {
        Timber.e("tablayout is null");
    }
}

这里，tabLayout是绑定到XML中的tabLayout对象的内存变量。我不使用滚动标签功能，所以我把它也删除了。

你可以试着用这个来解决:

TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(mViewPager);

TabLayout.Tab tab = tabLayout.getTabAt(pos);
if (tab != null) {
    tab.select();
}

这也有帮助

viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
    @Override
    public void onPageScrolled(int i, float v, int i1) {
    }

    @Override
    public void onPageSelected(int i) {
        tablayout.getTabAt(i).select();
    }

    @Override
    public void onPageScrollStateChanged(int i) {
    }
});

只需设置viewpage . setcurrentitem (index)和相关的TabLayout将选择各自的选项卡。

您可以使用以下函数设置TabLayout位置

public void setTab(){
 tabLayout.setScrollPosition(YOUR_SCROLL_INDEX,0,true);
 tabLayout.setSelected(true);
}

如果碰巧你的默认选项卡是第一个(0)，而你碰巧切换到一个片段，那么你必须手动替换第一次的片段。这是因为在注册侦听器之前选择了选项卡。

private TabLayout mTabLayout;

...

@Override
public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_tablayout, container, false);
    mTabLayout = view.findViewById(R.id.sliding_tabs);
    mTabLayout.addOnTabSelectedListener(mOnTabSelectedListener);

    getActivity().getSupportFragmentManager().beginTransaction()
        .replace(R.id.tabContent, MyFirstFragment.newInstance()).commit();
    return view;
}

或者，你可以考虑调用getTabAt(0).select()并像这样重写onTabReselected:

@Override
public void onTabReselected(TabLayout.Tab tab) {
    // Replace the corresponding tab fragment.
}

这是可行的，因为你实际上是在每个选项卡重新选择上替换片段。

如果您在理解上有困难，这段代码可以帮助您

private void MyTabLayout(){
    TabLayout.Tab myTab = myTabLayout.newTab(); // create a new tab
    myTabLayout.addTab(myTab); // add my new tab to myTabLayout
    myTab.setText("new tab"); 
    myTab.select(); // select the new tab
}

你也可以在你的代码中添加这个:

myTabLayout.setTabTextColors(getColor(R.color.colorNormalTab),getColor(R.color.colorSelectedTab));

试试这个方法。

tabLayout.setTabTextColors(getResources().getColor(R.color.colorHintTextLight),
                           getResources().getColor(R.color.colorPrimaryTextLight));

如果你使用TabLayout没有viewPager，这有助于

 mTitles = getResources().getStringArray(R.array.tabItems);
    mIcons = getResources().obtainTypedArray(R.array.tabIcons);
    for (int i = 0; i < mTitles.length; i++) {

        tabs.addTab(tabs.newTab().setText(mTitles[i]).setIcon(mIcons.getDrawable(i)));
        if (i == 0) {
            /*For setting selected position 0 at start*/
            Objects.requireNonNull(Objects.requireNonNull(tabs.getTabAt(i)).getIcon()).setColorFilter(ContextCompat.getColor(getApplicationContext(), R.color.colorPrimary), PorterDuff.Mode.SRC_IN);
        }
    }

    tabs.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            Objects.requireNonNull(tab.getIcon()).setColorFilter(ContextCompat.getColor(getApplicationContext(), R.color.colorPrimary), PorterDuff.Mode.SRC_IN);
        }

        @Override
        public void onTabUnselected(TabLayout.Tab tab) {
            Objects.requireNonNull(tab.getIcon()).setColorFilter(ContextCompat.getColor(getApplicationContext(), R.color.white), PorterDuff.Mode.SRC_IN);
        }

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

        }
    });

有点晚了，但可能是一个有用的解决方案。 我直接在我的片段中使用我的TabLayout，并试图在片段的生命周期中选择一个选项卡。 对我来说有用的是等待TabLayout使用android.view绘制完它的子视图。视图# post方法。即:

int myPosition = 0;
myFilterTabLayout.post(() -> { filterTabLayout.getTabAt(myPosition).select(); });

结合不同的答案可以得出:

new Handler().postDelayed(() -> {
  myViewPager.setCurrentItem(position, true);
  myTabLayout.setScrollPosition(position, 0f, true);
},
100);

你应该使用viewPager来使用viewpage . setcurrentitem ()

 viewPager.setCurrentItem(n);
 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) {

            }
        });

对于材质组件库提供的TabLayout，只需使用selectTab方法:

TabLayout tabLayout = findViewById(R.id.tab_layout);
tabLayout.selectTab(tabLayout.getTabAt(index));

它需要版本为1.1.0。

科特林修复

viewPager.currentItem = 0

tabs.setupWithViewPager（viewPager）

TabLayout jobTabs = v.findViewById(R.id.jobTabs);
ViewPager jobFrame = v.findViewById(R.id.jobPager);
jobFrame.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(jobTabs));

这将选择标签作为视图分页器滑动页面

如果你正在使用TabLayout和viewPager，那么这有助于你。你可以在addOnpagelistener中使用ViewPager设置TabLayout。

如果你想直接设置TabLayout的位置(不是点击Tab个人)试试下面的代码TabLayout . gettabat (position_you_want_to_set).select()

   /* will be invoked whenever the page changes or is incrementally scrolled*/
    viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        }

        @Override
        public void onPageSelected(int position) {
            tabLayout.getTabAt(position).select();
        }

        @Override
        public void onPageScrollStateChanged(int state) {

        }
    });

这将不工作的应用程序，有ViewPager2实现，为此，你需要使用

viewPager2.setCurrentItem(position);

当我们使用TabLayoutMediator时，在onConfigureTab中找到onConfigureTab

i.e

TabLayoutMediator tabLayoutMediator = new TabLayoutMediator(
                tabLayout, viewPager2, new TabLayoutMediator.TabConfigurationStrategy() {
            @Override
            public void onConfigureTab(@NonNull TabLayout.Tab tab, int position) {
                switch (position){
                    case 0 : tab.setIcon(getResources().getDrawable(R.drawable.camera));
                            break;
                    case 1 : tab.setText("CHAT");
                            viewPager2.setCurrentItem(position); // when app starts this will be the selected tab
                            break;
                    case 2 : tab.setText("STATUS");
                            break;
                    case 3 : tab.setText("CALL");
                        break;
                }
            }
        }
        );
        tabLayoutMediator.attach();

Kotlin \用户:

Handler(Looper.getMainLooper()).postDelayed(
            { tabLayout.getTabAt(position).select() }, 100
        )

这也将滚动你的标签布局，如果它需要滚动。

对于Viewpager2, Kotlin，其他答案都没有帮助，只有下面这个有用。位置是从片段结果监听器在我的情况下:

TabLayoutMediator(binding.tabLayout, binding.viewPager2) { _, _ ->
    binding.viewPager2 = position
}.attach()

最新的简单解决方案对我很有效:

binding.tablayout.selectTab(binding.tablayout.getTabAt(tabPosisiton))

or

with(binding.tablayout) {
    selectTab(getTabAt(tabPosisiton))
}

和tabPosition从0开始