API 24的TabLayout更新了一些方法 用著有些問(wèn)題 比如像我遇到的自定義處理某些tab點(diǎn)擊時(shí)想要不切換viewPager 而是彈出一個(gè)activity
下面是一個(gè)簡(jiǎn)單的懶人處理方式 附帶源碼分析

ViewPager vp = (ViewPager)findViewById(R.id.viewPager);
TabLayout tabLayout = (TabLayout)findViewById(R.id.tabLayout);
tabLayout.setupWithViewPager(vp);//看看這個(gè)方法做了什么

private void setupWithViewPager(@Nullable final ViewPager viewPager, boolean autoRefresh,
            boolean implicitSetup) {
        if (mViewPager != null) {
            // If we've already been setup with a ViewPager, remove us from it
            if (mPageChangeListener != null) {
                mViewPager.removeOnPageChangeListener(mPageChangeListener);
            }
            if (mAdapterChangeListener != null) {
                mViewPager.removeOnAdapterChangeListener(mAdapterChangeListener);
            }
        }


        if (mCurrentVpSelectedListener != null) {
            // If we already have a tab selected listener for the ViewPager, remove it
            removeOnTabSelectedListener(mCurrentVpSelectedListener);
            mCurrentVpSelectedListener = null;
        }


        if (viewPager != null) {
            mViewPager = viewPager;


            // Add our custom OnPageChangeListener to the ViewPager
            if (mPageChangeListener == null) {
                mPageChangeListener = new TabLayoutOnPageChangeListener(this);
            }
            mPageChangeListener.reset();
            viewPager.addOnPageChangeListener(mPageChangeListener);


            // Now we'll add a tab selected listener to set ViewPager's current item
            mCurrentVpSelectedListener = new ViewPagerOnTabSelectedListener(viewPager);
            addOnTabSelectedListener(mCurrentVpSelectedListener);//這里給你添加了一個(gè)OnTabSelectedListener


            final PagerAdapter adapter = viewPager.getAdapter();
            if (adapter != null) {
                // Now we'll populate ourselves from the pager adapter, adding an observer if
                // autoRefresh is enabled
                setPagerAdapter(adapter, autoRefresh);
            }


            // Add a listener so that we're notified of any adapter changes
            if (mAdapterChangeListener == null) {
                mAdapterChangeListener = new AdapterChangeListener();
            }
            mAdapterChangeListener.setAutoRefresh(autoRefresh);
            viewPager.addOnAdapterChangeListener(mAdapterChangeListener);


            // Now update the scroll position to match the ViewPager's current item
            setScrollPosition(viewPager.getCurrentItem(), 0f, true);
        } else {
            // We've been given a null ViewPager so we need to clear out the internal state,
            // listeners and observers
            mViewPager = null;
            setPagerAdapter(null, false);
        }


        mSetupViewPagerImplicitly = implicitSetup;
    }

看上面的源碼你會(huì)發(fā)現(xiàn) 這個(gè)方法里 TabLayout會(huì)幫你add一個(gè)OnTabSelectedListener 就是下面這個(gè)

class ViewPagerOnTabSelectedListener implements TabLayout.OnTabSelectedListener {
        private final ViewPager mViewPager;


        public ViewPagerOnTabSelectedListener(ViewPager viewPager) {
            mViewPager = viewPager;
        }


        @Override
        public void onTabSelected(TabLayout.Tab tab) {
            mViewPager.setCurrentItem(tab.getPosition());//強(qiáng)行幫你選中你不希望選中的viewPager的某個(gè)頁(yè)面
        }


        @Override
        public void onTabUnselected(TabLayout.Tab tab) {
            // No-op
        }


        @Override
        public void onTabReselected(TabLayout.Tab tab) {
            // No-op
        }
    }

然后罪魁禍?zhǔn)资荰abLayout的這個(gè)方法 從上面可以看出來(lái) 在你addOnTabSelectedListener之前已經(jīng)有一個(gè)OnTabSelectedListener了
所以 執(zhí)行完你自己加的OnTabSelectedListener的onTabSelected之后 總會(huì)執(zhí)行TabLayout會(huì)幫你add那個(gè)OnTabSelectedListener的onTabSelected

private void dispatchTabSelected(@NonNull final Tab tab) {
    for (int i = mSelectedListeners.size() - 1; i >= 0; i--) {
        mSelectedListeners.get(i).onTabSelected(tab);
    }
}

所以 我想到的解決方案是強(qiáng)行remove掉它給你加的那個(gè)OnTabSelectedListener 可以 這很反射 當(dāng)然 你要換成github上的一些TabLayout也無(wú)妨

Field fields[] = tabLayout.getClass().getDeclaredFields();
String[] name = new String[fields.length];
Object[] value = new Object[fields.length];


try {
    Field.setAccessible(fields, true);
    for (int i = 0; i < name.length; i++) {
        name[i] = fields[i].getName();
        value[i] = fields[i].get(tabLayout);
        if (name[i].equals("mCurrentVpSelectedListener")) {
            tabLayout.removeOnTabSelectedListener((TabLayout.OnTabSelectedListener) value[i]);
        }
    }
} catch (Exception e) {
    e.printStackTrace();
}

然后自定義自己的OnTabSelectedListener

OnTabSelectedListener mTabSelectedListener = new TabLayout.ViewPagerOnTabSelectedListener(vp) {


    @Override
    public void onTabSelected(TabLayout.Tab tab) {
        int position = (int) tab.getTag();
        if (position == 0) {
            vp.setCurrentItem(tab.getPosition());
        }else if (position == 1) {
            if (condition) {//condition：自己寫(xiě)的某些條件
                if (tab != null) {
                    vp.setCurrentItem(tab.getPosition());//手動(dòng)調(diào)用viewPager的setCurrentItem
                }
            } else {
                doSomething();//可以做些其他事情 這里不用調(diào)用viewPager的setCurrentItem 就不會(huì)切到不想切換的viewPager那個(gè)頁(yè)面了
            }
        }
    }


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


    @Override
    public void onTabReselected(TabLayout.Tab tab) {
    //之所以要在這里添加reslect的處理 主要是你之前點(diǎn)擊tab的時(shí)候雖然沒(méi)選中并切換Viewpager的頁(yè)面
    //但是 TabLayout的狀態(tài)其實(shí)已經(jīng)被選中了 再次點(diǎn)擊時(shí)肯定是不會(huì)走onTabSelected方法的
    //但是會(huì)走這個(gè)onTabReselected 另外 選中時(shí)一些UI上的圖標(biāo)、文字切換效果什么的需要自己在onTabSelected中處理 
        int position = (int) tab.getTag();
        L.e(TAG, position + " onTabReselected");
        mTabSelectedListener.onTabSelected(tab);
    }
};

最后addOnTabSelectedListener

tabLayout.addOnTabSelectedListener(mTabSelectedListener);

release版本開(kāi)了混淆的話在proguard-rules.pro加上

-keepclasseswithmembernames class android.support.design.widget.TabLayout {
    *;
}