public void reflex(final TabLayout tabLayout) {
    //了解源码得知 线的宽度是根据 tabView的宽度来设置的
        tabLayout.post(new Runnable() {
            @Override
            public void run() {
                try {
                    //拿到tabLayout的mTabStrip属性
                    LinearLayout mTabStrip = (LinearLayout) tabLayout.getChildAt(0);
                    int dp10 = dip2px(tabLayout.getContext(), 10);
                    for (int i = 0; i < mTabStrip.getChildCount(); i++) {
                        View tabView = mTabStrip.getChildAt(i);
                        //拿到tabView的mTextView属性  tab的字数不固定一定用反射取mTextView
                        Field mTextViewField = tabView.getClass().getDeclaredField("mTextView");
                        mTextViewField.setAccessible(true);
                        TextView mTextView = (TextView) mTextViewField.get(tabView);
                        tabView.setPadding(0, 0, 0, 0);
                        //因为我想要的效果是  字多宽线就多宽，所以测量mTextView的宽度
                        int tabWidth = 0;
                        tabWidth = tabView.getWidth();
                        if (tabWidth == 0) {
                            tabView.measure(0, 0);
                            tabWidth = mTextView.getMeasuredWidth();
                        }
                        LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) tabView.getLayoutParams();
                        int margin = (tabWidth - mTextView.getWidth()) / 2;
                        params.leftMargin = margin;
                        params.rightMargin = margin;
                        tabView.setLayoutParams(params);
                        tabView.invalidate();
                    }
                } catch (NoSuchFieldException e) {
                    e.printStackTrace();
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                }
            }
        });
    }