如何使日历Viewpager像Android中的谷歌日历应用程序

Question

我想使日历像Google日历应用程序。我的意思是当用户滚动时它必须下个月调用，而向后滚动时它必须获得上个月。  因此，我在main_activity.xml中使用viewPager，并从main_activity.class中调用包含CalendarFragment.class的{​​{1}}。  但是，当我滚动recyclerView

时，我无法达到下个月或上个月

Here is the google calendar picture我只希望它可滚动。

MainActivity

viewPager

日历片段

public class MainActivity extends AppCompatActivity {
    ViewPager viewPager;
    SlideAdapter slideAdapter;
    HashSet<Date> events;
    List calendarFragmentList = new ArrayList();

    private Calendar currentDate = Calendar.getInstance();


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

        viewPager = (ViewPager)findViewById(R.id.view_pager);

        events = new HashSet<>();
        events.add(new Date());

        final CalendarFragment calendarFragment = new CalendarFragment();
        calendarFragmentList.add(calendarFragment);


        slideAdapter = new SlideAdapter(getSupportFragmentManager(), calendarFragmentList);
        viewPager.setAdapter(slideAdapter);

        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            private static final float thresholdOffset = 0.5f;
            private boolean scrollStarted, checkDirection;

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

                if (checkDirection) {
                    if (thresholdOffset > positionOffset) {

                        Log.i("onPageScrolled", "going left");


                        CalendarFragment calendarFragment = new CalendarFragment();

                        calendarFragment.currentDate.add(Calendar.MONTH, -1);

                        calendarFragment.updateCalendar();

                        calendarFragmentList.add(calendarFragment);

                        slideAdapter.notifyDataSetChanged();

                    } else {
                        Log.i("onPageScrolled", "going right");
                    }
                    checkDirection = false;
                }

            }

            @Override
            public void onPageSelected(int position) {

            }

            @Override
            public void onPageScrollStateChanged(int state) {

                if (!scrollStarted && state == ViewPager.SCROLL_STATE_DRAGGING) {
                    scrollStarted = true;
                    checkDirection = true;
                } else {
                    scrollStarted = false;
                }

            }
        });

    }

}