java - 在自定义日历中实现 ViewPager

Question

我有一个带有 2 个选项卡的 FragmentActivity。每个选项卡调用一个 fragment - 日历和转换器:

public class Calendar extends SherlockFragmentActivity {

//create tabs
}


private class MyTabListener implements ActionBar.TabListener
{
    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        if(tab.getPosition()==0)
        {
            CalendarFragment frag = new CalendarFragment();
            ft.replace(android.R.id.content, frag);
        }
        else
        {
            ConverterFragment frag = new ConverterFragment();
            ft.replace(android.R.id.content, frag);
        }
    }
..

}

在Calendar fragment ，我想为月 View 实现 ViewPager，以便用户在更改月份时可以滑动下一个/上一个。

这是我到目前为止的代码。但这所做的只是显示当前月份的日历。

public class CalendarFragment extends Fragment implements OnClickListener {

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
       View v =  inflater.inflate(R.layout.simple_calendar_view, container, false);

       //set calendar adapter 
       //Code from http://w2davids.wordpress.com/android-simple-calendar/

       context = this.getActivity().getApplicationContext();
       CalendarPagerAdapter adapter = new CalendarPagerAdapter();
       myPager = (ViewPager) v.findViewById(R.id.pager);
       myPager.setAdapter(adapter);
       myPager.setCurrentItem(1);
    }


   public class CalendarPagerAdapter extends PagerAdapter {

         public int getCount() {
                 return NUM_AWESOME_VIEWS;
         }

         public Object instantiateItem(View collection, int position) {
                 Log.d("Object", "Instantiated");
                LayoutInflater inflater = (LayoutInflater) collection.getContext()
                                 .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

                View v =  inflater.inflate(R.layout.simple_calendar_view, null);

                _calendar = Calendar.getInstance(Locale.getDefault());
                month = _calendar.get(Calendar.MONTH) + 1;
                year = _calendar.get(Calendar.YEAR);

                calendarView = (GridView) v.findViewById(R.id.calendar);
                calendarWeek = (GridView) v.findViewById(R.id.calendarweek);

                calendarWeek.setAdapter(new CalendarWeekAdapter(context));
                // Initialised
                adapter = new GridCellAdapter(context, R.id.calendar_day_gridcell, month, year);
                adapter.notifyDataSetChanged();
                calendarView.setAdapter(adapter);

                ((ViewPager) collection).addView(v, 0);

                return v;
         }

         @Override
         public void destroyItem(View arg0, int arg1, Object arg2) {
                 ((ViewPager) arg0).removeView((View) arg2);

         }

         @Override
         public void finishUpdate(View arg0) {
                 // TODO Auto-generated method stub

         }

         @Override
         public boolean isViewFromObject(View arg0, Object arg1) {
                 return arg0 == ((View) arg1);

         }

         @Override
         public void restoreState(Parcelable arg0, ClassLoader arg1) {
                 // TODO Auto-generated method stub

         }

         @Override
         public Parcelable saveState() {
                 // TODO Auto-generated method stub
                 return null;
         }

         @Override
         public void startUpdate(View arg0) {
                 // TODO Auto-generated method stub

         }

     }

}

我被困在这里，因为我不知道如何在用户向左滑动时显示上个月的日历，以及在用户向右滑动时显示下个月的日历。

我尝试将此代码添加到 Object instantiateItem:

 switch(position){
    case 0:
       Log.d("ViewPager", "Prev");
       if (month <= 1)
            {
                month = 12;
                year--;
            }
        else
            {
                month--;
            }
        if (hmonth <= 1)
            {
                hmonth = 12;
                hyear--;
            }
        else
            {
                hmonth--;
            }
        setGridCellAdapterToDate(month, year);
    break;
    case 2:

       Log.d("ViewPager", "Next");
       if (month > 11)
            {
                month = 1;
                year++;
            }
        else
            {
                month++;
            }
        if (hmonth > 11)
            {
                hmonth = 1;
                hyear++;
            }
        else
            {
                hmonth++;
            }
        setGridCellAdapterToDate(month, year);

    break;
    }

但是没有滑动发生。我哪里错了？

Answer 1

有时触摸事件监听器不能很好地协同工作。为 CalendarFragment 实现 onClickListenr 可能会从您的 PagerAdapter 窃取触摸事件。

-------- 编辑--------

If Log.d("对象", "实例化");每次滑动时都会显示在您的调试日志中，您的 PagerAdapter 正在工作。这意味着您如何更改要显示的当前月份存在问题。

试试这个:

// put this at the class level of calendarFragment.
Calendar holdTodaysDate = Calendar.getInstance(Locale.getDefault());


_calendar = Calendar.getInstance(Locale.getDefault());
_calendar = holdTodaysDate; // Add this line;
_calendar.add(Calendar.MONTH, position); // Add this line
month = _calendar.get(Calendar.MONTH) + 1;
year = _calendar.get(Calendar.YEAR);

这是在添加位置之前将日历重置为今天的日期。现在 _calendar 的方式是在 View 之间保持它的状态。