私は通常約 110 ページを格納する ViewPager を持っています。各ページは SQLite データベースからのデータで満たされ、多くの TextView といくつかの ImageView があります。しかし、このような大量のビューは大量のメモリを消費するため、java.lang.OutOFMemoryError: ビットマップ サイズが VM の予算を超えています. だから私はこれを2つの方法で表示しようとしました-最初は3ページだけを使用して、ユーザーがページを中央のページから右のページにスワイプしたときにリッスンしようとしました。残念ながら、ページのスワイプはスムーズではなく、バグがありました。2回目の試行では、すべてのページを空白のビューで埋め、ユーザーの位置を聞き、位置、位置-1、および位置+1にデータで満たされたビューを追加しました。ページのスワイプは十分にスムーズでしたが、ユーザーが位置 2 (最初のページは任意) から ViewPager を実行し、位置 100 までスワイプすると、依然としてjava.lang.OutOFMemoryError: bitmap size exceeded VM Budget が発生します。
@Override
protected void onCreate(Bundle savedInstanceState)
{
for (int i=0; i < ids.length;i++)
{
viewsToShow[i] = inflater.inflate(R.layout.blank, null);
if(ids[i] == getIntent().getIntExtra(DBC.IE_ID, -1))
currentIDPosition = i;
}
pagerAdapter = new MainPagerAdapter();
pager = (ViewPager) findViewById (R.id.pagerszcz);
pager.setAdapter (pagerAdapter);
for (int i = 0; i < viewsToShow.length; i++)
{
if(i == currentIDPosition-1)
{
viewsToShow[i] = (View) inflater.inflate(R.layout.szczegoly_item, null);
pobierzIZwiazDane(ids[i], viewsToShow[i]); // pobierzIZwiazDane fills view by data from SQLite database and images
pagerAdapter.addView (viewsToShow[i], i);
}
else if (i == currentIDPosition)
{
viewsToShow[currentIDPosition] = (View) inflater.inflate(R.layout.szczegoly_item, null);
pobierzIZwiazDane(ids[currentIDPosition], viewsToShow[currentIDPosition]);
pagerAdapter.addView (viewsToShow[i], i);
}
else if (i == currentIDPosition+1)
{
viewsToShow[i] = (View) inflater.inflate(R.layout.szczegoly_item, null);
pobierzIZwiazDane(ids[i], viewsToShow[i]);
pagerAdapter.addView (viewsToShow[i], i);
}
else
pagerAdapter.addView (viewsToShow[i], i);
}
pagerAdapter.notifyDataSetChanged();
pager.setCurrentItem(currentIDPosition);
pager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
/* int oldPage=1;
int newPage;*/
public void onPageSelected(int position) {
mSelectedPageIndex = position;
//Log.d("mselect",position+" "+ pager.getCurrentItem());
}
public void onPageScrolled(int arg0, float arg1, int arg2) {
// Swipe to right page
if (pager.getCurrentItem()<currentIDPosition && pager.getCurrentItem() > 0)
{
Log.d("Zmniejszenie", pager.getCurrentItem()+" "+currentIDPosition);
currentIDPosition--;
pagerAdapter.removeView(pager, currentIDPosition-1);
viewsToShow[currentIDPosition-1] = (View) inflater.inflate(R.layout.szczegoly_item, null);
pobierzIZwiazDane(ids[currentIDPosition-1], viewsToShow[currentIDPosition-1]);
pagerAdapter.addView (viewsToShow[currentIDPosition-1], currentIDPosition-1);
new Handler().post(new Runnable() {
public void run() { // Removing view at current postion +2
viewsToShow[currentIDPosition+2] = null;
viewsToShow[currentIDPosition+2] = new View(SzczegolyViewPagerActivity.this);
pagerAdapter.removeView(pager, currentIDPosition+2);
pagerAdapter.addView (viewsToShow[currentIDPosition+2], currentIDPosition+2);
}
});
pagerAdapter.notifyDataSetChanged();
}
else if (pager.getCurrentItem()>currentIDPosition && pager.getCurrentItem() < ids.length-1)
{// Swipe to left page
Log.d("Zwiekszenie", pager.getCurrentItem()+" "+currentIDPosition);
currentIDPosition++;
pagerAdapter.removeView(pager, currentIDPosition+1);
viewsToShow[currentIDPosition+1] = (View) inflater.inflate(R.layout.szczegoly_item, null);
pobierzIZwiazDane(ids[currentIDPosition+1], viewsToShow[currentIDPosition+1]);
pagerAdapter.addView (viewsToShow[currentIDPosition+1], currentIDPosition+1);
new Handler().post(new Runnable() {
public void run() {
viewsToShow[currentIDPosition-2] = new View(SzczegolyViewPagerActivity.this);
pagerAdapter.removeView(pager, currentIDPosition-2);
pagerAdapter.addView (viewsToShow[currentIDPosition-2], currentIDPosition-2);
}
});
pagerAdapter.notifyDataSetChanged();
}
}
public void onPageScrollStateChanged(int state) {
if (state == ViewPager.SCROLL_STATE_IDLE) {
Log.d("pagec", currentIDPosition+" "+pager.getCurrentItem() + " " +pagerAdapter.getCount() + " " + mSelectedPageIndex);
}
}
});
}
class MainPagerAdapter extends PagerAdapter
{
// This holds all the currently displayable views, in order from left to right.
private ArrayList<View> views = new ArrayList<View>();
private LayoutInflater inflater;
public MainPagerAdapter()
{
inflater = getLayoutInflater();
}
//-----------------------------------------------------------------------------
// Used by ViewPager. "Object" represents the page; tell the ViewPager where the
// page should be displayed, from left-to-right. If the page no longer exists,
// return POSITION_NONE.
@Override
public int getItemPosition (Object object)
{
int index = views.indexOf (object);
if (index == -1)
return POSITION_NONE;
else
return index;
}
//-----------------------------------------------------------------------------
// Used by ViewPager. Called when ViewPager needs a page to display; it is our job
// to add the page to the container, which is normally the ViewPager itself. Since
// all our pages are persistent, we simply retrieve it from our "views" ArrayList.
@Override
public Object instantiateItem (ViewGroup container, int position)
{
View v = views.get (position);
//View cont = inflater.inflate(R.layout.szczegoly_item, container, false);
container.addView (v);
return v;
}
//-----------------------------------------------------------------------------
// Used by ViewPager. Called when ViewPager no longer needs a page to display; it
// is our job to remove the page from the container, which is normally the
// ViewPager itself. Since all our pages are persistent, we do nothing to the
// contents of our "views" ArrayList.
@Override
public void destroyItem (ViewGroup container, int position, Object object)
{
container.removeView (views.get (position));
}
//-----------------------------------------------------------------------------
// Used by ViewPager; can be used by app as well.
// Returns the total number of pages that the ViewPage can display. This must
// never be 0.
@Override
public int getCount ()
{
return views.size();
}
//-----------------------------------------------------------------------------
// Used by ViewPager.
@Override
public boolean isViewFromObject (View view, Object object)
{
return view == object;
}
//-----------------------------------------------------------------------------
// Add "view" to right end of "views".
// Returns the position of the new view.
// The app should call this to add pages; not used by ViewPager.
public int addView (View v)
{
return addView (v, views.size());
}
//-----------------------------------------------------------------------------
// Add "view" at "position" to "views".
// Returns position of new view.
// The app should call this to add pages; not used by ViewPager.
public int addView (View v, int position)
{
views.add (position, v);
return position;
}
//-----------------------------------------------------------------------------
// Removes "view" from "views".
// Retuns position of removed view.
// The app should call this to remove pages; not used by ViewPager.
public int removeView (ViewPager pager, View v)
{
return removeView (pager, views.indexOf (v));
}
//-----------------------------------------------------------------------------
// Removes the "view" at "position" from "views".
// Retuns position of removed view.
// The app should call this to remove pages; not used by ViewPager.
public int removeView (ViewPager pager, int position)
{
// ViewPager doesn't have a delete method; the closest is to set the adapter
// again. When doing so, it deletes all its views. Then we can delete the view
// from from the adapter and finally set the adapter to the pager again. Note
// that we set the adapter to null before removing the view from "views" - that's
// because while ViewPager deletes all its views, it will call destroyItem which
// will in turn cause a null pointer ref.
// pager.setAdapter (null);
views.remove (position);
// pager.setAdapter (this);
return position;
}
//-----------------------------------------------------------------------------
// Returns the "view" at "position".
// The app should call this to retrieve a view; not used by ViewPager.
public View getView (int position)
{
return views.get (position);
}
// Other relevant methods:
// finishUpdate - called by the ViewPager - we don't care about what pages the
// pager is displaying so we don't use this method.
}
pobierzIZwiazDane(database record id, view) は、データベースからのデータでページを埋める責任があります。