android.widget.ListView#setDrawingCacheEnabled ( )源码实例Demo

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
	
	initTitle();

	View v = inflater.inflate(R.layout.home_timeline, null);
	mList = (ListView) v.findViewById(R.id.home_timeline);
	mCache = bindApiCache();
	mCache.loadFromCache();
	mAdapter = new WeiboAdapter(getActivity(), mList, mCache.mMessages, mBindOrig, mShowCommentStatus);
	mList.setAdapter(mAdapter);
	
	mList.setDrawingCacheEnabled(true);
	mList.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_HIGH);
	mList.setPersistentDrawingCache(ViewGroup.PERSISTENT_ANIMATION_CACHE | ViewGroup.PERSISTENT_SCROLLING_CACHE);
	
	// Swipe To Refresh
	bindSwipeToRefresh((ViewGroup) v);
	
	if (mCache.mMessages.getSize() == 0) {
		new Refresher().execute(new Boolean[]{true});
	}
	
	// Floating "New" button
	bindNewButton(v);
	
	return v;
}
 

@SuppressWarnings("unchecked")
@Override
public View createView(Context context) {
    actionBar.setBackgroundColor(Theme.ACTION_BAR_MEDIA_PICKER_COLOR);
    actionBar.setItemsBackgroundColor(Theme.ACTION_BAR_PICKER_SELECTOR_COLOR);
    // actionBar.setBackButtonImage(R.drawable.ic_ab_back);
    actionBar.setBackText(context.getString(R.string.Cancel));
    actionBar.setActionBarMenuOnItemClick(new ActionBar.ActionBarMenuOnItemClick() {
        @Override
        public void onItemClick(int id) {
            if (id == -1) {
                finishFragment();
            } else if (id == 1) {
                if (delegate != null) {
                    finishFragment(false);
                    delegate.startPhotoSelectActivity();
                }
            } else if (id == item_photos) {
                refreshShowPic();//刷新照片目录
            } else if (id == item_video) {
                refreshShowVedio();//刷新录像目录
            }
        }
    });


    fragmentView = new FrameLayout(context);

    FrameLayout frameLayout = (FrameLayout) fragmentView;
    frameLayout.setBackgroundColor(DarkTheme ? 0xff000000 : 0xffffffff);
    //==============videos pick====================
    int res = !singlePhoto && filterMimeTypes.length > 0 ? R.string.PickerVideo : R.string.Album;
    actionBar.setTitle(context.getString(res));
    selectedMode = filterMimeTypes.length > 0 ? 1 : selectedMode;
    listView = new ListView(context);
    listView.setPadding(AndroidUtilities.dp(4), 0, AndroidUtilities.dp(4),
            AndroidUtilities.dp(4));
    listView.setClipToPadding(false);
    listView.setHorizontalScrollBarEnabled(false);
    listView.setVerticalScrollBarEnabled(false);
    listView.setSelector(new ColorDrawable(0));
    listView.setDividerHeight(0);
    listView.setDivider(null);
    listView.setDrawingCacheEnabled(false);
    listView.setScrollingCacheEnabled(false);
    frameLayout.addView(listView);
    FrameLayout.LayoutParams layoutParams = (FrameLayout.LayoutParams) listView
            .getLayoutParams();
    layoutParams.width = LayoutHelper.MATCH_PARENT;
    layoutParams.height = LayoutHelper.MATCH_PARENT;
    // layoutParams.bottomMargin = AndroidUtilities.dp(48);
    listView.setLayoutParams(layoutParams);
    listView.setAdapter(listAdapter = new ListAdapter(context));
    AndroidUtilities.setListViewEdgeEffectColor(listView, 0xff333333);

    emptyView = new TextView(context);
    emptyView.setTextColor(0xff808080);
    emptyView.setTextSize(20);
    emptyView.setGravity(Gravity.CENTER);
    emptyView.setVisibility(View.GONE);
    emptyView.setText(R.string.NoPhotos);
    frameLayout.addView(emptyView);
    layoutParams = (FrameLayout.LayoutParams) emptyView.getLayoutParams();
    layoutParams.width = LayoutHelper.MATCH_PARENT;
    layoutParams.height = LayoutHelper.MATCH_PARENT;
    layoutParams.bottomMargin = AndroidUtilities.dp(48);
    emptyView.setLayoutParams(layoutParams);
    emptyView.setOnTouchListener(new View.OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            return true;
        }
    });

    progressView = new FrameLayout(context);
    progressView.setVisibility(View.GONE);
    frameLayout.addView(progressView);
    layoutParams = (FrameLayout.LayoutParams) progressView.getLayoutParams();
    layoutParams.width = LayoutHelper.MATCH_PARENT;
    layoutParams.height = LayoutHelper.MATCH_PARENT;
    layoutParams.bottomMargin = AndroidUtilities.dp(48);
    progressView.setLayoutParams(layoutParams);

    ProgressBar progressBar = new ProgressBar(context);
    progressView.addView(progressBar);
    layoutParams = (FrameLayout.LayoutParams) progressView.getLayoutParams();
    layoutParams.width = LayoutHelper.WRAP_CONTENT;
    layoutParams.height = LayoutHelper.WRAP_CONTENT;
    layoutParams.gravity = Gravity.CENTER;
    progressView.setLayoutParams(layoutParams);


    if (loading && (albumsSorted == null || albumsSorted != null && albumsSorted.isEmpty())) {
        progressView.setVisibility(View.VISIBLE);
        listView.setEmptyView(null);
    } else {
        progressView.setVisibility(View.GONE);
        listView.setEmptyView(emptyView);
    }
    return fragmentView;
}
 

@Override
   public void onCreate(Bundle savedInstanceState)
{
	//supportRequestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
       super.onCreate(savedInstanceState);

	setContentView(R.layout.fm);
	fListView = (ListView) findViewById(R.id.list);

	path = savedInstanceState != null ? savedInstanceState.getString(CURR_DIR) : FILE_SEPARATOR;//Environment.getExternalStorageDirectory().toString();

       fListView.setDrawingCacheEnabled(true);
	fAdapter = new FMAdapter(this, R.layout.fm_row);

	fListView.setAdapter(fAdapter);

	ls(path, false);

	getSupportActionBar().setSubtitle(path);
	fListView.setOnItemClickListener(new AdapterView.OnItemClickListener()
	{
			@Override
			public void onItemClick(AdapterView<?> arg0, View arg1, int pos,
									long arg3)
			{
                   FMEntry entry = fAdapter.getItem(pos);
                   if(entry.getType() == TYPE_DIRECTORY || entry.getType() == TYPE_DIRECTORY_LINK)
                   {
                       Parcelable state = fListView.onSaveInstanceState();
                       listScrollStates.put(path, state);
                       backstack.add(path);
                       path = entry.getType() == TYPE_DIRECTORY_LINK ? entry.getLink() : entry.getPath();
                       validatePath();
                       ls(path, false);
                   }
                   else if(entry.getType() == TYPE_FILE || entry.getType() == TYPE_LINK)
                   {
                       //TODO
                   }
			}
		});
	if(savedInstanceState != null)
	{
           backstack = (LinkedList<String>) savedInstanceState.getSerializable(BACKSTACK);
		Parcelable listState = savedInstanceState.getParcelable("list_position");
		if(listState != null)fListView.post(new RestoreListStateRunnable(listState));
	}
   }