我有一个RecyclerView
和Cardview
个。我希望在此CardView中滑动图像,就像在OLX应用程序中一样。最好的方法是什么?我考虑将viewpager放在cardview中。可以,或者我应该尝试其他方法吗?
我用ViewPager
做到了,但是看起来太慢了。这是viewpager适配器的一部分。
@Override
public Object instantiateItem(ViewGroup collection, int position) {
LayoutInflater inflater = LayoutInflater.from(mContext);
ViewGroup layout = (ViewGroup) inflater.inflate(R.layout.viewpager_custom, collection, false);
collection.addView(layout);
ImageView image = (ImageView) layout.findViewById(R.id.viewPagerImageView);
image.setImageResource(mPics[position]);
return layout;
}
您的方法正确。
只需加载压缩位图而不是未压缩位图就可以。您直接将位图资源设置为您的imageview。请使用Picasso之类的库https://github.com/square/picasso/
或使用Google的官方资源有效加载大型位图。
首先在您的活动中复制此方法:
public static int calculateInSampleSize(
BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int halfHeight = height / 2;
final int halfWidth = width / 2;
// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) > reqHeight
&& (halfWidth / inSampleSize) > reqWidth) {
inSampleSize *= 2;
}
}
return inSampleSize;
}
然后使用此方法解码位图:
public static Bitmap decodeSampledBitmapFromResource(Resources res, int resId,
int reqWidth, int reqHeight) {
// First decode with inJustDecodeBounds=true to check dimensions
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeResource(res, resId, options);
// Calculate inSampleSize
options.inSampleSize = calculateInSampleSize(options, reqWidth, reqHeight);
// Decode bitmap with inSampleSize set
options.inJustDecodeBounds = false;
return BitmapFactory.decodeResource(res, resId, options);
}
然后像这样加载您的位图:
@Override
public Object instantiateItem(ViewGroup collection, int position) {
LayoutInflater inflater = LayoutInflater.from(mContext);
ViewGroup layout = (ViewGroup) inflater.inflate(R.layout.viewpager_custom, collection, false);
collection.addView(layout);
ImageView image = (ImageView) layout.findViewById(R.id.viewPagerImageView);
image.setImageBitmap(
decodeSampledBitmapFromResource(getResources(), R.id.myimage, reqwidth, reqheight));
return layout;
}
我将在GitHub上使用以下库来实现此更改。完成后,它可以让您进行热刷和从ListView
中删除项目。
使用下面的示例为您提供帮助:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mItems = new ArrayList<>(30);
for (int i = 0; i < 30; i++) {
mItems.add(String.format("Card number %2d", i));
}
mAdapter = new CardViewAdapter(mItems);
mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mRecyclerView.setAdapter(mAdapter);
SwipeableRecyclerViewTouchListener swipeTouchListener =
new SwipeableRecyclerViewTouchListener(mRecyclerView,
new SwipeableRecyclerViewTouchListener.SwipeListener() {
@Override
public boolean canSwipe(int position) {
return true;
}
@Override
public void onDismissedBySwipeLeft(RecyclerView recyclerView, int[] reverseSortedPositions) {
for (int position : reverseSortedPositions) {
mItems.remove(position);
mAdapter.notifyItemRemoved(position);
}
mAdapter.notifyDataSetChanged();
}
@Override
public void onDismissedBySwipeRight(RecyclerView recyclerView, int[] reverseSortedPositions) {
for (int position : reverseSortedPositions) {
mItems.remove(position);
mAdapter.notifyItemRemoved(position);
}
mAdapter.notifyDataSetChanged();
}
});
mRecyclerView.addOnItemTouchListener(swipeTouchListener);
希望这会有所帮助:)