我正在为我的应用程序内的Facebook编写一个照片选择器,我有一个带有网格布局的recyclerview,我想阻止向上滚动,我能够通过使用scrollToPosition
来做到这一点,这有效但不是我想要的方式
问题
当我点击第2行的照片时,该行跳到顶部并成为第1行可见行,如果我点击3行,则会发生同样的事情。
如果视图可见,我不希望再循环器移动它应保持不变,所以如果我点击最后一行可见的一张照片,我希望滚动保持不变,我不要#39; t希望它将最后一行作为第一行。
试图解决它
我尝试了几件事来解决这个问题,我尝试拨打setNestedScrollingEnabled
我跟着这个How to disable RecyclerView scrolling?
public static void onItemClick(int position){
//picker.setNestedScrollingEnabled(false);
for(int k = 0; k<photoBag.size();k++) {
if(k == position)
photoBag.set(position, new PhotoBag(photoBag.get(position).getPhoto(), true)); //Here im marking the photo to selected
else
photoBag.set(k, new PhotoBag(photoBag.get(k).getPhoto(), false));//Here im setting unselecting all the other photos
}
picker.setAdapter(adapter);
adapter.notifyDataSetChanged();
picker.scrollToPosition(position);
//Log.d("FacebookPicker", "position " + grid.findFirstCompletelyVisibleItemPosition());
//picker.setNestedScrollingEnabled(true);
}
我认为可能禁用滚动条会将Recyclerview锁定在正确的位置,但它没有向右跳跃。
我也试过获取Vertical偏移并在调用notifyDataSetChange后设置它,但我找不到以编程方式设置偏移量的方法
修改
适配器
class PickerAdapter extends RecyclerView.Adapter<PickerAdapter.PickerAdapterHolder> {
public final String TAG = "PickerAdapter";
private ArrayList<PhotoBag> photoBag;
private Context context;
private OnClickListener onClickListener;
class PickerAdapterHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
ImageView photo;
ImageView imageBorder;
PickerAdapterHolder(View view) {
super(view);
photo = (ImageView) view.findViewById(R.id.photoItem);
photo.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.photoItem:
FacebookPhotoPicker.onItemClick(getAdapterPosition()); //i know that there are better ways to get the clicked item from other class but since im still debuging i don't need to worry about performace i just need it to work
break;
}
}
}
PickerAdapter(Context context, ArrayList<PhotoBag> itemList) {
this.photoBag = itemList;
this.context = context;
}
@Override
public PickerAdapterHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.facebook_picker_item, null);
return new PickerAdapterHolder(layoutView);
}
@Override
public void onBindViewHolder(final PickerAdapterHolder holder, final int position) {
if(photoBag.get(position).isSelected()){
int border = Math.round(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 5, context.getResources().getDisplayMetrics()));
Bitmap photo = photoBag.get(position).getPhoto();
photo = Bitmap.createScaledBitmap(photo,photo.getWidth() - (border*2), photo.getHeight() - (border*2), false);
photo = addWhiteBorder(photo,border);
holder.photo.setImageBitmap(photo);
}else {
holder.photo.setImageBitmap(photoBag.get(position).getPhoto());
}
}
@Override
public int getItemCount() {
return this.photoBag.size();
}
private Bitmap addWhiteBorder(Bitmap bmp, int borderSize) {
Bitmap bmpWithBorder = Bitmap.createBitmap(bmp.getWidth() + borderSize * 2, bmp.getHeight() + borderSize * 2, bmp.getConfig());
Canvas canvas = new Canvas(bmpWithBorder);
canvas.drawColor(Color.WHITE);
canvas.drawBitmap(bmp, borderSize, borderSize, null);
return bmpWithBorder;
}
答案 0 :(得分:1)
从$IDs = trim($_POST['IDs']);
$IDs = explode("\n", $IDs);
$IDs = array_map('trim', $IDs);
$ID = array_unique($IDs,0);
print_r($ID);
onItemClick
每次picker.setAdapter(adapter);
picker.scrollToPosition(position);
它重置位置,现在您不需要再次设置新位置。
这应该有效。如果没有,请查看我的答案(及其评论),提供ID How to remain at a scroll position in RecyclerView after adding items at its first index and call notifydatasetchange