The bottom line is this. I created a custom layout.

public class CustomAdapterView extends LinearLayout { private int postiton; private View mGlobalView; ArrayList<SquareLayout> containerIds = new ArrayList<>(); ArrayList<LinearLayout> rows = new ArrayList<>(); private BaseAdapter adapter; private ImageView mFindButton = new ImageButton(getContext()); private final DataSetObserver observer = new DataSetObserver() { @Override public void onChanged() { refreshViewsInAdapter(); } @Override public void onInvalidated() { removeAllViews(); } }; private void initContainers(){ containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_one)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_two)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_three)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_four)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_five)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_six)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_seven)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_eight)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_nine)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_ten)); containerIds.add((SquareLayout) mGlobalView.findViewById(R.id.container_eleven)); rows.add((LinearLayout) mGlobalView.findViewById(R.id.row_one)); rows.add((LinearLayout) mGlobalView.findViewById(R.id.row_two)); rows.add((LinearLayout) mGlobalView.findViewById(R.id.row_three)); } private void createInflater(){ LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); mGlobalView = inflater.inflate(R.layout.drag_and_drop_layout, this,true); initContainers(); } public CustomAdapterView(Context context) { super(context); createInflater(); } public CustomAdapterView(Context context, AttributeSet attrs) { super(context, attrs); createInflater(); } public CustomAdapterView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); createInflater(); } public BaseAdapter getAdapter() { return adapter; } public void setAdapter(BaseAdapter adapter) { if (this.adapter != null) { this.adapter.unregisterDataSetObserver(observer); } this.adapter = adapter; if (this.adapter != null) { this.adapter.registerDataSetObserver(observer); } initViewsFromAdapter(); } private void checkPosition(){ if(postiton >= 5) rows.get(1).setVisibility(View.VISIBLE); else rows.get(1).setVisibility(View.GONE); if(postiton >= 8) rows.get(2).setVisibility(View.VISIBLE); else rows.get(2).setVisibility(View.GONE); } //-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- private boolean enableFlagForFindButton = false; private void moveFindImage(){ if (postiton != containerIds.size() ) { if (enableFlagForFindButton) { if (mFindButton.getParent() != null) { ((SquareLayout) mFindButton.getParent()).removeView(mFindButton); containerIds.get(postiton).addView(mFindButton); } else { containerIds.get(postiton).addView(mFindButton); } } } } public void onEnableFindButton(boolean chose){ enableFlagForFindButton = chose; if (enableFlagForFindButton && postiton != containerIds.size()) { ViewGroup.LayoutParams layoutParams = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT); mFindButton.setLayoutParams(layoutParams); mFindButton.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { adapter.notifyDataSetChanged(); } }); containerIds.get(postiton).addView(mFindButton); } else { if(mFindButton.getParent() != null){ ((SquareLayout) mFindButton.getParent()).removeView(mFindButton); } } } public void setImageForFindButton(int res){ mFindButton.setImageResource(res); } public void setOnClickForButtonFind(OnClickListener onClick){ mFindButton.setOnClickListener(onClick); } //-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- protected void initViewsFromAdapter() { if (adapter != null) { int adapterSize = adapter.getCount(); if (adapterSize > containerIds.size()){ adapterSize = containerIds.size(); } postiton = adapterSize; checkPosition(); for (int i = 0; i < adapterSize; i++) { RelativeLayout rl = (RelativeLayout) adapter.getView(i, null, this); (containerIds.get(i)).addView(rl); } } } protected void refreshViewsInAdapter() { int adapterSize = adapter.getCount(); Log.i("ADAPTER_SIZE " ,""+ adapterSize); postiton = adapterSize; checkPosition(); for (int i = 0; i < adapterSize; i++) { containerIds.get(i).removeAllViewsInLayout(); } adapterSize = adapter.getCount(); for (int i = 0; i < adapterSize; i++) { containerIds.get(i).addView(adapter.getView(i,null,this)); } moveFindImage(); }

}

And I made an adapter for it, which will be inherited from BaseAdapter.

  public class MyDragNDropAdapter extends BaseAdapter { private ArrayList<Items> items = new ArrayList<>(); private Context context; private int itemLayout; public MyDragNDropAdapter(Context context, int itemLayout) { this.context = context; this.itemLayout = itemLayout; } @Override public int getCount() { return items.size(); } @Override public Object getItem(int position) { return items.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(final int position, View convertView, ViewGroup parent) { ViewHolder viewholder; if (convertView == null) { convertView = LayoutInflater.from(context).inflate(itemLayout, null); viewholder = new ViewHolder(convertView,position); convertView.setTag(viewholder); } else { viewholder = (ViewHolder)convertView.getTag(); } viewholder.image.setImageResource(items.get(position).image); viewholder.btn.setTag(position); viewholder.btn.setOnClickListener( new Button.OnClickListener() { @Override public void onClick(View v) { items.remove(position); ArrayList<Items> arr = items; items.clear(); for(int i = 0; i < arr.size();i++){ items.add(arr.get(i)); } notifyDataSetChanged(); } } ); return convertView; } public void addItem(Object object) { items.add((Items) object); } private static class ViewHolder{ View context; int position; ImageView image ; TextView text; Button btn; ViewHolder(View context,int position){ this.context = context; this.position = position; text = (TextView) context.findViewById(R.id.product_description); image = (ImageView) context.findViewById(R.id.product_image_in_item); btn = (Button) context.findViewById(R.id.close_button_in_item); } }

}

I want to make the removal of any item by button. But when the button is pressed, the elements from the ArrayList are deleted, but the screen is not updated.

The deletion method itself:

  viewholder.btn.setOnClickListener( new Button.OnClickListener() { @Override public void onClick(View v) { items.remove(position); ArrayList<Items> arr = items; items.clear(); for(int i = 0; i < arr.size();i++){ items.add(arr.get(i)); } notifyDataSetChanged(); } } );

The notifyDataSetChanged method for my custom Layout-a

  protected void refreshViewsInAdapter() { int adapterSize = adapter.getCount(); for (int i = 0; i < adapterSize; i++) { containerIds.get(i).removeAllViewsInLayout(); } adapterSize = adapter.getCount(); for (int i = 0; i < adapterSize; i++) { containerIds.get(i).addView(adapter.getView(i,null,this)); } }

    1 answer 1

    The solution turned out to be extremely simple. The number of elements decreased before the layout cleared. Because of this, the last element was not deleted.

     for (int i = 0; i <= adapterSize; i++) { containerIds.get(i).removeAllViewsInLayout(); removeDragListener(i); }

    added <= instead of <