Question

我试图从listview适配器的开头删除少量元素，当元素数量很大时，为了提高内存效率，我想保持相同的可见元素，但这不会因为删除而发生以下是相应的代码

listView.setOnScrollListener(new OnScrollListener() 
        {

        @Override
        public void onScroll(AbsListView view, int firstVisibleItem,
                int visibleItemCount, int totalItemCount) 
        {
            synchronized(loadLock)
            {
                if(totalItemCount>0)
                {

                    if(totalItemCount-firstVisibleItem-visibleItemCount<10 && offset!=highOffset &&load)
                    {
                        load=false;
                        offset=highOffset;
                        loadEvents();
                    }
                }
            }
        }
    });
}

public void loadEvents() 
{
        Response.Listener<JSONObject> response = new Response.Listener<JSONObject>() 
        {
            @Override
            public void onResponse(JSONObject response)
            {
                Log.d(TAG, response.toString());
                JSONArray events = null;
                try 
                {
                    events = response.getJSONArray("events");
                } 
                catch (JSONException e1) 
                {
                    e1.printStackTrace();
                }
                if (events != null)
                {
                    Event event;
                    for (int i = 0; i < events.length(); i++) 
                    {
                        //filling events list
                    }
                    highOffset+=events.length();
                    adapter.notifyDataSetChanged();
                    cleanListView();
                    load=true;
                }
            }
        };


        CustomRequest eventReq = new CustomRequest(Method.POST, URL, params,
                response, errorListener);
        AppController.getInstance().addToRequestQueue(eventReq);
    }

public void cleanListView()
    {
        if(eventsList.size()>=1000)
        {
        for(int i=0;i<100;i++)
        {
            eventsList.remove(0);
            adapter.notifyDataSetChanged();
        }
        lowOffset+=100;
    }
}

Answer 1

我建议使用RecyclerView而不是ListView，你将在android中自动优化内存性能。

Answer 2

我会尝试类似setSelectionFromTop的内容，如果我知道有多少项被删除等等

从开头删除项目后如何保持列表视图滚动位置

2 个答案: