how to insert the data from the adapter to the listview

问题

In my activity I have one adapter contains 25 items , and I have one listview. I want to insert 5 items in the listview and if I press the next button in my ativity ,the page will reloads with the next 5 items and so on.

回答1:

Alter the items in the adapter, and then call notifyDataSetChanged() on the adapter.

adapter.clear();
adapter.addAll(nextFiveElements);
adapter.notifyDataSetChanged();

Also, be scrupulous about using the ViewHolder pattern. When implementing getView(), utilizing this design pattern will save a LOT of memory:

http://www.screaming-penguin.com/node/7767

回答2:

you should not add all 25 items to the adapter unnecessarily. add five values only ;

    static int pageNo. = 0 ;
    final int pageSize = 5;
    btn.onClick()
    {
    pageNo.+=;
    for(int i = pageNo. ;i<pageN0. + pageSize;i++)
    {
    adapter.add(*i'th value*);
    //modify syntext as per need 
    }

回答3:

You have to maintain the position of the array

I have created a demo Adapter you can see

private static final int NO_OF_ITEMS_IN_PAGE = 5;
pivate static int currentPageNo = 0;

public class MyAdapter extends BaseAdapter {

    ArrayList<String> arrNotes;
    LayoutInflater inflater;
    public MyAdapter(Context c, ArrayList<String> arrNotes) {
        this.arrNotes = arrNotes;
        inflater = ((Activity) c).getLayoutInflater();
    }

    @Override
    public int getCount() {
        return NO_OF_ITEMS_IN_PAGE;
    }

    @Override
    public Object getItem(int position) {
        int actualPosition = currentPageNo * NO_OF_ITEMS_IN_PAGE + position;
        return arrTodaysMedicines.get(actualPosition);
    }

    @Override
    public long getItemId(int arg0) {
        return arg0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup arg2) {
        int actualPosition = currentPageNo * NO_OF_ITEMS_IN_PAGE + position;
        String strNote = arrNotes.get(actualPosition);
        if(convertView == null) {
            convertView = inflater.inflate(R.layout.note_list, null);
        }
        TextView tvTitle = 
             (TextView) convertView.findViewById(R.id.tvTitle);

        tvTitle.setText(strNote);
        return convertView;
    }

}

来源：https://stackoverflow.com/questions/8166092/how-to-insert-the-data-from-the-adapter-to-the-listview

标签

android

adapter