使用自定义适配器将数据添加到 Listview 运行时

Question

PROBLEM : when i am click on add button then all data are clear and only one item is shows.... i want to Show Old items as well as new added item...

this is my code.....

MODEL class

public class GroupModel {
    ArrayList<String> G_member=new ArrayList<String>();
    ArrayList<String> G_name = new ArrayList<String>();


    public ArrayList<String> getG_member() {
        return G_member;
    }

    public void setG_member(ArrayList<String> g_member) {
        G_member = g_member;
    }
    public void addToGmember(String gname){
        this.G_member.add(gname);
    }

    public ArrayList<String> getG_name() {
        return G_name;
    }

    public void setG_name(ArrayList<String> g_name) {
        G_name = g_name;
    }
    public void addToGname(String name){
        this.G_name.add(name);
    }
}

MAIN ACTIVITY

public class MainActivity extends ActionBarActivity {

    Context context=this;
    private ListView lv;
    ImageView plus_img;// plus button to add GROUP Runtime.
    GroupModel model = new GroupModel();
    GroupAdapter adapter;
    ListView myListView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        lv = (ListView) findViewById(R.id.group__listview);
        myListView = lv;
        //plus image
        plus_img = (ImageView) findViewById(R.id.add_img);
        plus_img.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                model.addToGname("jignesh");
                model.addToGmember("8");
                ArrayList<GroupModel> l = new ArrayList<GroupModel>();
                l.add(model);
           //     adapter.setListData(getListData());
                myListView.setAdapter(new GroupAdapter(context, l));
            //    adapter.notifyDataSetChanged();
            }
        });


        adapter= new GroupAdapter(context,getListData());
        lv.setAdapter(adapter);

}

    private ArrayList getListData() {
        ArrayList list = new ArrayList();
        int untilloop;

        if(model.getG_member().size()>10)
        {
            untilloop = model.getG_member().size();
            for (int i=0;i<untilloop;i++)
            {
                model.getG_member();
                model.getG_name();
                list.add(model);
            }
        }
        else{
            untilloop=10;
            for(int i = 0; i <untilloop; i++){
                model.getG_name().add("raj "+i );
                model.getG_member().add(""+i);
                list.add(model);
            }
        }

        return list;
    }
}

ADAPTER class

public class GroupAdapter extends BaseAdapter {
    ArrayList<GroupModel> glist;
    Context context;
    private LayoutInflater layoutInflater;

    public GroupAdapter(Context mainActivity, ArrayList<GroupModel> glist) {
        context = mainActivity;
        this.glist=glist;
        layoutInflater = LayoutInflater.from(context);
    }
    public void setListData(ArrayList<GroupModel> data){
        glist = data;
    }

    @Override
    public int getCount() {
        return glist.size();
    }

    @Override
    public Object getItem(int position) {
        return glist.get(position);
    }

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if(convertView==null){
         //  LayoutInflater inflater = ((Activity) context).getLayoutInflater();
            convertView = layoutInflater.inflate(R.layout.row_list_data,null);
            holder= new ViewHolder();
            holder.g_number=(TextView)convertView.findViewById(R.id.txt_g_number);
            holder.g_name=(TextView)convertView.findViewById(R.id.txt_g_name);
            holder.nxt_aerrow=(ImageView)convertView.findViewById(R.id.img_nxt);
            convertView.setTag(holder);
        }else {
            holder = (ViewHolder) convertView.getTag();
        }
        holder.g_number.setText(glist.get(position).getG_member().get(position).toString());
        holder.g_name.setText(glist.get(position).getG_name().get(position).toString());

        holder.nxt_aerrow.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context,"image click",Toast.LENGTH_SHORT).show();
            }
        });
        return convertView;
    }
    static class ViewHolder {
        TextView g_number,g_name;
        ImageView nxt_aerrow;
    }
}

Answer 1

try this add the method in Adapter:

public void addItem(GroupModel groupModel){
   yourList.add(groupModel);
  notifyDataSetChanged();
}

And On Click method do this,

plus_img.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                model.addToGname("jignesh");
                model.addToGmember("8");

                adapter.addItem(model);
            }
        });

Answer 2

You always got one element in your ListView because every time you click on add button , you create new ArrayList then you add one element to your ArrayList => your ArrayList always have one item => your ListView always have one item

So Simply move ArrayList<GroupModel> l = new ArrayList<GroupModel>(); to outside of plus_img.setOnClickListener(new View.OnClickListener()

...
ArrayList<GroupModel> l = new ArrayList<GroupModel>();
...
plus_img.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               ...
            }
});

Answer 3

Try below code in you activity.

public class MainActivity extends ActionBarActivity {

Context context=this;
private ListView lv;
ImageView plus_img;// plus button to add GROUP Runtime.
GroupModel model = new GroupModel();
GroupAdapter adapter;
ListView myListView;
ArrayList<GroupModel> l = new ArrayList<GroupModel>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    lv = (ListView) findViewById(R.id.group__listview);
    myListView = lv;
    //plus image
    plus_img = (ImageView) findViewById(R.id.add_img);
    plus_img.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            model.addToGname("jignesh");
            model.addToGmember("8");
            l.add(model);
       //     adapter.setListData(getListData());
            myListView.setAdapter(new GroupAdapter(context, l));
        //    adapter.notifyDataSetChanged();
        }
    });


    adapter= new GroupAdapter(context,getListData());
    lv.setAdapter(adapter);

}

private ArrayList getListData() {
    ArrayList list = new ArrayList();
    int untilloop;

    if(model.getG_member().size()>10)
    {
        untilloop = model.getG_member().size();
        for (int i=0;i<untilloop;i++)
        {
            model.getG_member();
            model.getG_name();
            list.add(model);
        }
    }
    else{
        untilloop=10;
        for(int i = 0; i <untilloop; i++){
            model.getG_name().add("raj "+i );
            model.getG_member().add(""+i);
            list.add(model);
        }
    }

    return list;
}
}

Answer 4

adapter= new GroupAdapter(context,getListData()); lv.setAdapter(adapter);

if u observe this line you are setting whatever getListData() is returning...so declare a new Global List and later do the following

globalList.addAll(getListData());
adapter= new GroupAdapter(context,globalList);

Now you can preserve both old as well as new data...you maintain a new list where in you have all the data....and manipulate using that "globalList"

Thank you