Android之Adapter用法总结

/**
     * @author 
     *
     */
    public class MyListView4 extends ListActivity {
     
     
        private List<Map<String, Object>> mData;
         
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            mData = getData();
            MyAdapter adapter = new MyAdapter(this);
            setListAdapter(adapter);
        }
     
        private List<Map<String, Object>> getData() {
            List<Map<String, Object>> list = new ArrayList<Map<String, Object>>();
     
            Map<String, Object> map = new HashMap<String, Object>();
            map.put("title", "G1");
            map.put("info", "google 1");
            map.put("img", R.drawable.i1);
            list.add(map);
     
            map = new HashMap<String, Object>();
            map.put("title", "G2");
            map.put("info", "google 2");
            map.put("img", R.drawable.i2);
            list.add(map);
     
            map = new HashMap<String, Object>();
            map.put("title", "G3");
            map.put("info", "google 3");
            map.put("img", R.drawable.i3);
            list.add(map);
             
            return list;
        }
         
        // ListView 中某项被选中后的逻辑
        @Override
        protected void onListItemClick(ListView l, View v, int position, long id) {
             
            Log.v("MyListView4-click", (String)mData.get(position).get("title"));
        }
         
        /**
         * listview中点击按键弹出对话框
         */
        public void showInfo(){
            new AlertDialog.Builder(this)
            .setTitle("我的listview")
            .setMessage("介绍...")
            .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                }
            })
            .show();
             
        }
         
         
         
        public final class ViewHolder{
            public ImageView img;
            public TextView title;
            public TextView info;
            public Button viewBtn;
        }
         
         
        public class MyAdapter extends BaseAdapter{
     
            private LayoutInflater mInflater;
             
             
            public MyAdapter(Context context){
                this.mInflater = LayoutInflater.from(context);
            }
            @Override
            public int getCount() {
                // TODO Auto-generated method stub
                return mData.size();
            }
     
            @Override
            public Object getItem(int arg0) {
                // TODO Auto-generated method stub
                return null;
            }
     
            @Override
            public long getItemId(int arg0) {
                // TODO Auto-generated method stub
                return 0;
            }
     
            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                 
                ViewHolder holder = null;
                if (convertView == null) {
                     
                    holder=new ViewHolder(); 
                     
                    convertView = mInflater.inflate(R.layout.vlist2, null);
                    holder.img = (ImageView)convertView.findViewById(R.id.img);
                    holder.title = (TextView)convertView.findViewById(R.id.title);
                    holder.info = (TextView)convertView.findViewById(R.id.info);
                    holder.viewBtn = (Button)convertView.findViewById(R.id.view_btn);
                    convertView.setTag(holder);
                     
                }else {
                     
                    holder = (ViewHolder)convertView.getTag();
                }
                 
                 
                holder.img.setBackgroundResource((Integer)mData.get(position).get("img"));
                holder.title.setText((String)mData.get(position).get("title"));
                holder.info.setText((String)mData.get(position).get("info"));
                 
                holder.viewBtn.setOnClickListener(new View.OnClickListener() {
                     
                    @Override
                    public void onClick(View v) {
                        showInfo();                
                    }
                });
                 
                 
                return convertView;
            }
             
        }     
    }