android开发之为listview绑定数据的三种方式

第一种，使用simple adapter

simpleadapter 是最简单的一种方式，但是其数据源必须是map类型。

1.生成 SimpleAdapter（）对象

2.设置数据源

3.设置每个item的布局

4.设置SimpleAdapter(Context context, //上下文

List<? extendsMap<String, ?>> data, //数据源

intresource, //每个item的布局

String[] from,//map的key

int[] to) //相应控件的id

5.为listview绑定SimpleAdapter

接下来看代码：

public class User {    private String userName;    private int userRank;    public User(String userName, int userRank) {        super();        this.userName = userName;        this.userRank = userRank;    }    public User(){        super();    }    public String getUserName() {        return userName;    }    public void setUserName(String userName) {        this.userName = userName;    }    public int getUserRank() {        return userRank;    }    public void setUserRank(int userRank) {        this.userRank = userRank;    }}

Actvity的代码：

public class RankingActivity extends Activity {    //数据源    ArrayList<User> al = new ArrayList<User>();    private ListView ls_rank;    List<Map<String, String>> data = new ArrayList<Map<String, String>>();    @Override    protected void onCreate(@Nullable Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.rankinglist);        ls_rank = (ListView) findViewById(R.id.ls_rank);        al.add(new User("aaa", 666));        al.add(new User("bbb", 777));        al.add(new User("ccc", 888));        fillData();//        第一种 simpleAdapter    SimpleAdapter adapter = new SimpleAdapter(RankingActivity.this,                data,                R.layout.rank_list_item,                new String[]{"userName", "userRank"},                new int[]{R.id.tv_name, R.id.tv_rank}); ls_rank.setAdapter(adapter); private void fillData() {        for (User user : al) {            Map<String, String> map = new HashMap<String, String>();            map.put("userName", user.getUserName());            map.put("userRank", user.getUserRank() + "");            data.add(map);        }    }

第二种：BaseAdapter

1.创建一个MyBaseAdapter，重写四个方法

 class MyBaseAdapter extends BaseAdapter {        @Override        public int getCount() {            return al.size();        }        @Override        public Object getItem(int i) {            return i;        }        @Override        public long getItemId(int i) {            return i;        }        @Override        public View getView(int i, View view, ViewGroup viewGroup) {            View row = view;            Wrapper wrapper;            if (row == null) {                row = getLayoutInflater().inflate(R.layout.rank_list_item, viewGroup, false);                wrapper = new Wrapper(row);                row.setTag(wrapper);            } else {                wrapper = (Wrapper) row.getTag();            }            TextView tvName = wrapper.gettvName();            TextView tvRank = wrapper.gettvRank();            tvName.setText(al.get(i).getUserName());            tvRank.setText(al.get(i).getUserRank()+"");            return row;        }    }    class Wrapper {        private TextView tvName;        private TextView tvRank;        private View row;        public Wrapper(View row) {            this.row = row;        }        public TextView gettvName() {            if (tvName == null) {                tvName = (TextView) row.findViewById(R.id.tv_name);            }            return tvName;        }        public TextView gettvRank() {            if (tvRank == null) {                tvRank = (TextView) row.findViewById(R.id.tv_rank);            }            return tvRank;        }    }

然后在onCreate里面绑定adapter就可以了

效果如上所示

三：ArrayAdapter，新建一个MyArrayAdapter 重写getView方法

   class MyArrayAdapter extends ArrayAdapter<User>{        public MyArrayAdapter(@NonNull Context context, @LayoutRes int resource, @IdRes int textViewResourceId, @NonNull List objects) {            super(context, 0, 0, objects);        }        @NonNull        @Override        public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {            View row = convertView;            Wrapper wrapper;            if (row == null) {                row = getLayoutInflater().inflate(R.layout.rank_list_item, parent, false);                wrapper = new Wrapper(row);                row.setTag(wrapper);            } else {                wrapper = (Wrapper) row.getTag();            }            TextView tvName = wrapper.gettvName();            TextView tvRank = wrapper.gettvRank();            tvName.setText(al.get(position).getUserName());            tvRank.setText(al.get(position).getUserRank()+"");            return row;        }    }

效果如上所示

三种方法完成了