Android编程学习之异步加载图片的方法

setContentView(R.layout.activity_main); lv = (ListView) findViewById(R.id.lv);

pd = new ProgressDialog(this); pd.setTitle("加载菜单");

pd.setMessage("正在加载"); adapter = new MyAdapter(this);

new MyTask().execute("1"); }

public class MyTask extends AsyncTask<String, Void, List<Menu>> { @Override

protected void onPreExecute() { super.onPreExecute();

pd.show(); }

@Override protected void onPostExecute(List<Menu> result) {

super.onPostExecute(result); adapter.setData(result);

lv.setAdapter(adapter); pd.dismiss();

} @Override

protected List<Menu> doInBackground(String... params) { String menuListStr = getListDishesInfo(params[0]);

return Utils.getInstance().parseMenusJSON(menuListStr); }

} private String getListDishesInfo(String sortId) {

// url String url = HttpUtil.BASE_URL + "servlet/MenuInfoServlet?sortId="

+ sortId + "&flag=1"; // 查询返回结果

return HttpUtil.queryStringForPost(url); }

}

(2)、activity_main.xml的布局文件如下：