Activity界面 刷新 状态提示

Activity界面 刷新 状态提示，在线等
我进一Activity时，此界面开始会取服务器数据，然后显示到界面上来，所以当数据显示出来时，会有点加载时间，（默认情况下，界面右上角，有 刷新 二字）

现需：  
  1 刚进界面时，当数据正在加载时，在界面右上角用一 正在刷新或正在加载的 图标 来提示，当数据加载完成后，又显示默认时的 刷新 二字
  2 当页面数据加载完成后，再点击右上角的 刷新 处，右上角 又出现 正在刷新或正在加载的图片，直到数据加载完成

这如何实现呀，能给个demo就更好， 350038760@qq.com thanks

[解决办法]
线程+handler吧，有时间的话写个demo吧
[解决办法]
Android有异步任务啊！
[解决办法]

Java code

pDialog = new ProgressDialog(ParkListActivity.this);        pDialog.setMessage("获取数据中,请稍等...");        handler = new Handler() {            @Override            public void handleMessage(Message msg) {                super.handleMessage(msg);                pDialog.dismiss();                if (msg.what == 0) {                    Toast.makeText(ParkListActivity.this, "获取数据失败", Toast.LENGTH_LONG)                            .show();                } else {                    if (msg.obj == null) {                        Toast.makeText(ParkListActivity.this, "获取数据失败",                                Toast.LENGTH_LONG).show();                    } else {                        ParkListReturnInfo parkListReturnInfo = null;                        parkListReturnInfo = (ParkListReturnInfo) msg.obj;                        if (parkListReturnInfo != null                                && parkListReturnInfo.getReturnCode() != null                                && parkListReturnInfo.getReturnCode().equals(                                        "0")) {                                                        list1 = parkListReturnInfo.getParkListReturnData();                            mantitle.setText(area+"区"+parkName+"共搜索到"+list1.size()+"个停车场");                            if (list1 != null && list1.size() > 0) {                                                                Map<String, Object> map;                                Iterator<ParkListReturnData> it = list1                                        .iterator();                                while (it.hasNext()) {                                    ParkListReturnData parkListReturnData1 = it                                            .next();                                    map = new HashMap<String, Object>();                                    map.put("name", parkListReturnData1                                            .getParkName());                                    map.put("sex", parkListReturnData1                                            .getFreeSeat());                                    map.put("dfs", parkListReturnData1                                            .getOrderFreeSeat());                                    map.put("aaa", parkListReturnData1                                            .getParkId());                                    System.out.println("88888888888"                                            + parkListReturnData1.getParkId());                                    listput.add(map);                                    // parkListReturnData1.getParkId();                                }                            }                            listadapter = new ListAdapter(ParkListActivity.this,                                    listput);                            listView.setAdapter(listadapter);                        } else {                            Toast.makeText(ParkListActivity.this,                                    parkListReturnInfo.getReturnName(),                                    Toast.LENGTH_LONG).show();                        }                    }                }                pDialog.dismiss();            }        };        pDialog.show();        QueryThread th = new QueryThread(this.handler);        th.start(); 
 
[解决办法]
Java code
public class ParkListActivity extends CommonActivity {    ListView listView;    public static List<Map<String, Object>> listput;    ListAdapter listadapter;    ProgressDialog pDialog;    TextView title;    TextView mantitle;    Handler handler;@Override    public void onCreate(Bundle savedInstanceState) {                setContentView(R.layout.park_list);pDialog = new ProgressDialog(ParkListActivity.this);        pDialog.setMessage("获取数据中,请稍等...");        handler = new Handler() {            @Override            public void handleMessage(Message msg) {                super.handleMessage(msg);                pDialog.dismiss();                if (msg.what == 0) {                    Toast.makeText(ParkListActivity.this, "获取数据失败", Toast.LENGTH_LONG)                            .show();                } else {                    if (msg.obj == null) {                        Toast.makeText(ParkListActivity.this, "获取数据失败",                                Toast.LENGTH_LONG).show();                    } else {                        ParkListReturnInfo parkListReturnInfo = null;                        parkListReturnInfo = (ParkListReturnInfo) msg.obj;                        对后台的数据进行处理（省略）                    }                }                pDialog.dismiss();            }        };        pDialog.show();        QueryThread th = new QueryThread(this.handler);        th.start();｝class QueryThread extends Thread {        private Handler handler;        private ParkClient parkClient;        private ParkListReturnInfo parkListReturnInfo;        private ParkListInfo parkListInfo;        private Message msg;        public QueryThread(Handler handler) {            this.handler = handler;        }        @Override        public void run() {                            msg = new Message();                                parkListReturnInfo = parkClient.getParkList(parkListInfo);//获取后台数据                msg.obj = parkListReturnInfo;                msg.what = 1;            } catch (Exception e) {                msg.what = 0;                e.printStackTrace();            }  finally {                handler.sendMessage(msg);            }        }    }｝
[解决办法]
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Java code

public class ParkListActivity extends CommonActivity {
    ListView listView;
    public static List<Map<String, Object>> listput;

    ListAdapter listadapter;
    ProgressDialog pDialog……