AsyncTask onPreExecute方法用于在执行后台任务前做一些UI操作

1.实例化

TableListsTask task = new TableListsTask(ServerIP,"ALL", MenuActivity.this);
  //第三参数建立上下文关系

2.TableListsTask.java

package com.realhope.rmeal.ui;

import static com.realhope.rmeal.service.ConstantUtil.SERVER_ADDRESS;

import static com.realhope.rmeal.service.ConstantUtil.SERVER_PORT;

import android.content.Context; import android.os.AsyncTask;

import android.util.Log;

import com.realhope.rmeal.bean.TableLists;

import com.realhope.rmeal.util.MyUtil;

/**异步任务  方法：menuactivity 获取台列表   * 2014-7-31   * @author Wucy   *   */

public class TableListsTask extends AsyncTask<String, Integer, String> {

//onPreExecute方法用于在执行后台任务前做一些UI操作

private static final String TAG = "ASYNC_TableListsTASK";

private MyConnector mc = null;

private final Context mContext;

String mtable_no,mServerIP;

public TableListsTask(String ServerIP,String table_no,  Context context){

super();

mContext = context;

mtable_no =table_no;

mServerIP=ServerIP;   }

@Override

protected void onPreExecute() {

Log.i(TAG, "onPreExecute() called");          // MyUtil.showToast(OrderActivity.this, "数据上传...");         // textView.setText("loading...");             //button_toOrder.setText("正在查询....");      }

//doInBackground方法内部执行后台任务,不可在此方法内修改UI

@Override

protected String doInBackground(String... params) {

Log.i(TAG, "doInBackground(Params... params) called");

try{

if(mc == null){

mc = new MyConnector(mServerIP, SERVER_PORT);

}

String msg = "<#GET_TABLELIST#>"+ mtable_no;

mc.dout.writeUTF(msg); //发出获取台表请求

mc.dout.flush();

int size = mc.din.readInt();   //获取个数

mc.dout.writeUTF("<#READY_TO_READ_COMMENT#>");

mc.dout.flush();

for(int i=0;i<size;i++){

msg = mc.din.readUTF();  //读取每条信息

String [] sa = msg.split("\\|"); //切割字符串

TableLists tablelists = new TableLists(Integer.valueOf(sa[0]),Integer.valueOf(sa[1]),sa[2],Integer.valueOf(sa[3]),Integer.valueOf(sa[4]),Integer.valueOf(sa[5]));

((MenuActivity)mContext).lstDate_TableLists.add(tablelists);

}

mc=null;

return  String.valueOf(1);

} catch (Exception e) {

Log.e(TAG, e.getMessage());                        }

return null;

}                                                                                                                                                         //onProgressUpdate方法用于更新进度信息                                       @Override

protected void onProgressUpdate(Integer... progresses) {

Log.i(TAG, "onProgressUpdate(Progress... progresses) called");

}                                                                                                                                                         //onPostExecute方法用于在执行完后台任务后更新UI,根据后台下单结果重新绑定前台订单                     @Override

protected void onPostExecute(String result) {

Log.i(TAG, "onPostExecute(Result result) called");

MyUtil.showToast(mContext, "取后台开台信息数据");

((MenuActivity)mContext).updateTableLists();                                         }                                                                                                                                                      //onCancelled方法用于在取消执行中的任务时更改UI

@Override

protected void onCancelled() {

Log.i(TAG, "onCancelled() called");

}

}