哪位大神帮我看看ListView上的数据不能实时更新

package org.lhm.laofengxiang;




import java.util.*;
import cn.yljd.service.MyXMLParser;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.text.Html;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.*;


public class Jjtz extends Activity {
MyXMLParser parser=new MyXMLParser();
static int size = 14;
private ListView list;
private MyAdapter myAda;
ArrayList<HashMap<String,Object>> arrayList=new ArrayList<HashMap<String,Object>>();
public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.jjtzsummary);  
       list=(ListView)findViewById(R.id.jjtzlist);
       list.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {        
        myAda.Login(arg2);
        
}
});
       List<String[]> list1=parser.xml2list("http://203.86.16.92:8000/ProduceManager.asmx/selectJjtz", "diffgr:diffgram/NewDataSet/Table", "dm,mc,lsj,dhj");       
for(String[] str:list1){
HashMap<String, Object> map = new HashMap<String, Object>();
map.put("dm", str[0]);
map.put("mc", str[1]);
map.put("lsj", str[2].substring(0, str[2].length()-2));
map.put("dhj", str[3].substring(0, str[3].length()-2));
arrayList.add(map);
myAda = new MyAdapter(this, arrayList, size);
   list.setAdapter(myAda);
   myAda.notifyDataSetChanged();
}


ZoomControls zoomControls = (ZoomControls) findViewById(R.id.zoomcontrols);
   zoomControls.setOnZoomInClickListener(new OnClickListener() {
   public void onClick(View v) {
   size = size + 2;
   myAda = new MyAdapter(Jjtz.this, arrayList, size);   
   list.setAdapter(myAda);
   myAda.notifyDataSetChanged();
   }
   });
   zoomControls.setOnZoomOutClickListener(new OnClickListener() {
   public void onClick(View v) {
   size = size - 2;
   myAda = new MyAdapter(Jjtz.this, arrayList, size);
   list.setAdapter(myAda);
   myAda.notifyDataSetChanged();    
   }
   });
}  


private class MyAdapter extends BaseAdapter {
ArrayList<HashMap<String, Object>> data;
Context context;
int size;
public MyAdapter(Context context,
ArrayList<HashMap<String, Object>> data, int size) {
this.context = context;
this.data = data;
this.size = size;
}
public int getCount() {
return data.size();
}
public Object getItem(int position) {
return data.get(position);
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = LayoutInflater.from(context);
convertView = inflater.inflate(R.layout.jjtzsummaryresult, null);
TextView dm = (TextView) convertView.findViewById(R.id.dm);
TextView mc = (TextView) convertView.findViewById(R.id.mc);
TextView lsj = (TextView) convertView.findViewById(R.id.lsj);
TextView dhj = (TextView) convertView.findViewById(R.id.dhj);
dm.setTextSize(size);
mc.setTextSize(size);
lsj.setTextSize(size);
dhj.setTextSize(size);
dm.setText(data.get(position).get("dm").toString());
mc.setText(data.get(position).get("mc").toString());
lsj.setText(data.get(position).get("lsj").toString());
dhj.setText(data.get(position).get("dhj").toString());
return convertView;
}
public void Login(final int arg2) {

LayoutInflater factory=LayoutInflater.from(Jjtz.this);
final View v1=factory.inflate(R.layout.jjtzdialog,null);
AlertDialog.Builder dialog=new AlertDialog.Builder(Jjtz.this);
dialog.setTitle("修改金价");
dialog.setView(v1);
       dialog.setPositiveButton("确定修改", new DialogInterface.OnClickListener() {
           public void onClick(DialogInterface dialog, int whichButton) { 
               //修改金价
            try{
            EditText lsj=(EditText) v1.findViewById(R.id.lsj);
            EditText dhj=(EditText) v1.findViewById(R.id.dhj);            
            String lsjStr = lsj.getText().toString().trim();
 String dhjStr = dhj.getText().toString().trim();
 String dm=data.get(arg2).get("dm").toString();
 List<String[]> list=parser.xml2list("http://203.86.16.92:8000/ProduceManager.asmx/updateJjtz?lsj="+lsjStr+"&dhj="+dhjStr+"&dm="+dm+"", "diffgr:diffgram", "");
            }catch(Exception e){
            e.printStackTrace();
            }
           }
       });
       dialog.setNegativeButton("取消修改",new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
 
}
});
       dialog.show();
}

}

}

觉得写得不错，帮忙打赏下，谢谢！