Android 4.X 的 Http ，利用Thread 和 Handle來更改textView的值

package com.example.http_test;

import java.net.URI;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.*;  //加入widget類別
import android.view.*;    //加入view類別
 


public class MainActivity extends ActionBarActivity {
   
//宣告一個執行緒
    Thread myThread;

TextView t1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
       
   t1 = (TextView)findViewById(R.id.textView1);

//產生新的執行緒並且啟動執行緒
myThread = new myThread();
        myThread.start();

    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

//因為Android 4.X已無法由其他的執行緒來更改主執行緒的UI設定，
//所以必須以Handler來更改主執行緒的UI設定
private Handler mHandler = new Handler() {
        public void handleMessage(Message msg) {
            super.handleMessage(msg);

//只能以Handle來更改textView的值
            t1.setText(msg.getData().toString());
        }
    };
     
   
//新的執行緒
class myThread extends Thread {
        @Override
        public void run() {
            // TODO Auto-generated method stub
            super.run();
           
//Bundle可以在多個執行緒中互相傳遞訊息
            Bundle myBundle = new Bundle();
           
try {
HttpClient client = new DefaultHttpClient();
       URI website = new URI("http://192.168.1.10/test.php");
       HttpGet request = new HttpGet();
       request.setURI(website);

//PHP網頁回傳的資料
       HttpResponse response = client.execute(request);
         HttpEntity resEntity = response.getEntity();
         if(resEntity != null){
   //將Response資料的前100個字以字串的類型代入Bundle
           myBundle.putString("aaa",EntityUtils.toString(resEntity).substring(1,100));
       }
           else{
               myBundle.putString("bbb","Nothing");  
           }            
   
                //以Message資料類型（不能單純以String來傳遞）傳遞資料並呼叫Handler（就是上面自訂的mHandler函數來執行更改ui的值）  
   Message msg = new Message();
                msg.setData(myBundle);
                mHandler.sendMessage(msg);

} catch (Exception e) {
                e.printStackTrace();
            }
}
}
}