Android开发学习之路-使用Handler和Message更新UI

 public class MainActivity extends Activity implements OnClickListener {
     private static final int UPDATE_TEXT = 1;
     private Button send;
     private TextView tv;
     
     private Handler hd = new MyHandler();
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         send = (Button) findViewById(R.id.bt_sendMessage);
         tv = (TextView) findViewById(R.id.tv_text);
         send.setOnClickListener(this);
     }
 
     @Override
     public void onClick(View v) {
         switch (v.getId()) {
         case R.id.bt_sendMessage:
             new Thread(new Runnable() {
                 @Override
                 public void run() { //　新创建一个进程，并新创建一个Message的目标，是用Handler的目标推送这一Message
                     Message msg = new Message();
                     msg.what = UPDATE_TEXT; // 客户自定的一个值，用以标志不一样种类的信息
                     hd.sendMessage(msg); // 推送信息
                 }
             }).start();
             break;
 
         default:
             break;
         }
     }
     
     // 界定一个内部类承继自Handler，而且遮盖handleMessage方式用以解决子进程传出去的信息
     class MyHandler extends Handler{
         @Override
         public void handleMessage(Message msg) {
             super.handleMessage(msg);
             switch (msg.what) {
             case UPDATE_TEXT: // 接纳到信息以后，对UI控制开展改动
                 tv.setText("改动取得成功！");
                 break;
 
             default:
                 break;
             }
         }
     }
 }