Handler更新UI的三种方式

public class MainActivity extends Activity {

private TextView text;
private Handler handler = new Handler();

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

    /**
     * new Thread()在该线程中实现你具体的业务逻辑，比如网络请求，耗时操作等等；
     * new Thread()是一个子线程，是非UI线程，如果在该线程中需要更新界面，则需要使用Handler；
     *
     */
    new Thread() {
        @Override
        public void run() {//在run()方法实现业务逻辑；
            //...

            //更新UI操作；
            handler.post(new Runnable() {
                @Override
                public void run() {
                    text.setText(使用Handler更新了界面);
                }
            });

        }
    }.start();
}}

public class MainActivity extends Activity {

private TextView text;
private Handler handler = new Handler();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    text = (TextView) findViewById(R.id.id_text);
    final MyRunnable myRunnable = new MyRunnable();//定义MyRunnable的对象；

    new Thread() {

        @Override
        public void run() {
            handler.post(myRunnable);//调用Handler.post方法；
        }
    }.start();
}

class MyRunnable implements Runnable {//内部类实现Runnable接口；

    @Override
    public void run() {//还是在Runnable重写的run()方法中更新界面；
        text.setText(使用Handler更新了界面);
    }
}}

public class MainActivity extends Activity {

private TextView text;
private Handler handler = new Handler() {

    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
            case 1:
                text.setText(使用Handler更新了界面);
                break;
        }
    }
};

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

    new Thread() {

        @Override
        public void run() {
            //...你的业务逻辑；
            Message message = new Message();//发送一个消息，该消息用于在handleMessage中区分是谁发过来的消息；
            message.what = 1;
            handler.sendMessage(message);
        }
    }.start();
}}