android Thread

1.Thread的三种形式

第一种：
 class MyThread extends Thread{

        @Override
        public void run(){

            Log.d("MainActivity","i am MyThread");

        }

    }

运行：
//        启动线程
        new MyThread().start();

第二种：
 class MyThread1 implements Runnable{

        @Override
        public void run() {
            Log.d("MainActivity","i am MyThread1");
        }
    }

运行：
 new MyThread1().run();

第三种：
 new Thread(new Runnable() {
            @Override
            public void run() {
                Log.d("MainActivity","i am Thread");
            }
        }).start();

Handler mHandler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what) {
                case 1:
                    progressBar.setVisibility(View.GONE);
                    break;
                case 2:
                    progressBar.setVisibility(View.GONE);
                    break;
                default:
                    break;
            }
        }

    };

Message message = new Message();
                    message.what = 2;
                    mHandler.sendMessage(message);