Android——Handler 多线程

java

打开界面 实现图片轮播

 //Handler

        final ImageView iv_2 = (ImageView)findViewById(R.id.iv_2);

        final int[] imageid = {R.drawable.dazhong,R.drawable.deskclock,R.drawable.gallery,R.drawable.maps,
                R.drawable.mm,R.drawable.netease,R.drawable.qq,R.drawable.sinaweibo};


        //继承Handler
        final Handler handler = new Handler()
        {
            int i = 0;
            //处理信息的回调方法
            //重写

            @Override
            public void handleMessage(Message msg) {
                super.handleMessage(msg);

                if (msg.what == 1)
                {
                    //切换图片
                    iv_2.setImageResource(imageid[i++ %imageid.length]);
                }
            }
        };

        //在新线程里发送消息
        //定时循环发送
        //定时器：启动新线程，定时执行代码
        new Timer().schedule(new TimerTask() {
            @Override
            public void run() {

                //发送消息
                //空消息
                handler.sendEmptyMessage(1);
            }
        },3000,2000);
    }