首先建立一個Handler

private Handler handler=new Handler(){
    @Override
    public void handleMessage(Message msg){
        switch(msg.what){
            case 1:
                imageView.setImageBitmap((Bitmap) msg.obj);
                break;
        }
    }
};

然後非同步載入網路圖片

Thread thread = new Thread(){
    public void run(){
        try {
            String path="http://n.sinaimg.cn/news/1_img/upload/8de453bf/20170301/f2KQ-fyawhqy3351967.jpg"
 
;
            URL url=new URL(path);
            HttpURLConnection connection= (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            connection.setConnectTimeout(5000);
            connection.setReadTimeout(8000);
            connection.connect();
            if(connection.getResponseCode
 
()==200){
                InputStream inputStream=connection.getInputStream();
                Bitmap bitmap= BitmapFactory.decodeStream(inputStream);

                Message msg=Message.obtain();

                msg.obj=bitmap;
                msg.what=1;
                handler.sendMessage(msg);
            }else{
                Message msg=Message.obtain
 
();
                msg.what=2;
                handler.sendMessage(msg);

            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
};
thread.start();
break;