1.handler具体使用
https://www.cnblogs.com/JohnTsai/p/5259869.html

2.handlerThread用法
https://www.jianshu.com/p/e9b2c0831b0d
http://blog.csdn.net/double2hao/article/details/58598171
http://blog.csdn.net/lmj623565791/article/details/47079737

3.Android主线程、子线程通信（Thread+handler） 总结

4.post和sendMessage
http://blog.csdn.net/u013168615/article/details/47024073

5.sendEmptyMessage(int)' on a null object reference
初始crash，mainHandler中初始化在子线程之后
https://www.imooc.com/qadetail/140712
http://blog.csdn.net/rodulf/article/details/50910356