https://my.oschina.net/rengwuxian/blog/181449

http://www.jianshu.com/p/cb9b4b71a820

http://blog.csdn.net/u014665060/article/details/55820435

http://www.cnblogs.com/baiqiantao/p/10f7070ba7800d9f81bf76002958919c.html

http://blog.csdn.net/lincyang/article/details/46875157

Handler使用中可能引发的内存泄漏