android文件系统，可以浏览文件，创建文件与目录，删除文件与目录。-android file system, can browse files, create files and directories, delete files and directories.

android联系人详细代码,根据情况看看，-android Contact demos

In the world of Android, an Activity is the point at which you make contact with your users. It s a screen where you capture and present information to the user. You can construct your Activity screens by using either: XML layout files or hard-