/*查阅api ---context
1.abstract AssetManager getAssets()
Returns an AssetManager instance for the application's package.
得到assets目录下的资源
2.abstract File getCacheDir()
Returns the absolute path to the application specific cache directory on the filesystem.
得到缓存目录
3.abstract PackageManager getPackageManager()
Return PackageManager instance to find global package information.
得到包名 版本号的一些信息
4.abstract String getPackageName()
Return the name of this application's package.
abstract String getPackageResourcePath()
Return the full path to this context's primary Android package.
5.
abstract FileInputStream openFileInput(String name)
Open a private file associated with this Context's application package for reading.
abstract FileOutputStream openFileOutput(String name, int mode)
Open a private file associated with this Context's application package for writing.
*/
/*toast*/
1.Toast.makeText(mtext,"Stri ng",Toast.选时间).show
2.mcontext=this ，就是创建一个数据
/*SharedPreferences
Developer Guides
For more information about using SharedPreferences, read the Data Storage developer guide. 从这里跳转进去看例子，详细信息
*/