我对getExternalStorageDirectory ()和getExternalStorageState ()之间的区别感到困惑。
对于getExternalStorageState ()，Android文档说：
公共静态字符串getExternalStorageState（）
获取主“外部”存储设备的当前状态。看到
也
getExternalStorageDirectory()
我将阅读有关“外部”存储是否可用的信息，但它返回一个字符串。那是什么字符串呢？如果这是到存储的路径，那么它与
getExternalStorageDirectory()有何不同？将路径返回到被视为“外部”存储的路径？如果不是路径，那么“状态”是什么？有人可以说明一下两者之间的区别是什么，以及为什么您要使用另一种？
最佳答案
从http://developer.android.com/reference/android/os/Environment.html的文档中（请参见顶部的“常量”部分）：
String MEDIA_BAD_REMOVAL getExternalStorageState() returns MEDIA_BAD_REMOVAL if the media was removed before it was unmounted.
String MEDIA_CHECKING getExternalStorageState() returns MEDIA_CHECKING if the media is present and being disk-checked
String MEDIA_MOUNTED getExternalStorageState() returns MEDIA_MOUNTED if the media is present and mounted at its mount point with read/write access.
String MEDIA_MOUNTED_READ_ONLY getExternalStorageState() returns MEDIA_MOUNTED_READ_ONLY if the media is present and mounted at its mount point with read only access.
String MEDIA_NOFS getExternalStorageState() returns MEDIA_NOFS if the media is present but is blank or is using an unsupported filesystem
String MEDIA_REMOVED getExternalStorageState() returns MEDIA_REMOVED if the media is not present.
String MEDIA_SHARED getExternalStorageState() returns MEDIA_SHARED if the media is present not mounted, and shared via USB mass storage.
String MEDIA_UNMOUNTABLE getExternalStorageState() returns MEDIA_UNMOUNTABLE if the media is present but cannot be mounted.
String MEDIA_UNMOUNTED getExternalStorageState() returns MEDIA_UNMOUNTED if the media is present but not mounted.
它返回这些常数之一。
getExternalStorageDirectory()将路径名返回到设备。