java - getExternalStorageDirectory()和getExternalStorageState()的区别

Question

我对 getExternalStorageDirectory () 和 getExternalStorageState () 之间的区别有点困惑。

对于 getExternalStorageState ()，Android 文档说:

public static String getExternalStorageState ()

Gets the current state of the primary "external" storage device. See Also

getExternalStorageDirectory()

我会阅读这篇关于“外部”存储是否可用的文章，但它返回一个字符串。那么它是什么字符串呢？如果它是存储路径，那么它与 getExternalStorageDirectory() 有何不同，后者返回被视为“外部”存储的路径？如果不是路径，“状态”是什么？

有人可以澄清一下区别是什么，为什么你会使用一个而不是另一个？

Answer 1

来自 http://developer.android.com/reference/android/os/Environment.html 处的文档(请参阅顶部的常量部分):

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.

它返回这些常量之一。

getExternalStorageDirectory() 返回设备的路径名。