android - 无法更改 sdcard（模拟器）的权限，谁能指导我如何更改它们？

Question

我的 sdcard 的权限是 Irwxrwxrwx 我无法在其中推送任何文件 Android Emulator sdcard push error: Read-only file system

如何更改 DDMS / 文件资源管理器 / sdcard 的权限？

在 DDMS (Android) 中更改文件权限

我经历了很多问题，其中一些问题已在上面发布，但没有帮助.. 我什至尝试从朋友那里获取具有读/写权限的图像，但这也无济于事。

Answer 1

有时问题出在更简单的问题上：我的 SD 卡是 FAT32 格式，当我将文件系统更改为 NTFS 时，这个问题就解决了。

Answer 2

You first need to create an SD Card image. This can be done in the AVD Manager at the same time as creating the AVD image.

The SD Card image has to be mounted too (i.e. if you use an already mounted SD Card). When no card is mounted, /sdcard is treated as a folder of /system. So when you try to write to /sdcard on an AVD image without an SD Card mounted it tries to write to /system which is read-only.

Update: Make sure your SD card is mounted correctly. Use adb shell (or adb shell emulator-5554 when your real device is also plugged in) and enter df in the shell.

The output should look like this

Filesystem             Size   Used   Free   Blksize
/dev                   378M    32K   378M   4096
/mnt/asec              378M     0K   378M   4096
/mnt/obb               378M     0K   378M   4096
/system                194M   191M     2M   4096
/data                  194M     8M   185M   4096
/cache                  64M     1M    62M   4096
/mnt/sdcard            246M     6K   246M   512
/mnt/secure/asec       246M     6K   246M   512

Make sure that this two lines are present.

/mnt/sdcard            246M     6K   246M   512
/mnt/secure/asec       246M     6K   246M   512

This means, that the SD Card is mounted correctly.

That being said: DO NOT IN ANY CASES NEVER EVER USE HARDCODED /sdcard/... PATHES. Always use Envirnoment.getExternalStorageDevice() (for multi-user) or Environment.getExternalStoragePublicDirectory (String type) (for public folders accessible to all users)

For Clarification: The SD Card is mounted in a different physical path depending on manufacturer of the ROM. Back when Android first appeared, all external cards where mounted by default in /sdcard since back then all devices had small internal memory and SD-Card slots.

Newer Android Smartphones often ship without an SD Card. The newerones with 1-16 GB internal memory, like tablets, do not mount to /sdcard instead they mount by default to /mnt/sdcard. But it also depends on vendors. One vendor use one way over the other way. Tablets w/o SD Card for example use part of the internal storage to mount to the old /sdcard for compatibility reasons. Always use the API to get the path to internal storage memory!

• Envirnoment | Android Developers

http://developer.android.com/reference/android/os/Environment.html#getExternalStorageDirectory%28%29

or

http://developer.android.com/reference/android/os/Environment.html#getExternalStoragePublicDirectory%28java.lang.String%29