Android Question WRITE_EXTERNAL_STORAGE error

[hanyelmehy]

i use this in manifest

AddManifestText(
<uses-sdk android:minSdkVersion="9" android:targetSdkVersion="23"/>
AddManifestText(
<uses-permission
  android:name="android.permission.WRITE_EXTERNAL_STORAGE"
  android:maxSdkVersion="18" />
)
AddManifestText(
<uses-permission
  android:name="android.permission.READ_EXTERNAL_STORAGE"
  android:maxSdkVersion="18" />
)

When check for

RP.Check(RP.PERMISSION_WRITE_EXTERNAL_STORAGE)

return true
and when i try to copy file to EXTERNAL_STORAGE i get

(ErrnoException) android.system.ErrnoException: open failed: EACCES (Permission denied)

test done with B4A 6.3 and android 6.0

 

[Erel]

1. It is almost always a mistake to call RP.Check. You should use RP.CheckAndRequest and continue the program flow from the PermissionResult event.
2. Your code is wrong. You have confused two different things. If you set the maxSdkVersion to the permission then you need to use RuntimePermission.GetSafeDirDefaultExternal.

 

[hanyelmehy]

1. It is almost always a mistake to call RP.Check. You should use RP.CheckAndRequest and continue the program flow from the PermissionResult event.
2. Your code is wrong. You have confused two different things. If you set the maxSdkVersion to the permission then you need to use RuntimePermission.GetSafeDirDefaultExternal.

Thank you for your answer
i get no 1
i still have confused about no 2 :
in my app ,after download a file i save it to (File.DirInternalCache) ,and i asked user to save it in any other place if he want ,what is your recommendation to do that ,because i have above problem if user select external storage path

 

[Erel]

If you want to allow the user to choose File.DirRootExternal then you should remove this section from the manifest editor:

AddManifestText(
<uses-permission
 android:name="android.permission.WRITE_EXTERNAL_STORAGE"
 android:maxSdkVersion="18" />
)
AddManifestText(
<uses-permission
 android:name="android.permission.READ_EXTERNAL_STORAGE"
 android:maxSdkVersion="18" />
)

 

[hanyelmehy]

If you want to allow the user to choose File.DirRootExternal then you should remove this section from the manifest editor:

AddManifestText(
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE"
android:maxSdkVersion="18" />
)
AddManifestText(
<uses-permission
android:name="android.permission.READ_EXTERNAL_STORAGE"
android:maxSdkVersion="18" />
)

so i well use only

AddPermission(android.permission.WRITE_EXTERNAL_STORAGE)
AddPermission(android.permission.READ_EXTERNAL_STORAGE)

because when i use this and test on android 6 i get java.io.FileNotFoundException: /mnt/m_external_sd/file name: open failed: EACCES (Permission denied)

 

[hanyelmehy]

also what is the behavior for

RP.CheckAndRequest(RP.PERMISSION_WRITE_EXTERNAL_STORAGE)
RP.CheckAndRequest(RP.PERMISSION_READ_EXTERNAL_STORAGE)

when app run on android 4.0 when targetSdkVersion is set to 23 or above.
and use

AddPermission(android.permission.WRITE_EXTERNAL_STORAGE)
AddPermission(android.permission.READ_EXTERNAL_STORAGE)

 

[Erel]

1. You don't need to add the permissions yourself. They will be added automatically.

2. You need to call CheckAndRequest before you can access File.DirRootExternal or File.DirDefaultExternal.

also what is the behavior for

See "the method logic" section: https://www.b4x.com/android/forum/threads/runtime-permissions-android-6-0-permissions.67689/