Android Question File.WriteString Problem

[wdegler]

To anyone with an explanation:

I clicked on Help/Online Help, selected File/WriteString and copied the example:

File.WriteString(File.DirRootExternal, "1.txt", "Some text")

into a program as the first statement after the LoadLayout line.
I then set a breakpoint on the line after that. After I clicked on Project/Compile & Run,
the program stopped at the breakpoint and the following run time error message appeared:

java.io.FileNotFoundException: /mnt/sdcard/1.txt (Permission denied)

Why doesn't WriteString work here?

 

[lemonisdead]

Could you try by adding in the Manifest

Edit

AddPermission(android.permission.WRITE_EXTERNAL_STORAGE)

 

[Erel]

Note that the permission is added automatically when you access File.DirRootExternal.

You can check whether the external storage is writable with File.ExternalWritable.

 

[wdegler]

Could you try by adding in the Manifest

Edit

AddPermission(android.permission.WRITE_EXTERNAL_STORAGE)

I added this line you suggested to the manifest. The same same error appears when I recompile and run.

 

[wdegler]

Note that the permission is added automatically when you access File.DirRootExternal.

You can check whether the external storage is writable with File.ExternalWritable.

I added this File.ExternalWritable line as you suggested. It responded with False.
I am running this app in the Debug mode using the built-in virtual device manager.

I have written and published previous apps with a File.WriteString(File.DirRootExternal, "1.txt", "Some text") kind of statement without a problem.
Could the fact that they were compiled with a previous version of B4A be a factor?

I find that there is no problem when I use File.DirInternal in place of File.DirRootExternal.

 

[Cableguy]

Have you defined a virtual SDCard for your emulated device?

 

[Erel]

Could the fact that they were compiled with a previous version of B4A be a factor?

No. It is not related to B4A. The file system is read-only for some reason.

The best solution is to avoid using the emulator.

 

[wdegler]

Have you defined a virtual SDCard for your emulated device?

Have you defined a virtual SDCard for your emulated device?

Thanks. I haven't thought of that before.
One of my previous apps (published), contains all of the following lines which work as intended:

File.WriteString(File.DirRootExternal,"Settings.txt",DefSetting)

File.WriteList(File.DirRootExternal,"Log.txt",LogLst)

If File.Exists(File.DirRootExternal,"Settings.txt") Then
Settings=File.ReadString(File.DirRootExternal,"Settings.txt")
Else
File.WriteString(File.DirRootExternal,"Settings.txt",DefSetting)

Settings=DefSetting
EndIf

LogLst=File.ReadList(File.DirRootExternal,"Log.txt")

File.Delete(File.DirRootExternal,"Log.txt").


I see in the documentation that DirRootExternal, DirInternal and DirDefaultExternal are labeled as read only. ???

 

[wdegler]

No. It is not related to B4A. The file system is read-only for some reason.

The best solution is to avoid using the emulator.

Thank you Erel for the advice. I will consider it.

 

[Cableguy]

I see in the documentation that DirRootExternal, DirInternal and DirDefaultExternal are labeled as read only. ???

Yes, they only provide "easy to reference" path for the standard folders.