Android Question Mysterious File.exists

[Guenter Becker]

Hello,

I hace this code in my project

If File.Exists(File.DirAssets,Theme) Then
    l = File.Readlist(File.DirAssets,Theme)
End If

I checked that the File called BlueTheme.TD is present in the Files folder and the folder is synchronized.
I replace the variable Theme with the full Filename "BlueTheme.TD".
I tested my project on my phone and on the emulator (Android 34).
I tested the code in different new projects.

I always got the Problem that File.exists is reporting false? Why does it not find the file?
Does ony one has an answer what goes wrong.

 

[agraham]

As I understand it you can't use File.Exists with DirAssets as it it is a virtual folder, not a real one. As your project includes the files in DirAssets you should already know which files are included.

 

[Guenter Becker]

Ok, my fault. Thank you agraham.

 

[walt61]

It works in B4A, but not in B4J. Use lowercase characters only for your filename and it will work:

    ' 2 files in Files: "BlueTheme.TD" and "bluetheme2.td":
    Log(File.Exists(File.DirAssets, "BlueTheme.TD")) ' False
    Log(File.Exists(File.DirAssets, "bluetheme2.td")) ' True

This way it will work for both products:

#If B4A
Public Sub FileExistsInDirAssets(fname As String) As Boolean 'Tags: [files]

    Return File.Exists(File.DirAssets, fname)

End Sub
#Else If B4J
' Library dependencies: Reflection
Public Sub FileExistsInDirAssets(fname As String) As Boolean 'Tags: [files]

    ' Code based on https://www.b4x.com/android/forum/threads/file-exists-on-dirassets.138614

    Dim r As Reflector
    r.Target = Me
    r.Target = r.RunMethod("getClass")
    Dim In As InputStream = r.RunMethod2("getResourceAsStream", "/Files/" &  fname, "java.lang.String")
    If In.IsInitialized = False Then Return False
    In.Close
    Return True

End Sub
#End If

 

[Guenter Becker]

It works in B4A, but not in B4J. Use lowercase characters only for your filename and it will work:

    ' 2 files in Files: "BlueTheme.TD" and "bluetheme2.td":
    Log(File.Exists(File.DirAssets, "BlueTheme.TD")) ' False
    Log(File.Exists(File.DirAssets, "bluetheme2.td")) ' True

This way it will work for both products:

#If B4A
Public Sub FileExistsInDirAssets(fname As String) As Boolean 'Tags: [files]

    Return File.Exists(File.DirAssets, fname)

End Sub
#Else If B4J
' Library dependencies: Reflection
Public Sub FileExistsInDirAssets(fname As String) As Boolean 'Tags: [files]

    ' Code based on https://www.b4x.com/android/forum/threads/file-exists-on-dirassets.138614

    Dim r As Reflector
    r.Target = Me
    r.Target = r.RunMethod("getClass")
    Dim In As InputStream = r.RunMethod2("getResourceAsStream", "/Files/" &  fname, "java.lang.String")
    If In.IsInitialized = False Then Return False
    In.Close
    Return True

End Sub
#End If

Thank you this works. How should one know to use only lowercase? I hate Trial and Error.