Android Question Files in the user folder (OS12.0-API 31)

[Sergey_New]

The user created a folder "MyFolder" and placed several text files with the extension *.ged in it.
How can I programmatically get a list of these files without using the file manager built into the device?
I believe that they need to be copied to a safe place and worked with them there.
I don’t know yet how this can be done. Please help.

 

[arjian]

    Dim ListOfFiles As List,i As Int
    Dim FileName As String
    
    ListOfFiles.Initialize
    
    ListOfFiles.AddAll(File.ListFiles(File.DirDefaultExternal & "/Downloads" ))  '-- set MyFolder adress base on it's location
    
    For i=0 To ListOfFiles.Size-1
        FileName=ListOfFiles.Get(i)
        If FileName.EndsWith(".ged") Then
            '-- code
        End If
    Next

 

[Sergey_New]

arjian, an exception occurs at the line:

ListOfFiles.AddAll(File.ListFiles(File.DirDefaultExternal & "/Downloads" ))

java.io.IOException: /storage/emulated/0/Android/data/sv.bystrovzorov/files/Download is not a folder.
On my emulator the folder is called Download, but in both cases the error repeats.

 

[DonManfred]

You do not have access to this folder.
Check

android.jar / targetSdkVersion / minSdkVersion

There are several versioned components that affect the compilation process and the runtime behavior of our apps. The purpose of this tutorial is to explain the differences between them and help you choose which version to use. Each Android version is mapped to an api level. You can see this...

www.b4x.com

and

[B4X] Features that Erel recommends to avoid

Many things have changed in B4X and also in the underlying platforms. I will try to list here all kinds of (old) features that have better alternatives. B4X is backward compatible so these features still work. The recommendations are more relevant for new projects or when implementing new...

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[arjian]

arjian, an exception occurs at the line:

ListOfFiles.AddAll(File.ListFiles(File.DirDefaultExternal & "/Downloads" ))

java.io.IOException: /storage/emulated/0/Android/data/sv.bystrovzorov/files/Download is not a folder.
On my emulator the folder is called Download, but in both cases the error repeats.

first of all you need have access to read files
the second you need to set your folder location correctly

for example i created a folder (MyFolder) on my phone so now i can get list of files in that folder with this code

Dim ListOfFiles As List,i As Int
    Dim FileName As String
    
    
    ListOfFiles.Initialize
    ListOfFiles.AddAll(File.ListFiles("/storage/emulated/0/MyFolder" ))
    
    For i=0 To ListOfFiles.Size-1
        FileName=ListOfFiles.Get(i)
        Log("file " & (i+1) & " : " & FileName)
    Next

 

[Sergey_New]

first of all you need have access to read files

The manifest has read permission set. The files are not readable.

Spoiler: manifest

AddManifestText(
<uses-sdk android:minSdkVersion="28" android:targetSdkVersion="33"/>
<supports-screens android:largeScreens="true"
android:normalScreens="true"
android:smallScreens="true"
android:anyDensity="true"/>)
SetApplicationAttribute(android:icon, "@drawable/icon")
SetApplicationAttribute(android:label, "$LABEL$")
SetApplicationAttribute(android:theme, "@android:style/Theme.Holo.Light")
SetActivityAttribute(ListEvents, android:excludeFromRecents, true)
SetApplicationAttribute(android:requestLegacyExternalStorage, true)
AddActivityText(Main,
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.DEFAULT"/>
</intent-filter>
)
AddManifestText(<permission
android:name="$PACKAGE$.permission.MAPS_RECEIVE"
androidrotectionLevel="signature"/>
<uses-feature android:glEsVersion="0x00020000" android:required="true"/>)
CreateResourceFromFile(Macro, FirebaseAnalytics.GooglePlayBase)

AddApplicationText(
<uses-library
android:name="org.apache.http.legacy"
android:required="false" />
)

AddPermission(android.permission.ACCESS_NETWORK_STATE)
AddPermission(android.permission.WRITE_EXTERNAL_STORAGE)

AddApplicationText(
<provider
android:name="android.support.v4.content.FileProvider"
android:authorities="$PACKAGE$.provider"
android:exported="false"
android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/provider_paths"/>
</provider>
)

CreateResource(xml, provider_paths,
<files-path name="name" path="shared" />
)
CreateResourceFromFile(Macro, Themes.LightTheme)
CreateResource(values-v21, theme.xml,
<resources>
<style name="LightTheme" parent="@android:style/Theme.Material.Light">
<item name="android:textAllCaps">false</item>
</style>
</resources>
)

 

[DonManfred]

for example i created a folder (MyFolder) on my phone so now i can get list of files in that folder with this code

You ARE using targetSDK 31+? I guess NO

 

[arjian]

You ARE using targetSDK 31+? I guess NO

Min 5 and target is 31

 

[Sergey_New]

Min 5 and target is 31

Could you make a short example on B4A only? Thank you!

 

[DonManfred]

Min 5 and target is 31

the Device you are running this on has which Android-Version?

 

[arjian]

the Device you are running this on has which Android-Version?

1-Poco F3 with android 13
2-Emulator with android 12

 

[arjian]

Could you make a short example on B4A only? Thank you!

 

[Sergey_New]

Thank you!
Unfortunately, the files cannot be read on the emulator. If you create a “Media” subfolder in the MyFolder folder, it will be displayed. This means there is access to the MyFolder folder, but not to the files.
An exception occurs on the Samsung S7 device:
Error occurred on line: 47 (Main)
java.lang.RuntimeException: Object should first be initialized (List).

 

[arjian]

Thank you!
Unfortunately, the files cannot be read on the emulator. If you create a “Media” subfolder in the MyFolder folder, it will be displayed. This means there is access to the MyFolder folder, but not to the files.
An exception occurs on the Samsung S7 device:
Error occurred on line: 47 (Main)
java.lang.RuntimeException: Object should first be initialized (List).

Copy a random file to MyFolder then run app again
By the way don't forget to initialize the list variable
There's a line in code (ListofFilles.initialize) for that

 

[Sergey_New]

Для этого в коде есть строка (ListofFilles.initialize).

В вашем случае это не так. В строке 43 есть: ListOfFiles.Initialize.
Я скопировал файл еще раз. Никаких изменений нет.

 

[arjian]

you are right , the code just returns folder list not file list

 

[Sergey_New]

Isn't there already a solution to this problem?