B4A Library [class] FileProvider - share files

Edit: FileProvider is included as an internal library now.
After investigating several issues with the current FileProvider code that you can find in the forum, I decided to make some improvements and implement it in a class.

Starting from Android 7 (API 24) you cannot directly share file uris with other applications. You need to use FileProvider.

The FileProvider class should work on all Android versions (4+).

Instructions:

1. Add a reference to FileProvider library.

2. Add to the manifest editor:

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

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" />
)

files-path = File.DirInternal

Current version: 1.00

 

[mddmx]

Erel, THANK YOU VERY MUCH. This works great!

 

[incendio]

Thanks, but there is still an issue with sending mail with attachement.

I make an email body to the code

Sub btnSendEmail_Click
   Dim FileName As String = "b4a.png"
   'copy the shared file to the shared folder
   File.Copy(File.DirAssets, FileName, Starter.Provider.SharedFolder, FileName)
   Dim email As Email
   email.To.Add("aaa@bbb.com")
   email.Subject = "subject"
   email.Body = "This is a test" 'This is the added code
   email.Attachments.Add(Starter.Provider.GetFileUri(FileName))
   email.Attachments.Add(Starter.Provider.GetFileUri(FileName)) 'second attachment
   Dim in As Intent = email.GetIntent
   in.Flags = 1 'FLAG_GRANT_READ_URI_PERMISSION
   StartActivity(in)
End Sub

On my email (gmail), an error message pop up, Unable to attach file.

 

[Erel]

Are you running the example as-is?

 

[incendio]

Are you running the example as-is?

Yes, except for added code for email body.

If code for email body deleted, just like your example, the program runs OK.

 

[Erel]

1. Which Android version?
2. What happens when you click on the other buttons?

 

[incendio]

1. Android oreo 8.0
2. The others buttons were OK

 

[Erel]

Does it work with a single attachment?

 

[scsjc]

I test all, and work fine... really work great.
Thanks !!!

 

[incendio]

Does it work with a single attachment?

No, it didn't.

 

[Erel]

An email intent with a single attachment is the same intent as the share file intent. Lets wait for feedback from other users.

 

[incendio]

There is something strange here.

Here are the steps
1. First clicked on Send Mail -> failed to load attachment
2. Second clicked, without quit application -> worked fine
3. Quit application then clicked again Send mail -> still worked fine
4. Uninstall app, then install again, first clicked -> failed to load attachment, second clicked and so on -> worked fine

I can reproduce the behavior by install and uninstall app.

Any idea, why this is happen ?

Another thing, on Lolipop, there is a shared folder created under DirInternal (i think), but on oreo, there wasn't such folder, where is shared folder created under Oreo?

 

[KMatle]

My apps are ok so far because I copy (file.copy...) the needed files to a folder my app has access to before I share anything or similar. So if the copy works, everything else works. Am I wrong here?

 

[Erel]

@incendio please start a new thread for further discussion. It doesn't look relevant to FileProvider.

My apps are ok so far because I copy (file.copy...) the needed files to a folder my app has access to before I share anything or similar. So if the copy works, everything else works. Am I wrong here?

You must use FileProvider if you want to share any of these files with an intent.

 

[incendio]

@incendio please start a new thread for further discussion. It doesn't look relevant to FileProvider.

Thread created :
https://b4x.com/android/forum/threads/strange-behavior-sending-mail-with-attachment.97897/

Thanks.

 

[GuyBooth]

After investigating several issues with the current FileProvider code that you can find in the forum, I decided to make some improvements and implement it in a class.
Current version: 1.00

How does this relate to the ExternalStorage Class (which contains considerably more code)?

Is its purpose completely different?

 

[Erel]

How does this relate to the ExternalStorage Class (which contains considerably more code)?

They are not related.

FileProvider allows you to share files with other applications using an intent.
ExternalStorage allows your app to access sd cards and usb devices.

 

[GuyBooth]

Ok, thanks for the clarification.

 

[FrankDev]

Hello,

I have a problem with the test program.
Image and text sharing are working fine.
With 'Mail' there is a problem
Android 8.1

Dim in As Intent = email.GetIntent

--------- beginning of main
Copying updated assets files (2)
*** Service (starter) Create ***
Using FileProvider? true
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
Error occurred on line: 58 (Main)
java.lang.ClassCastException: android.net.Uri$HierarchicalUri cannot be cast to java.lang.String
 at anywheresoftware.b4a.phone.Phone$Email.getIntent(Phone.java:677)
 at anywheresoftware.b4a.phone.Phone$Email.GetIntent(Phone.java:694)
 at b4a.examplewewe.main._btnsendemail_click(main.java:430)
 at java.lang.reflect.Method.invoke(Native Method)
 at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
 at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:339)
 at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
 at java.lang.reflect.Method.invoke(Native Method)
 at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:139)
 at anywheresoftware.b4a.BA.raiseEvent2(BA.java:170)
 at anywheresoftware.b4a.BA.raiseEvent(BA.java:166)
 at anywheresoftware.b4a.objects.ViewWrapper$1.onClick(ViewWrapper.java:80)
 at android.view.View.performClick(View.java:6304)
 at android.view.View$PerformClick.run(View.java:24803)
 at android.os.Handler.handleCallback(Handler.java:790)
 at android.os.Handler.dispatchMessage(Handler.java:99)
 at android.os.Looper.loop(Looper.java:171)
 at android.app.ActivityThread.main(ActivityThread.java:6633)
 at java.lang.reflect.Method.invoke(Native Method)
 at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)

 

[Erel]

You need to use a newer version of Phone library. Current version is 2.50.