TDirectory.GetFiles() is not working in Delphi 11-CodePudding

In Delphi 10.4, I was able to get a listing of files in an Android device's shared storage. In Delphi 11, with necessary permission set (either programmatically or on the device), TDirectory.GetFiles() is returning an empty list (ie. zero entries).

TDirectory.GetDirectories() is working correctly, and using TFile.Exists() with a filename which I know to be present returns true. But, if I try to open that file with, for instance, TFile.ReadAllText(), access is denied. Any suggestions?

This is an example program which fails in Delphi 11:

uses
  System.Types,System.Classes,system.sysUtils,system.IOUtils,system.Permissions,
 {$IFDEF ANDROID}
   Androidapi.Helpers,
   Androidapi.JNI.JavaTypes,
   Androidapi.JNI.Os,
 {$ENDIF}
  FMX.Types,FMX.Forms,FMX.Dialogs;

type
  TForm1 = class(TForm)
   procedure FormCreate(Sender: TObject);
  private
   fOK:boolean;
   procedure PermissionsResult(Sender: TObject;
      const APermissions: TClassicStringDynArray;
      const AGrantResults: TClassicPermissionStatusDynArray);
  end;

var
  Form1: TForm1;

implementation
{$R *.fmx}

procedure Tform1.PermissionsResult(Sender: TObject;
  const APermissions: TClassicStringDynArray;
  const AGrantResults: TClassicPermissionStatusDynArray);
 var
  n:integer;
 begin
  if length(AGrantResults)>0 then
   for n:=0 to length(AGrantResults)-1 do
    if not (AGrantResults[n] = TPermissionStatus.Granted) then fOK:=false;
 end;

procedure FileList(dir:string;list:TstringList);
 var
  LList: TStringDynArray;
  I: Integer;
 begin
  list.Clear;
  Llist:=Tdirectory.GetFiles(dir);
  if length(LList)>0 then
   for I := 0 to Length(LList) - 1 do
    list.Add(LList[I]);
 end;

procedure TForm1.FormCreate(Sender: TObject);
 var
  DataDir:string;
  list:TstringList;
  p:Tarray<string>;
 begin
  fOK:=true;
  p:=[JStringToString(TJManifest_permission.JavaClass.READ_EXTERNAL_STORAGE),
        JStringToString(TJManifest_permission.JavaClass.WRITE_EXTERNAL_STORAGE)];
  PermissionsService.RequestPermissions(p,PermissionsResult,nil);
  if fOK then
   begin
    list:=TstringList.Create;
    DataDir := TPath.GetSharedDocumentsPath;
showmessage(DataDir);
    fileList(DataDir,list);
showmessage(inttostr(list.Count) ' ' list.Text);
    list.Free;
   end else showmessage('permission refused');
 end;

end.

CodePudding user response：

On an Android 11 devices listFiles() will, depending on the exact public directory, list only files created by the app itself or some media files.

Do not only use TFile.Exists() but also TFile.CanRead() before you try to .. read.

CodePudding user response：

This will list files:

var
  FileList: TStringDynArray;
  myfileList: Tstringlist;
  s: string;
  DocDir: string; 
begin
  DocDir := TPath.GetSharedDocumentsPath;// or whatever path
  FileList := TDirectory.GetFiles(DocDir);
  myfileList := TStringList.Create;

  for s in FileList do begin //get all items in folder
    if Pos('.png',s) > 0 then begin
      try  
        myfileList.Add(s);             
      except
        //
      end;  
    end;
  end;
  myfileList.Free;  
end;