Agfdhyk

I have a program which allows the user to click on a directory and the program will start loading all the images there and shows them on the screen and the user can view them by scrolling down

Now here is the issue, after the program loads a directory, if the user clicks on another directory, after loading the new directory some times there are remains of the previous images on the screen (Form) !, now here is the thing, if i for example try focusing another controller(component) and then i click on the form, the remains will get cleaned! so it seems the problem lies with the fact the form is not repainted or something like that!

Here is what you need to know about my program :

1-What i said happens in Fullscreen
2-I am in FMX and i use TImage

In the end i should mention that i have already tried using form1.invalidate;, which cleans the remains of something like an image resize but doesn't work on the image remains (when i say remains i mean a whole picture not residues)

Update 01:

Honestly it was fairly hard to reproduce this problem, i tried my best and i think this example kinda shows what i am talking about, i think the issue arises from the fact that i am doing my loading and cleaning in another thread, because i was not able to reproduce this problem in a single thread application

Here is the test case code:

unit Unit2;



interface



uses

  System.SysUtils, System.Types, System.UITypes, System.Classes, System.Variants,

  FMX.Types, FMX.Controls, FMX.Forms, FMX.Graphics, FMX.Dialogs,

  FMX.Controls.Presentation, FMX.StdCtrls, System.Generics.Collections,

  FMX.Objects;



type

  TForm2 = class(TForm)

    Timer1: TTimer;

    procedure FormCreate(Sender: TObject);

    procedure Timer1Timer(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;



var

  Form2: TForm2;

  mImageList: TList<TImage>;

  mSwitch: boolean;



implementation

uses

  Threading;



{$R *.fmx}



procedure TForm2.FormCreate(Sender: TObject);

var

  cImage: TImage;

  I: Integer;

begin

  mImageList := TList<TImage>.create;

  mSwitch := false;



  for I := 0 to 3 do

  begin

    cImage := TImage.Create(nil);

    cImage.Parent := Form2;

    mImageList.Add(cImage);

  end;



  Form2.FullScreen := true;

  timer1.Interval := 3000;

end;



procedure TForm2.Timer1Timer(Sender: TObject);



begin



  TThread.CreateAnonymousThread(procedure

    var

      I: Integer;

      heightSum: single;

      path: string;

    begin

      if not(mSwitch) then

        path := 'images11 ('

      else

        path := 'images22 (';



      heightSum := 0;



      for I := 0 to mImageList.Count - 1 do

      begin

        mImageList[I].Bitmap := nil;

      end;



      for I := 0 to mImageList.Count - 1 do

      begin

        mImageList[I].Bitmap.LoadFromFile(path + (i + 1).ToString + ').jpg');

        mImageList[I].Width := mImageList[I].Bitmap.Width;

        mImageList[I].Height := mImageList[I].Bitmap.Height;

        mImageList[I].Position.X := Form2.Width / 2 - mImageList[I].Width / 2;

        mImageList[I].Position.Y := heightSum;

        heightSum := heightSum + mImageList[I].Height;

      end;



      TThread.Synchronize(nil, procedure

        begin

        end);

    end).Start;





  mSwitch := not(mSwitch);

end;



end.