How can read in pictures and view them using a button Delphi - delphi

Question

I know how to load and view one picture in delphi. However I would like to add a 'next image' button that brings up the next image in the file. I have 5 images in a file and i would like to scroll through them easily using a next button! I have tried to make the next button, But have no idea what code to put in!
Please help thanks.
Gpath is a global string variable.
procedure TPropertyForm.FormCreate(Sender: TObject);
begin
GPath := getcurrentdir + '\EmployeePhotos\';
EmployeeOpenPictureDialog.InitialDir := getcurrentdir + '\EmployeePhotos';
end;
procedure TPropertyForm.AttatchButtonClick(Sender: TObject);
var
st: string;
fsize, psize: integer;
begin
if EmployeeOpenPictureDialog.execute then
begin
st := EmployeeOpenPictureDialog.FileName;
psize := length(GPath);
fsize := length(st);
Properties.Photo := copy(st, psize + +1, fsize - psize)
end { endif };
PhotoImage.Hide;
if Properties.Photo <> '' then
begin
st := GPath + Properties.Photo;
if FileExists(st) then
begin
PhotoImage.Picture.LoadFromFile(st);
PhotoImage.Proportional := true;
PhotoImage.Show;
end
{ endif }
end; { endif }
end
procedure TPropertyForm.NextImageButtonClick(Sender: TObject);
begin
PhotoImage.Picture.LoadFromFile(st + 1);
end;

Answer 1

i think you want to load images from "Folder" and switch between them, if so try this code
place 2 TButtons and 1 TImage
uses jpeg;
public
{ Public declarations }
var
SL:TStringList;
ImgIndex:integer;
GPath:String;
procedure ListFileDir(Path: string; FileList: TStrings);
var
SR: TSearchRec;
begin
if FindFirst(Path + '*.jpg', faAnyFile, SR) = 0 then
begin
repeat
if (SR.Attr <> faDirectory) then
begin
FileList.Add(SR.Name);
end;
until FindNext(SR) <> 0;
FindClose(SR);
end;
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
GPath:= getcurrentdir + '\EmployeePhotos\';
SL:=TStringList.Create;
ListFileDir(GPath,SL);
Image1.Picture.LoadFromFile(GPath + SL.Strings[ImgIndex] );
end;
procedure TForm1.btnNextClick(Sender: TObject);
begin
ImgIndex:=ImgIndex+1;
if ImgIndex=SL.Count then ImgIndex :=0;
Image1.Picture.LoadFromFile(GPath + SL.Strings[ImgIndex] );
end;
procedure TForm1.btnPrevClick(Sender: TObject);
begin
ImgIndex:=ImgIndex-1;
if ImgIndex=-1 then ImgIndex :=SL.Count-1;
Image1.Picture.LoadFromFile(GPath + SL.Strings[ImgIndex] );
end;
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
SL.Free;
end;