Re: TZF - seeking in a VirtualFile

Hi, I'll send you a small program which make use of  seek & peek in a
TzVFile.

The code is something like this one:

procedure TForm1.Btn1Click(Sender: TObject);
 var s: String;
Begin
 s := LPad (SysUtils.Trim (ed.Text), 4);
 with Vf do
 if (s <> '') and (Active) then
 begin
  GoTop;
  while not dEof do
  begin
   if GetField ('REF') = s then
    Break;
   Skip (1);
  end;
  if dEof then
   Lbl.Caption := 'NO !'
  else
   Lbl.Caption := 'YES !';
 end;
End;

procedure TForm1.Btn2Click(Sender: TObject);
 var s: String;
     n, MaxRec: LongInt;
     Ok: Boolean;
Begin
 Ok := False;
 s := LPad (SysUtils.Trim (ed.Text), 4);
 with Vf do
 if (s <> '') and (Active) then
 begin  // no need for "GOTOP"
  MaxRec := RecCount;
  for n := 1 to MaxRec do
   if Peek (1, n) = s then
   begin
    Go (n);
    Ok := True;
    Break;
   end;
  if Ok then
   Lbl.Caption := 'YES !'
  else
   Lbl.Caption := 'NO !';
 end;
End;

procedure TForm1.Btn3Click(Sender: TObject);
 var s: String;
Begin
 s := Pad (Upper (SysUtils.Trim (ed.Text)), 30);
 with Vf do
 if (s <> '') and (Active) then
 begin
  GoTop;
  while not dEof do
  begin
   if Upper (GetField ('NAME')) = s then
    Break;
   Skip (1);
  end;
  if dEof then
   Lbl.Caption := 'NO !'
  else
   Lbl.Caption := 'YES !';
 end;
End;

procedure TForm1.Btn4Click(Sender: TObject);
 var s: String;
     n, MaxRec: LongInt;
     Ok: Boolean;
Begin
 Ok := False;
 s := Pad (Upper (SysUtils.Trim (ed.Text)), 30);
 with Vf do
 if (s <> '') and (Active) then
 begin // no need for "GOTOP"
  MaxRec := RecCount;
  for n := 1 to MaxRec do
  begin
   if Upper (Peek (2, n)) = s then
   begin
    Go (n);
    Ok := True;
    Break;
   end;
  end;
  if Ok then
   Lbl.Caption := 'YES !'
  else
   Lbl.Caption := 'NO !';
 end;
End;

Btn1 & Btn2 seek on a numeric field and Btn3 & 4 seek on a character field.

Gerard.

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