CustomPage for Serial Number in Inno Setup

You can make Inno prompt the user for a serial key by adding an CheckSerial() event function.

If you want more control over the page, you can use one of the stock pages (CreateInput...Page) or a custom page in the setup wizard using CreateCustomPage() and adding controls as you require.

See the codedlg.iss example included with Inno setup.

Here is one approach that uses the custom page where the separate edit boxes are created. You only need to specify the value for the SC_EDITCOUNT constant where the number of edit boxes is defined and the SC_CHARCOUNT what is the number of characters that can be entered into these edit boxes. If you are in the first edit box you may paste the whole serial number if it's in the format by the pattern delimited by the - char (the TryPasteSerialNumber function here). To get the serial number from the edit boxes it's enough to call GetSerialNumber where you can specify also a delimiter for the output format (if needed).

[Setup]
AppName=Serial number project
AppVersion=1.0
DefaultDirName={pf}\Serial number project

[code]
function SetFocus(hWnd: HWND): HWND;
  external '[email protected] stdcall';
function OpenClipboard(hWndNewOwner: HWND): BOOL;
  external '[email protected] stdcall';
function GetClipboardData(uFormat: UINT): THandle;
  external '[email protected] stdcall';
function CloseClipboard: BOOL;
  external '[email protected] stdcall';
function GlobalLock(hMem: THandle): PAnsiChar;
  external '[email protected] stdcall';
function GlobalUnlock(hMem: THandle): BOOL;
  external '[email protected] stdcall';

var
  SerialPage: TWizardPage;
  SerialEdits: array of TEdit;

const
  CF_TEXT = 1;
  VK_BACK = 8;
  SC_EDITCOUNT = 6;
  SC_CHARCOUNT = 5;
  SC_DELIMITER = '-';

function IsValidInput: Boolean;
var
  I: Integer;
begin
  Result := True;
  for I := 0 to GetArrayLength(SerialEdits) - 1 do
    if Length(SerialEdits[I].Text) < SC_CHARCOUNT then
    begin
      Result := False;
      Break;
    end;
end;

function GetClipboardText: string;
var
  Data: THandle;
begin
  Result := '';
  if OpenClipboard(0) then
  try
    Data := GetClipboardData(CF_TEXT);
    if Data <> 0 then
      Result := String(GlobalLock(Data));
  finally
    if Data <> 0 then
      GlobalUnlock(Data);
    CloseClipboard;
  end;
end;

function GetSerialNumber(ADelimiter: Char): string;
var
  I: Integer;
begin
  Result := '';
  for I := 0 to GetArrayLength(SerialEdits) - 1 do
    Result := Result + SerialEdits[I].Text + ADelimiter;
  Delete(Result, Length(Result), 1);
end;

function TrySetSerialNumber(const ASerialNumber: string; ADelimiter: Char): Boolean;
var
  I: Integer;
  J: Integer;
begin
  Result := False;

  if Length(ASerialNumber) = ((SC_EDITCOUNT * SC_CHARCOUNT) + (SC_EDITCOUNT - 1)) then
  begin
    for I := 1 to SC_EDITCOUNT - 1 do
      if ASerialNumber[(I * SC_CHARCOUNT) + I] <> ADelimiter then
        Exit;

    for I := 0 to GetArrayLength(SerialEdits) - 1 do
    begin
      J := (I * SC_CHARCOUNT) + I + 1;
      SerialEdits[I].Text := Copy(ASerialNumber, J, SC_CHARCOUNT);
    end;

    Result := True;
  end;
end;

function TryPasteSerialNumber: Boolean;
begin
  Result := TrySetSerialNumber(GetClipboardText, SC_DELIMITER);
end;

procedure OnSerialEditChange(Sender: TObject);
begin
  WizardForm.NextButton.Enabled := IsValidInput;
end;

procedure OnSerialEditKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
var
  Edit: TEdit;
  EditIndex: Integer;
begin
  Edit := TEdit(Sender);
  EditIndex := Edit.TabOrder - SerialEdits[0].TabOrder;
  if (EditIndex = 0) and (Key = Ord('V')) and (Shift = [ssCtrl]) then
  begin
    if TryPasteSerialNumber then
      Key := 0;
  end
  else
  if (Key >= 32) and (Key <= 255) then
  begin
    if Length(Edit.Text) = SC_CHARCOUNT - 1 then
    begin
      if EditIndex < GetArrayLength(SerialEdits) - 1 then
        SetFocus(SerialEdits[EditIndex + 1].Handle)
      else
        SetFocus(WizardForm.NextButton.Handle);
    end;
  end
  else
  if Key = VK_BACK then
    if (EditIndex > 0) and (Edit.Text = '') and (Edit.SelStart = 0) then
      SetFocus(SerialEdits[EditIndex - 1].Handle);
end;

procedure CreateSerialNumberPage;
var
  I: Integer;
  Edit: TEdit;
  DescLabel: TLabel;
  EditWidth: Integer;
begin
  SerialPage := CreateCustomPage(wpWelcome, 'Serial number validation',
    'Enter the valid serial number');

  DescLabel := TLabel.Create(SerialPage);
  DescLabel.Top := 16;
  DescLabel.Left := 0;
  DescLabel.Parent := SerialPage.Surface;
  DescLabel.Caption := 'Enter valid serial number and continue the installation...';
  DescLabel.Font.Style := [fsBold];

  SetArrayLength(SerialEdits, SC_EDITCOUNT);
  EditWidth := (SerialPage.SurfaceWidth - ((SC_EDITCOUNT - 1) * 8)) div SC_EDITCOUNT;

  for I := 0 to SC_EDITCOUNT - 1 do
  begin
    Edit := TEdit.Create(SerialPage);
    Edit.Top := 40;
    Edit.Left := I * (EditWidth + 8);
    Edit.Width := EditWidth;
    Edit.CharCase := ecUpperCase;
    Edit.MaxLength := SC_CHARCOUNT;
    Edit.Parent := SerialPage.Surface;
    Edit.OnChange := @OnSerialEditChange;
    Edit.OnKeyDown := @OnSerialEditKeyDown;
    SerialEdits[I] := Edit;
  end;
end;

procedure CurPageChanged(CurPageID: Integer);
begin
  if CurPageID = SerialPage.ID then
    WizardForm.NextButton.Enabled := IsValidInput;  
end;

procedure InitializeWizard;
begin
  CreateSerialNumberPage;
end;

And here is how it looks like: