Question

I am a Delphi learner. I am looking for solutions so that Delphi MainForm should be minimized to the System Tray instead of Taskbar using Timer. I have implemented the following codes. Here everything is fine except one. After minimizing the Form, it goes to “SystemTray” but also available in “TaskBar. For my application, the “AlphaBlend” property of “Form001” is true and “AlphaBlendValue” is “0”.

unit KoushikHalder001;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Vcl.Buttons, Vcl.ExtCtrls, Vcl.Imaging.pngimage,
  Vcl.AppEvnts, Vcl.ImgList, Vcl.Menus;

type
  TForm001 = class(TForm)
    Edit001: TEdit;
    Background: TImage;
    BitBtn001: TBitBtn;
    BitBtn002: TBitBtn;
    FadeInTimer: TTimer;
    FadeOutTimer: TTimer;
    FormMinimizeTimer: TTimer;
    FormRestoreTimer: TTimer;
    TrayIcon: TTrayIcon;
    PopupMenu: TPopupMenu;
    ImageList: TImageList;
    ApplicationEvents: TApplicationEvents;
    Form001Close: TMenuItem;
    Form001Hide: TMenuItem;
    Form001Show: TMenuItem;
    Form002Close: TMenuItem;
    Form002Hide: TMenuItem;
    Form002Show: TMenuItem;
    N01: TMenuItem;
    N02: TMenuItem;
    N03: TMenuItem;
    N04: TMenuItem;
    N05: TMenuItem;
    N06: TMenuItem;
    N07: TMenuItem;
    N08: TMenuItem;
    N09: TMenuItem;
    N10: TMenuItem;
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure FormHide(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure BitBtn001Click(Sender: TObject);
    procedure BitBtn002Click(Sender: TObject);
    procedure FadeInTimerTimer(Sender: TObject);
    procedure FadeOutTimerTimer(Sender: TObject);
    procedure FormMinimizeTimerTimer(Sender: TObject);
    procedure FormRestoreTimerTimer(Sender: TObject);
    procedure ApplicationEventsMinimize(Sender: TObject);
    procedure TrayIconDblClick(Sender: TObject);
    procedure Form001CloseClick(Sender: TObject);
    procedure Form001HideClick(Sender: TObject);
    procedure Form001ShowClick(Sender: TObject);
    procedure Form002CloseClick(Sender: TObject);
    procedure Form002HideClick(Sender: TObject);
    procedure Form002ShowClick(Sender: TObject);
  private
    { Private declarations }
    CrossButtonClick: Boolean;
    procedure WMNCHitTest(var Msg: TWMNCHitTest) ; message WM_NCHitTest;
    procedure WMSysCommand(var Msg: TWMSysCommand) ; message WM_SysCommand;
  public
    { Public declarations }
  end;

var
  Form001: TForm001;

implementation

{$R *.dfm}

uses KoushikHalder002;

procedure TForm001.WMNCHitTest(var Msg: TWMNCHitTest);
begin
  inherited;
  if ControlAtPos(ScreenToClient(Msg.Pos), True, True, True)= nil
    then
      begin
        if Msg.Result=htClient then Msg.Result := htCaption;
      end;
end;

procedure TForm001.WMSysCommand(var Msg: TWMSysCommand);
begin
  case Msg.CmdType of
    SC_MINIMIZE:
      begin
        if Form001.AlphaBlendValue > 0 then
          begin
            Form001.FormMinimizeTimer.Enabled := true;
            Exit;
          end;
      end;
    SC_RESTORE:
      begin
        if Form001.AlphaBlendValue < 220 then
          begin
            Form001.FormRestoreTimer.Enabled := True;
          end;
      end;
  end;
  inherited;
end;

procedure TForm001.ApplicationEventsMinimize(Sender: TObject);
begin
  Form001.FormMinimizeTimer.Enabled := true;
  TrayIcon.Visible := True;
  TrayIcon.Animate := True;
  TrayIcon.ShowBalloonHint;
end;

procedure TForm001.BitBtn001Click(Sender: TObject);
begin
  if Form002.WindowState = wsMinimized then
    begin
      Form002.Perform(WM_SYSCOMMAND, SC_RESTORE, 0);
    end
    else
    Form002.show;
end;

procedure TForm001.BitBtn002Click(Sender: TObject);
begin
  Form002.FadeOutTimer.Enabled := true;
  Form001.FadeOutTimer.Enabled := true;
end;

procedure TForm001.Form001CloseClick(Sender: TObject);
begin
  Form002.FadeOutTimer.Enabled := true;
  Form001.FadeOutTimer.Enabled := true;
end;

procedure TForm001.Form001HideClick(Sender: TObject);
begin
Form001.FormMinimizeTimer.Enabled := true;
end;

procedure TForm001.Form001ShowClick(Sender: TObject);
begin
  if Form001.WindowState = wsMinimized then
    begin
      Form001.Perform(WM_SYSCOMMAND, SC_RESTORE, 0);
    end
    else
    Form001.show;
end;

procedure TForm001.Form002CloseClick(Sender: TObject);
begin
Form002.FadeOutTimer.Enabled := true;
end;

procedure TForm001.Form002HideClick(Sender: TObject);
begin
Form002.FormMinimizeTimer.Enabled := true;
end;

procedure TForm001.Form002ShowClick(Sender: TObject);
begin
  if Form002.WindowState = wsMinimized then
    begin
      Form002.Perform(WM_SYSCOMMAND, SC_RESTORE, 0);
    end
    else
    Form002.show;
end;

procedure TForm001.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Form001.FadeOutTimer.Enabled := true;
end;

procedure TForm001.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
  if CrossButtonClick = true
    then
      begin
        CanClose := true;
        Exit;
      end;
  CanClose := false;
  Form001.FadeOutTimer.Enabled := true;
end;

procedure TForm001.FormHide(Sender: TObject);
begin
  Form001.FadeOutTimer.Enabled := true;
end;

procedure TForm001.FormShow(Sender: TObject);
begin
  Form001.FadeInTimer.Enabled := true;
end;
procedure TForm001.TrayIconDblClick(Sender: TObject);
begin
  Form001.FormRestoreTimer.Enabled := true;
  TrayIcon.Visible := False;
  WindowState := wsNormal;
  Application.BringToFront();
end;

procedure TForm001.FadeInTimerTimer(Sender: TObject);
begin
  if Form001.AlphaBlendValue >= 220
    then
      begin
        Form001.FadeInTimer.Enabled := false;
      end
    else
      begin
        Form001.AlphaBlendValue := Form001.AlphaBlendValue + 10;
        CrossButtonClick := false;
      end;
end;

procedure TForm001.FadeOutTimerTimer(Sender: TObject);
begin
  if Form001.AlphaBlendValue <= 0
    then
      begin
        Form001.FadeOutTimer.Enabled := false;
        CrossButtonClick := true;
        Self.Close;
      end
    else
      begin
        Form001.AlphaBlendValue := Form001.AlphaBlendValue - 10;
        CrossButtonClick := true;
      end;
end;

procedure TForm001.FormMinimizeTimerTimer(Sender: TObject);
begin
  if Form001.AlphaBlendValue > 0 then
    begin
      Form001.AlphaBlendValue := Form001.AlphaBlendValue - 10;
    end
  else
    begin
      Form001.FormMinimizeTimer.Enabled := false;
      Perform(WM_SYSCOMMAND, SC_MINIMIZE, 0);
    end;
end;

procedure TForm001.FormRestoreTimerTimer(Sender: TObject);
begin
  if Form001.AlphaBlendValue < 220 then
    begin
      Form001.AlphaBlendValue := Form001.AlphaBlendValue + 10;
    end
  else
    begin
      Form001.FormRestoreTimer.Enabled := false;
    end;
end;

end.

If I do the following

Application.MainFormOnTaskbar := false;

when the application runs the form is totally invissible. I think there should be one bug. But I am unable to find it. Please help me.

Answer 1

You should HIDE application. Here is a procedure to Hide and Restore application from TaskBar and Desktop. If you have more than one form visible in your Application uncomment Application.Minimize and Application.Restore:

procedure TMainForm.ChangeApplicationVisibility;
begin
    if Visible then
      begin
       Hide;
//       Application.Minimize;
       ShowWindow(Application.Handle,SW_Hide);
      end
    else
    begin
     Show;
//     Application.Restore;
     Application.BringToFront;
    end;
end;