TApplication

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Revision as of 22:47, 19 November 2020 by Arent (talk | contribs) (Events)

TApplication (with instance Application) that is available in every Lazarus program.

Unlike forms, and components on the forms a (single) instance of TApplication is created before any user line of code. In a .lpr file (a pascal file containing the keyword 'program' ) the Application-variable is used to create the applications form(s):

program pMyTest;
uses
  Forms, uMyForm

{$R *.res}

begin
  Application.Initialize();
  Application.CreateForm( TMyForm, MyForm );
  Application.Run();
end.

TMyForm is assumed a descendant of TForm and defined in uMyForm.pas

Properties

Properties
Property type Writable Description
ExeName string - Name of the executable.
HelpFile string rw Location of the application help file.
Terminated Boolean - Was Terminate called or not
Title string rw Application title
ConsoleApplication Boolean - Is the application a console application or not
Location string - Application location
Params[] string - Command-line parameters
ParamCount Integer - Number of command-line parameters
EnvironmentVariable[] string - Environment variable access
OptionChar Char rw Command-line switch character
CaseSensitiveOptions Boolean rw Are options interpreted case sensitive or not
StopOnException Boolean rw Should the program loop stop on an exception
ExceptionExitCode LongInt rw ExitCode to use then terminating the program due to an exception
EventLogFilter TEventLogTypes rw Event to filter events, before they are sent to the system log
SingleInstance TBaseSingleInstance - Single instance used to control single application instance behaviour
SingleInstanceClass TBaseSingleInstanceClass rw Class to use when creating single instance
SingleInstanceEnabled Boolean rw Enable single application instance control.
Active Boolean True if the application has the focus.
ApplicationType TApplicationType rw The type of the application (i.e. the sort of device for which it is intended).
BidiMode TBiDiMode rw The bidirectional mode to use.
CaptureExceptions Boolean rw Enables exception handling by Application.
DoubleBuffered TApplicationDoubleBuffered rw platform
ExtendedKeysSupport Boolean rw
ExceptionDialog TApplicationExceptionDlg rw
FindGlobalComponentEnabled Boolean rw Enables searching for global components by name.
Flags TApplicationFlags rw Application state flags.
Handle THandle rw platform ;
Hint string rw The current Hint text.
HintColor TColor rw The color of Hint windows.
HintHidePause Integer rw How long a Hint stays visible, after an mouse move.
HintHidePausePerChar Integer rw How much a keystroke extends the time a Hint stays visible (added to HintHidePause).
HintPause Integer rw The delay before a Hint is shown.
HintShortCuts Boolean rw Enables the display of keyboard shortcuts (e.g. on menu entries).
HintShortPause Integer rw The pause before a different Hint is displayed.
Icon TIcon rw The icon associated with this application.
LayoutAdjustmentPolicy TLayoutAdjustmentPolicy rw
Navigation TApplicationNavigationOptions rw Allows to switch between controls by pressing keys.
MainForm TForm The application terminates when this form is closed.
MainFormHandle HWND the Handle of the MainForm
MainFormOnTaskBar Boolean rw platform
ModalLevel Integer The number of modal forms shown.
MoveFormFocusToChildren Boolean rw
MouseControl TControl The control currently under the mouse.
TaskBarBehavior TTaskBarBehavior rw How forms are represented in the TaskBar.
UpdateFormatSettings Boolean rw platform;
Scaled Boolean rw

Events

Events
Event type Description
OnException TExceptionEvent Exception handling event
OnActionExecute TActionEvent Default handler for unhandled Actions
OnActionUpdate TActionEvent Default handler for unhandled Action updates
OnActivate TNotifyEvent activation of the application.
OnDeactivate TNotifyEvent deactivation of the application.
OnGetMainFormHandle TGetHandleEvent
OnIdle TIdleEvent for application entering Idle state.
OnIdleEnd TNotifyEvent for application leaving Idle state.
OnEndSession TNotifyEvent for ending a session of the application
OnQueryEndSession TQueryEndSessionEvent can deny to end the session.
OnMinimize TNotifyEvent for application minimized.
OnMessageDialogFinished TModalDialogFinished
OnModalBegin TNotifyEvent for a modal form opened (application entering modal mode).
OnModalEnd TNotifyEvent all modal forms closed (application exiting modal mode).
OnRestore TNotifyEvent for application restored (from minimized/maximized state).
OnDropFiles TDropFilesEvent The default handler for dropped files
OnHelp THelpEvent when help is requested.
OnHint TNotifyEvent when a hint is requested.
OnShortcut TShortCutEvent interpret keystrokes as shortcuts, before the normal target handles the key.
OnShowHint TShowHintEvent showing a Hint.
OnUserInput TOnUserInputEvent
OnDestroy TNotifyEvent rw
OnCircularException TExceptionEvent Handler invoked when there is an exception circle before killing the app with Halt
ShowButtonGlyphs TApplicationShowGlyphs Allows to override the platform default for glyphs on buttons.
ShowMenuGlyphs TApplicationShowGlyphs Sets the default policy for showing or hiding glyph images in menus
ShowHint Boolean Enables Hint display
ShowMainForm Boolean Allows to show or hide the main form, on application start. Default TRUE.

see also