TAction

From Lazarus wiki
Jump to: navigation, search

English (en) español (es)

A TAction object is a container for specific action-related topics like events, description, help-topic, icon, shortcut(s). When using TActions in the Action-property of buttons, menus, dialogs, controls it is possible to centralize the effects of mouse-clicks, menu-choices, dialog-selections, shortcuts etc. in a single event handler.

Example

We want to have a TAction that handles opening of some other form. Make sure to have a TActionList on the main form. Doubleclick the TActionList to get the ActionList Editor. Create a new action by hitting the plus-sign. In the Object Inspector, set the name to actSomeAction, set a desired shortcut, a caption to be uses in menu's, an imageindex if a TImageList is connected to the parent ActionList, Hint is hints are to be displayed, helpkeyword and other properties where relevant.

The most important is the OnExecute-event that will be executed if the action is triggered somehow (menu, shortcut, button).

procedure TMyForm.actSomeActionExecute(Sender: TObject);
var
  f: TSomeForm;
  rv: integer;
begin
  f := TSomeForm.Create( nil );
  f.Caption := 'SomeForm';
  rv := f.ShowModal();
  if rv=mrOk then
    DoSomethingMeaningful();  
  f.Free();
end;

If you use the newly created action in a TMenuItem of a TMainMenu or TPopupMenu you are ready to go.

See also