Vcl.Forms.TCustomForm.OnClose
Delphi
property OnClose: TCloseEvent read FOnClose write FOnClose stored IsForm;
C++
__property TCloseEvent OnClose = {read=FOnClose, write=FOnClose, stored=IsForm};
Properties
| Type | Visibility | Source | Unit | Parent |
|---|---|---|---|---|
| event | protected | Vcl.Forms.pas Vcl.Forms.hpp |
Vcl.Forms | TCustomForm |
Description
Occurs when the form closes.
Use OnClose to perform special processing when the form closes. The OnClose event specifies which event handler to call when a form is about to close. The handler specified by OnClose might, for example, test to make sure all fields in a data-entry form have valid contents before allowing the form to close.
A form is closed by the Close method or when the user chooses Close from the form's system menu.
The TCloseEvent type points to a method that handles the closing of a form. The value of the Action parameter determines if the form actually closes. These are the possible values of Action:
| Value | Meaning |
|---|---|
|
caNone |
The form is not allowed to close, so nothing happens. |
|
caHide |
The form is not closed, but just hidden. Your application can still access a hidden form. |
|
caFree |
The form is closed and all allocated memory for the form is freed. |
|
caMinimize |
The form is minimized, rather than closed. This is the default action for MDI child forms. |
If a form is an MDI child form, and its BorderIcons property is biMinimize, then the default Action is caMinimize. If a MDI child form does not have these settings, the default Action is caNone, meaning that nothing happens when the user attempts to close the form.
If a form is an SDI child form, Action defaults to caHide.
To close the form and free it in an OnClose event, set Action to caFree.
Note: When the application shuts down, the main form receives an OnClose event, but any child forms do not receive the OnClose event.
See Also
Code Examples