我在学习《Delphi5从入门到精通》,作者说“在处理对象某个时间的同时,不能
消除该对象,否则会引起一个异常”,可我在窗体中建立一个按纽,处理OnClick
事件时:
procedure TForm1.ButtonKeyPress(Sender:TObject,var Key:Char)
begin
if Key=#8 then
Sender.Free;
end;
未出现任何问题,难道Marco Cantu写错了吗?请大侠指点
...全文
14019打赏收藏
难道Marco Cantu写错了吗
我在学习《Delphi5从入门到精通》,作者说“在处理对象某个时间的同时,不能 消除该对象,否则会引起一个异常”,可我在窗体中建立一个按纽,处理OnClick 事件时: procedure TForm1.ButtonKeyPress(Sender:TObject,var Key:Char) begin if Key=#8 then Sender.Free; end; 未出现任何问题,难道Marco Cantu写错了吗?请大侠指点
Destroys an object and frees its associated memory, if necessary.
procedure Free;
Description
Use Free to destroy an object. Free automatically calls the destructor if the object reference is not nil
. Any object instantiated at runtime that does not have an Owner should be destroyed by a call to Free, so that can be properly destroyed and the memory released. Unlike Destroy, Free is successful even if the object is nil, so if the object was never initialized, Free won抰 result in an error.
When you call Free for a component, it calls Free for all components that it owns, that is, all components in its component list. A form owns all the controls and non-visual components that are created on it in design mode. When it is freed, all of these components are automatically freed as well. Since, by default, all forms are owned by the Application object, when the application terminates, it frees the Application object, which frees all forms. For all objects that are not components, or for components created with a nil owner, be sure to call Free after you are finished with the object; otherwise the allocated memory will not be usable until after the application terminates.
Warning: Never explicitly free a component within one of its own event
handlers or free a component from the event handler of a
component it owns or contains. For example, don抰 free a button
in its OnClick event handler or free the form that owns the
button from the button's OnClick event.
To free a form, call its Release method, which destroys the form and releases the memory allocated for it after all its event handlers and those of the components it contains are through executing.