这是我的代码示例: type TMyBaseClass = class public procedure SomeProc; virtual; end; TMyChildClass = class(TMyBaseClass) public procedure SomeProc; override; end;var SomeDelegate: procedure of object;procedure TMyBaseClass.SomePro
type
TMyBaseClass = class
public
procedure SomeProc; virtual;
end;
TMyChildClass = class(TMyBaseClass)
public
procedure SomeProc; override;
end;
var
SomeDelegate: procedure of object;
procedure TMyBaseClass.SomeProc;
begin
ShowMessage('Base proc');
end;
procedure TMyChildClass.SomeProc;
begin
ShowMessage('Child proc');
// here i want to get a pointer to TMyBaseClass.SomeProc (NOT IN THIS CLASS!):
SomeDelegate := SomeProc;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
with TMyChildClass.Create do
try
// there will be "Child proc" message:
SomeProc;
finally
Free;
end;
// there i want to get "Base proc" message, but i get "Child proc" again
// (but it is destroyed anyway, how coud it be?):
SomeDelegate;
end;
我知道的一种方式是:
procedure TMyChildClass.BaseSomeProc;
begin
inherited SomeProc;
end;
procedure TMyChildClass.SomeProc;
begin
ShowMessage('Child proc');
SomeDelegate := BaseSomeProc;
end;
第二个是将SomeProc声明从覆盖更改为重新引入:
TMyChildClass = class(TMyBaseClass)
public
procedure SomeProc; reintroduce;
end;
然后将self转换为TMyBaseClass(不要使用as cast):
SomeDelegate := TMyBaseClass(self).SomeProc;
另请注意,您的代码将提供访问冲突,因为您在已释放的对象上调用SomeDelegate.
