我希望创建一个像“TOwnedStringList”(类名是一个小说),我可以构造为：
sl := TOwnedStringList.Create(Self); sl.Sorted := True; sl.Duplicates := dupIgnore; sl.Add(...); // etc...
其中Self可以是一个Form(例如),所以所有者将自动释放StringList.
我想要能够避免自己调用sl.Free.
这可能吗？
解决方法
那会有点混乱你需要做这样的事情.
type
TOwnerComponent = class(TComponent)
private
FOwnedObject: TObject;
public
constructor Create(Owner: TComponent; OwnedObject: TObject);
destructor Destroy; override;
end;
TOwnedStringList = class(TStringList)
private
FOwner: TOwnerComponent;
public
constructor Create(Owner: TComponent);
destructor Destroy; override;
end;
{ TOwnerComponent }
constructor TOwnerComponent.Create(Owner: TComponent; OwnedObject: TObject);
begin
inherited Create(Owner);
FOwnedObject := OwnedObject;
end;
destructor TOwnerComponent.Destroy;
begin
FOwnedObject.Free;
inherited;
end;
{ TOwnedStringList }
constructor TOwnedStringList.Create(Owner: TComponent);
begin
inherited Create;
if Assigned(Owner) then
FOwner := TOwnerComponent.Create(Owner,Self);
end;
destructor TOwnedStringList.Destroy;
begin
if Assigned(FOwner) and not (csDestroying in FOwner.ComponentState) then
begin
FOwner.FOwnedObject := nil;
FOwner.Free;
end;
inherited;
end;
基本上,您创建一个由owner所拥有的TOwnerComponent的实例,该实例将传递给TOwnedStringList.Create.当该拥有者去世时,它会破坏TOwnerComponent,这又破坏了你的字符串列表.