摘要： 测试效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ComCtrls, ExtCtrls; type TForm1 = class(TForm) TreeView1... 阅读全文

摘要： 本例效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ComCtrls; type TForm1 = class(TForm) TreeView1: TTreeVie... 阅读全文

摘要： 本例效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ImgList, ComCtrls; type TForm1 = class(TForm) TreeView1: TTreeView... 阅读全文

摘要： 本例效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ComCtrls, StdCtrls; type TForm1 = class(TForm) TreeView1: TTreeVie... 阅读全文

摘要： 本例效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ComCtrls, StdCtrls; type TForm1 = class(TForm) TreeView1: TTreeVie... 阅读全文

摘要： 本例效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ComCtrls, StdCtrls; type TForm1 = class(TForm) TreeView1: TTreeVie... 阅读全文

摘要： 本例效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ComCtrls, StdCtrls, Grids, ExtCtrls; type TForm1 = class(TForm) Tr... 阅读全文

摘要： 本例效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ComCtrls, StdCtrls, Grids, ExtCtrls; type TForm1 = class(TForm) Tr... 阅读全文

摘要： 本例效果图: unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, ComCtrls, StdCtrls, Grids, ExtCtrls; type TForm1 = class(TForm) Tr... 阅读全文

摘要： 判断一个对象是否存在(赋值)的三种办法如下: if obj nil then ... if Boolean(obj) then ... if Assigned(obj) then ... 通过下面的测试, 结论是 obj nil 最慢; Boolean(obj) 与 Assigned(btn) 相当! 测试图: 测试源码: unit Unit1; interface u... 阅读全文