function 是不是不可以多态的

Question

baseclass
Function  IsModefied:Bool;  virtual;
Function TBaseFrm.IsModefied:Bool;
var
        variContrlRec:^ZXVariContrlRecord;
        i:integer;
begin
       for i:=0 to FVariControlList.Count-1 do
       begin
            variContrlRec:=FVariControlList[i];
            if variContrlRec^.Control is TEdit then
            begin
                if (variContrlRec^.Control as TEdit).Text<>(variContrlRec^.vari)^ then
                begin
                        Result:=True;
                        exit;
                end
                else
                        Result:=False;            end;
       end;
end;
继承的class
Function  IsModefied:Bool;Override;
Function  TLFSupply_Name.IsModefied:Bool;
begin
      if Supplier.ProvinceName <>trim(cboProvince.Text)  then
      begin
        reSult:=True;
        exit
      end
      else
      result:=False;
      inherited;//出错
end;

Answer 1

你的写法有问题。
只有类成员才能多态，你的FUNCTION好象都不是类成员。

Answer 2

我的类声明如下
type
      ZXVariContrlRecord = record
        vari : ^Variant;                     //实例属性
        Control : TControl;                  //操作控件
        varType : integer;                    //实例属性的类型
        variName:String;                      //对应cds中的Fieldvalue的名字
      end;
  TBaseFrm = class(TForm)          ？？这样有问题吗
  private
    { Private declarations }  public
    { Public declarations }
     FVariControlList : TList;
     constructor Create(AOwner: TComponent); override;
     Destructor Destroy;
     procedure ClearList;Virtual;
     procedure DDX(var vari:variant;Control:TControl;varType:integer;variName:string);overload;
     procedure VCT(b:Bool); Virtual;    //vari<-__tranc_->Control
     procedure AddRecord(Var B:Bool);Virtual;
     procedure DeleteRecord();Virtual;
     procedure UpdateRecord();Virtual;
     procedure ClearVari();Virtual;
     Function  IsEmpty:Bool;     virtual;//判断实例属性是否为空
     Function  IsModefied:Bool;  virtual;//操作控件的值是否等于实例属性的值
     Function  ValidateData:Bool;virtual;
  end;var
  BaseFrm: TBaseFrm;implementation

Answer 3

这是我的代码，没有问题。type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
    function aa: boolean;virtual;
  end;
  TF = class(TForm1)
   public
   function aa: boolean;override;
  end;
var
  Form1: TForm1;implementation{$R *.dfm}{ TForm1 }function TForm1.aa: boolean;
begin
  showmessage('ok');
end;{ TF }function TF.aa: boolean;
begin
   inherited aa();
end;procedure TForm1.Button1Click(Sender: TObject);
var
 b: TF;
begin
   b := TF.Create(nil);
   b.aa;
end;end.