Delphi：类属性的错误2008年不兼容的类型

Question

I have this class defined

  TParamType = (ptDriverID, ptServer, ptHost, ptUser, ptPassword, ptPort, ptDatabase, ptOSAuth, ptPooled, ptUnicode);
  TDataType = (dtInteger, dtString, dtBoolean, dtYesNo, dtPassword);


  TParam = record
    Index: Byte;
    Typ: TParamType;
    RegKeyName: String;
    ConnName: String;
    DataType: TDataType;
    Caption: String;
    Value: String;
    Text: String;
    Default: String;
    Basic: Boolean;
    Enabled: Boolean;
    Mandatory: Boolean;
  end;

  TParams = class(TObject)
    private
      FParam: array of TParam;
      function GetParam(Index:Byte): TParam;
      procedure SetParam(Index:Byte;Value:String;Text:String);
    public
      constructor Create;
      destructor Destroy;
      property Param[Index: Byte]: TParam read GetParam write SetParam;
      procedure Enable(ServerType:TServerType);
  end;

I get this error: 'E2008 Incompatible types' to the code line

property Param[Index: Byte]: TParam read GetParam write SetParam;

Any idea why I get this error for this property?

Answer 1

property Param is a TParam . Therefore, SetParam needs to receive the Index into the array and a TParam to put there. Your setter instead provides the index and two strings, neither of which are a TParam .

The proper setter would be

procedure SetParam(Index: Byte; const Value: TParam);