TEdit和TQuery

Question

我有课：

TcvDbedit = class(TCustomMaskEdit)
...
private
  ...
  fQuery: TQuery;
  ...
protected
  ...
public
  constructor Create(AOwner: TComponent); override;
  destructor Destroy; override;
  ...
published
  ...
  property DataQuery: TQuery read fQuery write fQuery;
  ...

通过这种方式，我可以将TQuery作为属性，并可以更改属性查询。我需要一些其他的东西，来改变tQuery的属性并将它们保存在dfm中。我不希望TQuery在形式上可见。实际上我和TFDQuery一起工作。我怎样才能做到这一点？

Answer 1

也许你需要SetSubComponent。

Answer 2

不要将fQuery公开为TcvDbEdit的公共成员，而是公开所需的属性-

interface

TcvDbedit = class(TCustomMaskEdit)
private
  fQuery: TQuery;
  procedure SetSQL(AValue : String);
  function GetSQL;
public
  constructor Create(AOwner: TComponent); override;
  destructor Destroy; override;
published
  property SQL : TStrings read GetSQL write SetSQL;
end;

implementation

constructor TcvDbedit.Create(AOwner : TComponent);
begin
  fQuery = TQuery.Create(self);
end

destructor TcvDbedit.Destroy;
begin
   fQuery.Free;
end;

procedure TcvDbedit.SetValue(AValue : String);
begin
  fQuery.SQL.Assign(AValue);
end;

function TcvDbedit.GetSQL : TStrings;
begin
  return fQuery.SQL;
end;