我想寫一個自己用的vcl出來,如TMyEdit,這個是inherited from TEdit,請問應該怎樣做? unit TestUnit; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, UnitClass; type TForm1 = class(TForm) Edit1: TMyEdit; private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} end. unit UnitClass; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls; type TMyEdit = class(TEdit) private { Private declarations } public { Public declarations } end; implementation end. 當我compile時會有問題,不能用TMyEdit作為declaration,請問怎麼解決呢?

我想應該是,如果你的TMyEdit不是component的話,只能放在TForm的Private,Protected,Publish等區域....,試著把Edit1: TMyEdit這行放到Private試試看

還是不行,會有另外一個error,我想問有沒有什麼方法可以自己做到vcl出來呢?我看到經常網上也有一些vcl component可以下載,謝

Want to use your edit component at design time? RegisterComponents in procedure Register... and perhaps create your own package. http://pywong.hk.st http://www.lazybones.ca

如果不create一個實體化的vcl也可以,但至少能做到inherit一些現有的class/object,好讓我可以加入自己的component,請問其做法如何呢?

請問有冇example呢?或講清楚一點呢? thx

如果你要寫自己的component的話,可以參考Delphi的source,在 C:\Program Files\Borland\Delphi6\Source\Vcl\ExtCtrls.pas裡, 可以參考TCustomLabeledEdit的寫法 希望這對你有幫助

首先您可以在 Component/New Component 建立所繼承的類別。如 TEDIT 事實上，直接參考 StdCtrls,Controls 就很夠用了。 最後元件需要註冊後。才能在設計時建立控件使用。 如： procedure Register; implementation procedure Register; begin RegisterComponents('分頁名稱', [TMyEdit]); end; 以下是我寫的繼承 Tedit 的控件。(寫的不是很好！請見諒！) 您可以參考一下！ unit Evedit; interface uses Sysutils,Classes,StdCtrls,Messages,Controls,Forms,Windows,Graphics; const NumChars: set of Char = ['0'..'9']; CM_ChangeAlign = WM_USer 9999; type TevEditType = (evNone,evWord,evInteger,evFloat); TEvEdit = class(TEdit) private Alignment : TAlignment; FFocusAlignment : TAlignment; FNoFocusAlignment : TAlignment; FEditType : TevEditType; FPrecision : Byte; FDecimals : Byte; FEnterNext : Boolean; KeyPressed : Boolean; IsLoaded : Boolean; FCTL3D : Boolean; FBcolor : Tcolor; CharSet : set of Char; FBStyle : TBorderStyle; function GetFloat: Double; function GetInteger: Integer; function NoValidValue: Boolean; procedure SetBorderStyle(Value: TBorderStyle); procedure SetAlignment(Value: TAlignment); procedure SetNoFocusAlignment(Value: TAlignment); Procedure SetCTL3D(Value:Boolean); Procedure SetColor(Value:Tcolor); procedure SetEditType (Value: TevEditType); procedure CMChangeAlign(Var MSg:Tmessage);Message CM_ChangeAlign; protected procedure DrawBorder; procedure CreateParams(var Params: TCreateParams); override; procedure KeyPress(var Key: Char);override; procedure WndProc(var Message: TMessage); override; procedure DoEnter; override; procedure DoExit; override; procedure Loaded; override; procedure Change; override; procedure WMPaint(var Message: TWMPaint); message WM_PAINT; Public constructor Create(AOwner: TComponent); override; procedure FormatValue; published Property BorderColor:Tcolor read FBcolor write SetColor default clgray; Property Ctl3D:Boolean read FCTL3D write SetCTL3D; property BorderStyle: TBorderStyle read FBStyle write SetBorderStyle; property FocusAlignment :TAlignment read FFocusAlignment write FFocusAlignment default taLeftJustify ; property NoFocusAlignment :TAlignment read FNoFocusAlignment write SetNoFocusAlignment default taLeftJustify; property Precision : Byte index 0 read FPrecision write FPrecision; property Decimals : Byte index 1 read FDecimals write FDecimals; property EditType : TevEditType read fEditType write SetEditType; Property EnterNextCTRL:Boolean Read fEnterNext Write fEnterNext; Property Align; end; procedure Register; implementation procedure Register; begin RegisterComponents('Evon', [TEvEdit]); end; constructor TEvEdit.Create; begin inherited Create(AOwner); FEditType :=evNone; Alignment :=taLeftJustify; Precision :=15; FCTL3D :=True; FBStyle :=bsSingle; FBcolor :=clgray; FFocusAlignment :=taLeftJustify; FNoFocusAlignment :=taLeftJustify; end; procedure TEvEdit.CreateParams(var Params: TCreateParams); begin inherited CreateParams(Params); case Alignment of taLeftJustify :Params.Style:=Params.Style or ES_LEFT; taRightJustify :Params.Style:=Params.Style or ES_RIGHT; taCenter :Params.Style:=Params.Style or ES_CENTER; end; end; procedure TEvEdit.SetBorderStyle(Value: TBorderStyle); begin if FBStyle <> Value then begin FBStyle := Value; if AutoSize then TEdit(Self).BorderStyle := FBStyle else TEdit(Self).BorderStyle := BsSingle; RecreateWnd; end; end; procedure TEvEdit.SetAlignment(Value: TAlignment); begin if Value <> Alignment then begin Alignment:=Value; RecreateWnd; end; end; procedure TEvEdit.SetNoFocusAlignment(Value: TAlignment); begin if Value <> FNoFocusAlignment then begin FNoFocusAlignment:=Value; SetAlignment(FNoFocusAlignment); end; end; Procedure TEvEdit.SetColor(Value:Tcolor); begin if fbColor<>Value then begin Fbcolor := Value; Invalidate; end; end; procedure TEvEdit.SetEditType(Value: TevEditType); begin FEditType:=Value; case FEditType of evInteger : CharSet:=NumChars ['-']; evFloat : CharSet:=NumChars ['-'] [DecimalSeparator] ['E']; EvWord : CharSet:=NumChars; evNone : CharSet:=[]; end; if csDesigning in ComponentState then begin if FEditType <> evNone then begin FocusAlignment :=taLeftJustify; NoFocusAlignment :=taRightJustify; if NoValidValue then Text:='0'; FormatValue; end; end; end; procedure TEvEdit.KeyPress(var Key: Char); begin if FEditType <> evNone then begin if Key = '-' then begin if Pos('-',Text) > 0 then if SelLength > 0 then Text:='' else Key:=#0; if (SelLength = 0) and (SelStart > 0) then Key:=#0; end; if (Key = DecimalSeparator) and (Pos(DecimalSeparator,Text) > 0) then if SelLength > 0 then Text:='' else Key:=#0; if not (((Key>#0) and (Key <#32)) or (Key in CharSet)) then Key:=#0; end; if (Key=#13) and EnterNextCTRL then (Owner as TControl).Perform(WM_NEXTDLGCTL,0,0); inherited; KeyPressed:=True; end; function TEvEdit.GetFloat: Double; begin Result:=0.0; if not NoValidValue then Result:=StrToFloat(Text); end; function TEvEdit.GetInteger: Integer; var Error: Integer; begin Result:=0; if Length(Text) > 0 then Val(Text,Result,Error); end; function TEvEdit.NoValidValue: Boolean; var N: Byte; begin Result:=False; if FEditType = evNone then Exit; Text:=Trim(Text); if Length(Text) > 0 then begin for N:=1 to Length(Text) do if not (Text[N] in CharSet) then Result:=True; if not Result then if (FEditType = evInteger) or (FEditType = evFloat) then begin N:=Pos('-',Text); if (N > 1) or ((N > 0) and (Length(Text) < 2)) then Result:=True; end; end else Result:=True; end; procedure TEvEdit.FormatValue; begin case fEditType of evNone : if MaxLength > 0 then Text:=Copy(Text,1,Succ(MaxLength)); evFloat : Text:=FloatToStrF(GetFloat,ffFixed,FPrecision,FDecimals); evInteger,evWord : Text:=IntToStr(GetInteger); end; Repaint; end; procedure TEvEdit.Loaded; begin inherited; FormatValue; SetAlignment(FNoFocusAlignment); IsLoaded:=True; end; procedure TEvEdit.DoEnter; begin inherited; Invalidate; end; procedure TEvEdit.DoExit; begin inherited; FormatValue; end; procedure TEvEdit.Change; begin inherited; if IsLoaded and not KeyPressed then FormatValue; end; procedure TEvEdit.WndProc(var Message: TMessage); begin case Message.Msg of WM_SETFOCUS:PostMessage(Handle,CM_ChangeAlign,1,1); cm_Exit: begin PostMessage(Handle,CM_ChangeAlign,0,0); KeyPressed:=False; end; end; inherited; end; procedure TEvEdit.CMChangeAlign(Var MSg:Tmessage); begin if Msg.WParam=1 then SetAlignment(FFocusAlignment) else SetAlignment(FNoFocusAlignment); if (MSG.LParam=1) and autoSelect then SelectAll; end; Procedure TEvEdit.SetCTL3D(Value:Boolean); begin if FCTL3D<>Value then begin FCTL3D := Value; if AutoSize then TEdit(Self).CTL3D := FCTL3D else TEdit(Self).CTL3D := True; if FCTL3D then RecreateWnd else Invalidate; end; end; procedure TEvEdit.DrawBorder; var DC : HDC; ARect : TRect; I : integer; begin if (CTL3D and (BorderStyle=bsSingle)) or (AutoSize and (CTL3D or (BorderStyle=bsNone))) then Exit; DC := GetWindowDC(Handle); Try GetWindowRect(Handle, ARect); OffsetRect(ARect, -ARect.Left, -ARect.Top); if (Not AutoSize) and ((Not CTL3D ) or (BorderStyle=bsNone)) then For i:=0 to 1 do FrameRect(DC,Rect(Arect.Left I,Arect.Top I,Arect.Right-I,Arect.Bottom-I) ,Brush.handle); if (Not CTL3D ) and (BorderStyle=bsSingle) then begin Brush.Color :=BorderColor; FrameRect(DC,Arect,Brush.handle); Brush.Color :=Color; end; finally ReleaseDC (Handle, DC); end; end; procedure TEvEdit.WMPaint(var Message: TWMPaint); begin inherited; DrawBorder; end; end.

我有個少問題要補充問一問,就是當我寫完剛才上面的code後,當我build成一個pakcage時,郤沒有得install至我想要的分頁上,只有compile可以用,為什麼呢? 還有如果我是inherited from tcomponent則可以用到install功能 請指教一下