c++builder自定义控件

c++builder自定义控件

http://docwiki.embarcadero.com/CodeExamples/XE8/en/RegisterComponents_%28C%2B%2B%29

void __fastcall SetFocusControl(TWinControl* Value);
    void __fastcall CMDialogChar(TWMKey& Message);
    void __fastcall CMTextChanged(TMessage& Message);

protected:
    virtual void __fastcall Notification(TComponent* AComponent, TOperation Operation);
    virtual void __fastcall Paint(void);

public:
    __fastcall virtual TDemoLabel(TComponent* AOwner);

__published:
    __property Caption ;
    __property Color ;
    __property TWinControl* FocusControl = {read=FFocusControl, write=SetFocusControl, nodefault};
    __property Font ;
    __property ParentColor ;
    __property ParentFont ;
public:
    __fastcall virtual ~TDemoLabel(void) { }

BEGIN_MESSAGE_MAP
  MESSAGE_HANDLER(CM_DIALOGCHAR, TWMKey, CMDialogChar);
  MESSAGE_HANDLER(CM_TEXTCHANGED, TMessage, CMTextChanged);
END_MESSAGE_MAP(TGraphicControl);
};

void __fastcall PACKAGE Register()
{
  TComponentClass classes[] = {__classid(TDemoLabel)};
  RegisterComponents("Samples", classes, );
  RegisterComponents("MySystem", classes, );
}

__fastcall TDemoLabel::TDemoLabel(TComponent *AOwner):
    TGraphicControl(AOwner)
{
  FComponentStyle >> csInheritable;
  Width=;
  Height=;
}

void __fastcall    TDemoLabel::Notification(TComponent *AComponent, TOperation Operation)
{
  TGraphicControl::Notification(AComponent, Operation);
  if ((Operation == opRemove)  && (AComponent == FFocusControl))
    FFocusControl = ;
}

void __fastcall    TDemoLabel::SetFocusControl(TWinControl *Value)
{
  FFocusControl = Value;

  // Calling FreeNotification ensures that this component
  // will receive an opRemove when Value is either removed
  // from its owner or destroyed.

  Value->FreeNotification(Value);
}

void __fastcall    TDemoLabel::Paint()
{
  TRect    Rect = ClientRect;
  Canvas->Font = Font;
  Canvas->Brush->Color = Color;
  Canvas->FillRect(Rect);
  DrawText(
    Canvas->Handle,
    Caption.t_str(),
    Caption.Length(),
    &Rect,
    DT_EXPANDTABS | DT_WORDBREAK | DT_LEFT);
}

void __fastcall    TDemoLabel::CMDialogChar(TCMDialogKey &Message)
{
  if (FFocusControl != NULL &&
      Enabled == true &&
      IsAccel(Message.CharCode, Caption))
      if (FFocusControl->CanFocus()){
        FFocusControl->SetFocus();
        Message.Result = ;
      }
}

void __fastcall    TDemoLabel::CMTextChanged(TMessage &Message)
{
  Invalidate();
}