怎么把一个控件简单的改成圆形？

Question

怎么把一个控件简单的改成圆形？

Answer 1

API,自己去查吧，论坛里想必很多HGDIOBJ SelectObject(    HDC hdc, // handle of device context 
    HGDIOBJ hgdiobj  // handle of object  
   );
 
Region CombineRgn, CreateEllipticRgn, CreateEllipticRgnIndirect, CreatePolygonRgn, CreateRectRgn, CreateRectRgnIndirect

Answer 2

重新处理paint事件，爱怎样画就怎样画吧！！

Answer 3

怎样能把button画成圆形外观
TButtonTest = class(TGraphicControl)
public
  constructor Create(aOwner: TComponent); override;
protected
  procedure Paint; override;
end;constructor TButtonTest.Create(aOwner: TComponent);
begin
  inherited;
  Height:=50;
  Width:=100;
end;procedure TButtonTest.Paint;
begin
  inherited;
  Canvas.Brush.Style:=bsClear;
  Canvas.Pen.Color:=clBlue;
  Canvas.Brush.Color:=clGreen;
  Canvas.RoundRect(0,0,Width,Height,8,8);//圆角矩形
  Canvas.Ellipse(0,0,Width,Height);//椭圆
end;var Btn:TButtonTest;Btn:=TButtonTest.Create(self);
Btn.Parent:=Self;
椭圆形按钮：
type
  TRbutton=class(TButton)
private
  .......
protected
  procedure CreateWnd;override;
  ........
  ........
procedure TRbutton.CreateWnd;//在控件一建立就设置
var
  hRgn ：THandle;
begin
  inherited  CreateWnd;
  hRgn:=CreateEllipticRgn(0,0,Width,Height);//创建一个椭圆剪裁域；
  SetWindowRgn(Handle,hRgn,True);
end;