在Delphi中实现任意形状的窗体

form的text：

object form1: tform1
  left = 192
  top = 107
  borderstyle = bsnone
  caption = 'form1'
  clientheight = 348
  clientwidth = 536
  color = clbtnface
  font.charset = default_charset
  font.color = clwindowtext
  font.height = -11
  font.name = 'ms sans serif'
  font.style = []
  oldcreateorder = false
  oncreate = button1click
  pixelsperinch = 96
  textheight = 13
  object button1: tbutton
    left = 392
    top = 152
    width = 75
    height = 25
    caption = 'button1'
    taborder = 0
    onclick = button1click
  end
  object button2: tbutton
    left = 432
    top = 24
    width = 17
    height = 17
    caption = 'button2'
    taborder = 1
    onclick = button2click
  end
  object button3: tbutton
    left = 448
    top = 40
    width = 17
    height = 17
    caption = 'button2'
    taborder = 2
    onclick = button3click
  end
  object button4: tbutton
    left = 464
    top = 56
    width = 17
    height = 17
    caption = 'button2'
    taborder = 3
    onclick = button4click
  end
end

各种不同的事件声名：

  tform1 = class(tform)
    button1: tbutton;
    button2: tbutton;
    button3: tbutton;
    button4: tbutton;
    procedure button1click(sender: tobject);
    procedure button2click(sender: tobject);
    procedure button3click(sender: tobject);
    procedure button4click(sender: tobject);
  private
    procedure wmmove(var message: twmnchittest); message wm_nchittest;
    { private declarations }
  public
    { public declarations }
  end;

var
  form1: tform1;

implementation

{$r *.dfm}

procedure tform1.wmmove(var message: twmnchittest);
begin
  message.result :=  htcaption;
end;

procedure tform1.button1click(sender: tobject);
var
r1,r2,r3,r4,r5: hrgn;
begin
  r1 := createellipticrgn(0,0,round(clientwidth / 2),clientheight);
  r2 := createellipticrgn(round(clientwidth / 2),0,clientwidth,clientheight);
  r3 := createellipticrgn(round(clientwidth / 4 ),round(clientheight / 4 *3),round(clientwidth / 4 *3),clientheight);
  r4 := createrectrgn(0,0,0,0);
  r5 := createrectrgn(0,0,0,0);
  combinergn(r4,r2,r1,rgn_or);
  combinergn(r5,r4,r3,rgn_or);

  setwindowrgn(handle,r5,true);
  deleteobject(r1);
  deleteobject(r2);
  deleteobject(r3);
  deleteobject(r4);
  deleteobject(r5);
end;

procedure tform1.button2click(sender: tobject);
begin
  sendmessage(handle,wm_syscommand,sc_minimize,0);
end;

procedure tform1.button3click(sender: tobject);
begin
  sendmessage(handle,wm_syscommand,sc_default,0);
end;

procedure tform1.button4click(sender: tobject);
begin
  application.terminate;
end;

end.