全透明窗体（效果比较好）
uses里加上ExtCtrls
procedure tform1.setformtransparent;
var
  I: Integer;
  FullRgn,
  ClientRgn,
  ControlRgn: THandle;
  Margin,
  MarginX,
  MarginY,
  X,
  Y: Integer;
  W,H,S :Integer;
  bX,bY :Integer;
  c     :TColor;
begin
  Margin := (Width - ClientWidth) div 2;
  FullRgn := CreateRectRgn(0, 0, Width, Height);
  MarginX := Margin;
  MarginY := Height - ClientHeight - Margin;
  ClientRgn := CreateRectRgn(MarginX, MarginY, MarginX + ClientWidth, MarginY + ClientHeight);
  CombineRgn(FullRgn, FullRgn, ClientRgn, RGN_DIFF);
  DeleteObject(ClientRgn);
  for I:=0 to ControlCount-1 do
  begin
    X := MarginX + Controls[I].Left;
    Y := MarginY + Controls[I].Top;
    W:=Controls[I].Width;
    H:=Controls[I].Height;
{}
    if controls[i] is timage then begin
      with controls[i] as tImage do begin
        c:=Picture.Bitmap.Canvas.Pixels[0,0];
        for bX:=0 to Picture.Bitmap.Width-1 do begin
          for bY:=0 to Picture.Bitmap.Height-1 do begin
            if Picture.Bitmap.Canvas.Pixels[bX,bY]<>c then begin
              ControlRgn := CreateRectRgn(X+bX, Y+bY, X + bX+1, Y + bY+1);
              CombineRgn(FullRgn, FullRgn, ControlRgn, RGN_OR);
              DeleteObject(ControlRgn);
            end;
          end;
        end;
      end;
    end else
{}
    if controls[i] is tShape then begin
      if W < H then S := W else S := H;
      if (Controls[i] as tshape).Shape in [stSquare, stRoundSquare, stCircle] then
      begin
        Inc(X, (W - S) div 2);
        Inc(Y, (H - S) div 2);
        W := S;
        H := S;
      end;
      Inc(W); Inc(H); Inc(S);
      case (controls[i] as tshape).Shape of
        stRectangle, stSquare:
          ControlRgn := CreateRectRgn(X, Y, X + W, Y + H);
        stRoundRect, stRoundSquare:
          ControlRgn := CreateRoundRectRgn(X, Y, X + W, Y + H, S div 4, S div 4);
        stCircle, stEllipse:
          ControlRgn:=CreateEllipticRgn(X, Y, X + W, Y + H);
      else
        ControlRgn := CreateRectRgn(X, Y, X + W, Y + H);
      end;
      CombineRgn(FullRgn, FullRgn, ControlRgn, RGN_OR);
      DeleteObject(ControlRgn);
    end else
{}
    begin
      ControlRgn := CreateRectRgn(X, Y, X + W, Y + H);
      CombineRgn(FullRgn, FullRgn, ControlRgn, RGN_OR);
      DeleteObject(ControlRgn);
    end;
  end;
  SetWindowRgn(Handle, FullRgn, True);
  DeleteObject(FullRgn);
end;

procedure TForm1.FormResize(Sender: TObject);
begin
        setformtransparent;
end;

//rock
//转载请保留此信息