SWT：箭头按钮

 public static void showArrowButton(Shell shell)
 {
  //箭头按钮是带有小箭头的按钮，创建时还要指定箭头的方向
  //SWT.UP, SWT.DOWN, SWT.LEFT, SWT.RIGHT
  //若不指定方向，默认为SWT.UP
  Button bt1 = new Button(shell, SWT.ARROW | SWT.UP);
  bt1.setToolTipText("SWT.LEFT");
  
  Button bt2 = new Button(shell, SWT.ARROW | SWT.DOWN);
  bt2.setToolTipText("SWT.RIGHT");
  
  Button bt3 = new Button(shell, SWT.ARROW | SWT.LEFT);
  bt3.setToolTipText("CENTER");
  
  Button bt4 = new Button(shell, SWT.ARROW | SWT.RIGHT);
  bt4.setToolTipText("SWT.FLAT");
  
  Button bt5 = new Button(shell, SWT.ARROW | SWT.FLAT);
  bt5.setToolTipText("SWT.FLAT");
  
  Button bt6 = new Button(shell, SWT.ARROW | SWT.BORDER);
  bt6.setToolTipText("SWT.BORDER");
 }