SWT：點擊後顯示工具欄按鈕下方的彈出式菜單

Question

我想在用戶點擊此按鈕時在工具欄按鈕下方顯示彈出式菜單菜單。我已閱讀關於ToolItem的SWT.DROP_DOWN樣式，但這似乎非常侷限於根據this sample的簡單物品清單。相反，我想顯示一個彈出菜單，例如複選框和單選按鈕菜單項。

Answer 1

您可以用菜單項風格SWT.CHECK，SWT.CASCADE，SWT.PUSH，SWT.RADIO，SWT.SEPARATOR see javadoc ..

所以，你可以 「掛」 SWT菜單下拉的選擇上這樣

public class Test { 

private Shell shell; 

public Test() { 
    Display display = new Display(); 
    shell = new Shell(display, SWT.SHELL_TRIM); 
    shell.setLayout(new FillLayout(SWT.VERTICAL)); 
    shell.setSize(50, 100); 

    ToolBar toolbar = new ToolBar(shell, SWT.FLAT); 
    ToolItem itemDrop = new ToolItem(toolbar, SWT.DROP_DOWN); 
    itemDrop.setText("drop menu"); 

    itemDrop.addSelectionListener(new SelectionAdapter() { 

     Menu dropMenu = null; 

     @Override 
     public void widgetSelected(SelectionEvent e) { 
      if(dropMenu == null) { 
       dropMenu = new Menu(shell, SWT.POP_UP); 
       shell.setMenu(dropMenu); 
       MenuItem itemCheck = new MenuItem(dropMenu, SWT.CHECK); 
       itemCheck.setText("checkbox"); 
       MenuItem itemRadio = new MenuItem(dropMenu, SWT.RADIO); 
       itemRadio.setText("radio1"); 
       MenuItem itemRadio2 = new MenuItem(dropMenu, SWT.RADIO); 
       itemRadio2.setText("radio2"); 
      } 

      if (e.detail == SWT.ARROW) { 
       // Position the menu below and vertically aligned with the the drop down tool button. 
       final ToolItem toolItem = (ToolItem) e.widget; 
       final ToolBar toolBar = toolItem.getParent(); 

       Point point = toolBar.toDisplay(new Point(e.x, e.y)); 
       dropMenu.setLocation(point.x, point.y); 
       dropMenu.setVisible(true); 
      } 

     } 

    }); 

    shell.open(); 

    while(!shell.isDisposed()) { 
     if(!display.readAndDispatch()) display.sleep(); 
    } 

    display.dispose(); 
} 

public static void main(String[] args) { 
    new Test(); 
} 

}