15.
MenuItem
MenuItem是菜单树中的"叶子节点"。MenuItem通常被添加到一个Menu中。对于MenuItem对象可以添加ActionListener,使其能够完成相应的操作。
Menu m1 = new Menu("File");
MenuItem mi1 = new MenuItem("Save");
MenuItem mi2 = new MenuItem("Load");
MenuItem mi3 = new MenuItem("Quit");
m1.add(mi1);
m1.add(mi2);
m1.addSeparator();
m1.add(mi3);
查看运行结果
MenuBar和Menu都没有必要注册监听器,只需要对MenuItem添加监听器ActionListener,完成相应操作。
16. 组件与监听器的对应关系
下表中列出了各个组件与所有的监听器的对应关系,打上" "表明该组件可以注册此种监听器。
表5.2
| 监听器接口 |
Act
|
Adj
|
Cmp
|
Cnt
|
Foc
|
Itm
|
Key
|
Mou
|
MM
|
Text
|
Win
|
| Button |
|
|
|
|
|
|
|
|
|
|
|
| Canvas |
|
|
|
|
|
|
|
|
|
|
|
| Checkbox |
|
|
|
|
|
|
|
|
|
|
|
| CheckboxMenuItem |
|
|
|
|
|
|
|
|
|
|
|
| Choice |
|
|
|
|
|
|
|
|
|
|
|
| Component |
|
|
|
|
|
|
|
|
|
|
|
| Container |
|
|
|
|
|
|
|
|
|
|
|
| Dialog |
|
|
|
|
|
|
|
|
|
|
|
| Frame |
|
|
|
|
|
|
|
|
|
|
|
| Label |
|
|
|
|
|
|
|
|
|
|
|
| List |
|
|
|
|
|
|
|
|
|
|
|
| MenuItem |
|
|
|
|
|
|
|
|
|
|
|
| Panel |
|
|
|
|
|
|
|
|
|
|
|
| Scrollbar |
|
|
|
|
|
|
|
|
|
|
|
| ScrollPane |
|
|
|
|
|
|
|
|
|
|
|
| TextArea |
|
|
|
|
|
|
|
|
|
|
|
| TextField |
|
|
|
|
|
|
|
|
|
|
|
| Window |
|
|
|
|
|
|
|
|
|
|
|
Act=ActionListener Adj=AdjustmentListener
Cmp=ComponentListener
Cnt=ConatainerListener Foc=FocusListener Itm=ItemListener
Key=KeyListener Mou=MouseListener MM=MouseMotionListener
Text=TextListener Win=WindowListener
|
|