中文 1972 字 毕业设计（论文）文献翻译 题 目 学生姓名 学 号 专业名称 计算机科学与技术 年 级 2025 级 指导老师 职 称 讲 师 所 在 系（院） 计算机科学与技术 2025 年 3 月 1 日Menus and ToolbarsExcerpted from "Java Swing(2Nd Edition)(O'Reilly)"by Marc Loy,Robert Eckstein etc.The JMenuBar ClassSwing'sJMenuBar class supersedes the AWTMenuBar class. This class creates a horizontal menu bar component with zero or more menus attached to it. JMenuBar uses theDefaultSingleSelectionModel as its data model because the user can raise, or activate , only one of its menus at a given time. Once the mouse pointer leaves that menu, the class removes the menu from the screen (or cancels it, in Swing lingo), and all menus again become eligible to be raised Figure 14-4 shows the class hierarchy for the JMenuBar component.Figure 14-4. JMenuBar class diagramYou can add JMenu objects to the menu bar with theadd( ) method of theJMenuBar class. JMenuBar then assigns an integer index based on the order in which the menus were added. The menu bar displays the menus from left to right on the bar according to their assigned index. In theory, there is one exception: the help menu. You are supposed to be allowed to mark one menu as the help menu; the location of the help menu is up to the L&F. In practice, trying to do this results in JMenuBar throwing an Error.Menu Bar PlacementYou can attach menu bars to Swing frames or applets in one of two ways. First, you can use thesetJMenuBar( ) method of JFrame, JDialog, JApplet, or JInternalFrame:JFrame frame = new JFrame("Menu");JMenuBar menuBar = new JMenuBar( );// Attach the menu bar to the frame.frame.setJMenuBar(menuBar);The setJMenuBar( ) method is analogous to thesetMenuBar( )...
