单击JMenuItem时执行操作？ [英] Performing an action when an JMenuItem is clicked?

问题描述

所以我在框架的顶部创建了一个带有基本菜单的简单程序，现在我只需要在每个JMenuItem后面放置动作。我努力工作代码，这是我认为可行的：

So i have made a simple program with a basic menu at the top of the frame, Now i just need to put actions behind each JMenuItem. Im struggling to work the code out though, Here is what i thought would work:

JMenu file_Menu = new JMenu("File");
JMenuItem fileExit = new JMenuItem("Exit Program"); 
file_Menu.add(fileExit);
fileExit.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent ae) {
        JFrame hello = new JFrame("POPUP");
        hello.setSize(100,75);
        hello.setDefaultCloseOperation(hello.EXIT_ON_CLOSE);
        hello.setVisible(true);
    }
});
main_Menu.add(file_Menu);

这似乎不起作用，我认为这段代码会创建一个小的弹出窗口单击菜单项。

This doesn't seem to work though, I thought that this code would create a small popup window when the menu item is clicked.

任何可以找到错误的因为我似乎无法看到。

Can any spot the bug because i cant seem to.

推荐答案

建议：不要添加单独的 ActionListener ，只需使用 AbstractAction ：

Suggestion: Instead of adding a separate ActionListener, just use AbstractAction:

JMenuItem fileExit = new JMenuItem(new AbstractAction("Exit Program") {
    public void actionPerformed(ActionEvent ae) {
        JFrame hello = new JFrame("POPUP");
        hello.setSize(100,75);
        hello.setDefaultCloseOperation(hello.EXIT_ON_CLOSE);
        hello.setVisible(true);
    }
});

我还建议，而不是设置 EXIT_ON_CLOSE 在弹出菜单上，将其设置在应用程序的主框架上，然后让操作只需调用 theMainFrame.dispose（）。

I'd also suggest, instead of setting EXIT_ON_CLOSE on the popup menu, you set it on the main frame of your application, and have the action simply call theMainFrame.dispose().

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