窗口打开时运行的 Java 方法

Question

我需要设置一个监听器，每次调用 show() 方法来显示窗口时，该监听器都可以调用一个方法。我怎样才能做到这一点？

Answer 1

您可能对 WindowListener 感兴趣。

来自the tutorial, "How to Write Window Listeners" :

The following window activities or states can precede a window event:

• Opening a window — Showing a window for the first time.
• Closing a window — Removing the window from the screen.
• Iconifying a window — Reducing the window to an icon on the desktop.
• Deiconifying a window — Restoring the window to its original size.
• Focused window — The window which contains the "focus owner".
• Activated window (frame or dialog) — This window is either the focused window, or owns the focused window.
• Deactivated window — This window has lost the focus. For more information about focus, see the AWT Focus Subsystem specification.

如果您不想实现所有这些，您可以使用 WindowAdapter ，如下:

myFrame.addWindowListener(new WindowAdapter() {
    @Override
    public void windowOpened(WindowEvent we) {
        System.out.println("this window was opened for the first time");
    }

    @Override
    public void windowActivated(WindowEvent we) {
        System.out.println("this window or a subframe was focused");
    }
});