使用 GIO Actions 在 PyGI GTK 中创建完整菜单

在 GTK 应用程序中，菜单栏是一个常见的 UI 元素，用于组织和提供应用程序的功能。传统上，GTK 应用程序使用 GtkActions 来创建菜单。然而，随着 GIO 库的引入，GIO Actions 成为创建菜单的推荐方法。GIO Actions 提供了一个更灵活、更强大且更现代的方式来处理应用程序的动作和菜单。

2. 解决方案

使用 GIO Actions 创建菜单涉及以下步骤：

1. 创建一个 Gio.Menu 对象，它将作为菜单的基础。
2. 向菜单添加子菜单和菜单项。
3. 为每个菜单项关联一个 Gio.SimpleAction 对象。
4. 将菜单添加到应用程序的 AppMenu 或 Menubar 中。

以下是一个使用 GIO Actions 在 PyGI GTK 中创建完整菜单的代码示例：

#!/usr/bin/env python3

# Import the necessary libraries
from gi.repository import Gio
from gi.repository import Gtk
import sys

# Define the menu structure
menus_str = '''
<?xml version="1.0"?>
<interface>
  <menu id="appmenu">
    <section>
      <item>
        <attribute name="label" translatable="yes">Preferences</attribute>
        <attribute name="action">app.preferences</attribute>
      </item>
    </section>
    <section>
      <item>
        <attribute name="label" translatable="yes">About</attribute>
        <attribute name="action">app.about</attribute>
      </item>
      <item>
        <attribute name="label" translatable="yes">Quit</attribute>
        <attribute name="action">app.quit</attribute>
        <attribute name="accel">&lt;Primary&gt;q</attribute>
      </item>
    </section>
  </menu>
  <menu id="menubar">
    <submenu>
      <attribute name="label">_Help</attribute>
      <section>
        <item>
              <attribute name="label">_About</attribute>
              <attribute name="action">app.about</attribute>
            </item>
          </section>
        </submenu>
      </menu>
    </interface>
    '''

# Define the main application class
class App:
    def __init__(self):
        # Create the application object
        self.app = Gtk.Application.new('org.liulang.test', 0)

        # Connect to the startup, activate, and shutdown signals
        self.app.connect('startup', self.on_app_startup)
        self.app.connect('activate', self.on_app_activate)
        self.app.connect('shutdown', self.on_app_shutdown)

    # Run the application
    def run(self, argv):
        self.app.run(argv)

    # Handle the app startup signal
    def on_app_startup(self, app):
        # Create the main window
        self.window = Gtk.ApplicationWindow.new(app)
        self.window.set_default_size(640, 480)
        self.window.set_title('Gio Actions Demo')
        self.window.set_border_width(5)

        # Add the window to the application
        app.add_window(self.window)

        # Create a label to display text in the window
        label = Gtk.Label('Hello, Gtk3')
        self.window.add(label)
        label.props.halign = Gtk.Align.CENTER
        label.props.valign = Gtk.Align.CENTER

        # Create a builder to load the menu UI from a string
        builder = Gtk.Builder()
        builder.add_from_string(menus_str)

        # Connect signals to the builder objects
        builder.connect_signals(self)

        # Get the AppMenu and Menubar objects from the builder
        appmenu = builder.get_object('appmenu')
        menubar = builder.get_object('menubar')

        # Set the AppMenu and Menubar to the application
        app.set_app_menu(appmenu)
        app.set_menubar(menubar)

        # Create simple actions for the menu items
        self.add_simple_action('preferences', self.on_action_preferences_activated)
        self.add_simple_action('about', self.on_action_about_activated)
        self.add_simple_action('quit', self.on_action_quit_activated)

    # Handle the app activate signal
    def on_app_activate(self, app):
        # Show the main window
        self.window.show_all()

    # Handle the app shutdown signal
    def on_app_shutdown(self, app):
        # Do any necessary cleanup before exiting the application
        pass

    # Define the callback for the Preferences menu item
    def on_action_preferences_activated(self, action, user_data):
        print('Preferences menu item activated')

    # Define the callback for the About menu item
    def on_action_about_activated(self, action, user_data):
        print('About menu item activated')

    # Define the callback for the Quit menu item
    def on_action_quit_activated(self, action, user_data):
        # Quit the application
        self.app.quit()

    # Add a simple action to the application
    def add_simple_action(self, name, callback):
        action = Gio.SimpleAction.new(name, None)
        action.connect('activate', callback)
        self.app.add_action(action)


# Create an instance of the main application class and run the application
if __name__ == '__main__':
    app = App()
    app.run(sys.argv)

这个代码示例演示了如何使用 GIO Actions 创建一个完整的菜单，包括子菜单、菜单项、图标和热键。它还展示了如何连接动作到回调函数，以便在用户选择菜单项时执行相应的功能。

我希望这个代码示例对你有帮助。如果你有任何其他的问题，请随时向我提问。