Vala：D-BUS 对象实现接口，属性错误

Posted 2023-04-14

【中文标题】Vala：D-BUS 对象实现接口，属性错误

【英文标题】：Vala: D-BUS object implementing interface, error with properties

【发布时间】：2011-10-26 12:34:19

【问题描述】：

是否可以让使用 [DBus (name = ...)] 注释的类实现接口？

按照https://live.gnome.org/Vala/DBusServerSample 的示例，我正在实现一个 D-BUS 客户端/服务器应用程序。

我发现该示例的一个特别之处是没有单独的接口定义。我想将客户端使用的接口放在一个单独的文件中，并让服务器类实现该接口。这样我可以让编译器在我错过某些内容时告诉我。

这似乎不适用于属性。以下定义与我所拥有的兼容：

/* interface.vala */
namespace org.test 
    [DBus (name = "org.test.Items")]
    public interface IItems : Object 
        /**
         * The object paths to the item instances.
         *
         * These objects are of type org.test.items.Item.
         */
        public abstract ObjectPath[] items 
            owned get;
        

        /**
         * The signal that is emitted when a new item is added.
         *
         * When this signal is emitted, the item will be available.
         *
         * @param id
         *     The object path to the item instance.
         */
        public signal void item_added(ObjectPath id);

        /**
         * The signal that is emitted when an item is removed.
         *
         * When this signal is emitted, the item will be unavailable.
         *
         * @param id
         *     The object path to the item instance.
         */
        public signal void item_removed(ObjectPath id);

        /**
         * Adds a new item.
         *
         * The URL will be parsed, and if it contains a valid item, it will be
         * added.
         *
         * @param url
         *     The URL to the item. This should typically be the URL of the
         *     RSS feed.
         * @return the ID of the item added, which can be used to query D-BUS
         *     for it
         * @throws IOError if a D-BUS error occurs
         */
        public abstract ObjectPath add_item(string url) throws IOError;

        /**
         * Removes an item.
         *
         * @param id
         *     The ID of the item to remove.
         * @throws IOError if a D-BUS error occurs
         */
        public abstract void remove_item(ObjectPath id) throws IOError;
    


/* server.vala */
using Gee;

namespace org.test 
    [DBus (name = "org.test.Items")]
    public class Items : DBUSObject, IItems 
        private ArrayList<Item> _items;

        [DBus (visible = false)]
        protected override void dbus_register(DBusConnection conn,
                ObjectPath path) throws IOError 
            conn.register_object(path, this);
        

        [DBus (visible = false)]
        public Items() 
            base("org.test.Items", "/org/test", "Items", true);
            _items = new ArrayList<Item>();
        

        [DBus (visible = false)]
        ~Items() 
            unregister();
        

        /**
         * @see interface.vala::org.test.IItems.comics
         */
        public ObjectPath[] items 
            owned get 
                ObjectPath[] result = ;
                foreach (var item in _items) 
                    result += new ObjectPath(item.path);
                
                return result;
            
        

        /**
         * @see interface.vala::org.test.IItems.add_comic
         */
        public ObjectPath add_item(string url) throws IOError 
            /* . . . */
        

        /**
         * @see interface.vala::org.test.IItems.remove_item
         */
        public void remove_item(ObjectPath id) throws IOError 
            /* . . . */
        
    

当我编译它时，我没有从 valac 得到错误，但是当编译生成的 C 代码时，链接器抱怨：undefined reference to 'org_test_items_get_items'。

这个函数被_dbus_org_test_items_get_items引用了，但是不存在

【参考方案1】：

这显然是一个错误。报告错误的正确位置是http://bugzilla.gnome.org。