BlogEngine.net---BlogSettings

对于博客配置，BlogEngine由一个全局配置类BlogSettings来操作，关于BlogSettings，它采用了单例设计

///<summary>
///     The blog settings singleton.
///</summary>
///<remarks>
/// This should be created immediately instead of lazyloaded. It'll reduce the number of null checks that occur
/// due to heavy reliance on calls to BlogSettings.Instance.
///</remarks>
        private static readonly Dictionary<Guid, BlogSettings> blogSettingsSingleton = new Dictionary<Guid, BlogSettings>();

///<summary>
///     Gets the singleton instance of the <see cref = "BlogSettings" /> class.
///</summary>
///<value>A singleton instance of the <see cref = "BlogSettings" /> class.</value>
///<remarks>
///</remarks>
        public static BlogSettings Instance
        {
            get
            {
                return GetInstanceSettings(Blog.CurrentInstance);
            }
        }

///<summary>
/// Returns the settings for the requested blog instance.
///</summary>
        public static BlogSettings GetInstanceSettings(Blog blog)
        {
            BlogSettings blogSettings;

            if (!blogSettingsSingleton.TryGetValue(blog.Id, out blogSettings))
            {
                lock (SyncRoot)
                {
                    if (!blogSettingsSingleton.TryGetValue(blog.Id, out blogSettings))
                    {
                        // settings will be loaded in constructor.
                        blogSettings = new BlogSettings();

                        blogSettingsSingleton[blog.Id] = blogSettings;
                    }
                }
            }

            return blogSettings;
        }

用一个键、值对集合存储博客设置的单例集合，然后获取特定的博客设置的时候，根据当前博客实例（根据当前博客的ID返回Blog.CurrentInstance）

        ///<summary>
        ///     Prevents a default instance of the <see cref = "BlogSettings" /> class from being created. 
        ///     Initializes a new instance of the <see cref = "BlogSettings" /> class.
        ///</summary>
        private BlogSettings()
        {
            this.Load();
        }

        ///<summary>        
        /// Initializes the singleton instance of the <see cref="BlogSettings"/> class.
        ///</summary>
        private void Load()
        {

            // ------------------------------------------------------------
            //     Enumerate through individual settings nodes
            // ------------------------------------------------------------
            var dic = BlogService.LoadSettings();
            var settingsProps = GetSettingsTypePropertyDict();

            foreach (System.Collections.DictionaryEntry entry in dic)
            {
                string name = (string)entry.Key;
                System.Reflection.PropertyInfo property = null;

                if (settingsProps.TryGetValue(name, out property))
                {
                    // ------------------------------------------------------------
                    //     Attempt to apply configured setting
                    // ------------------------------------------------------------
                    try
                    {
                        if (property.CanWrite)
                        {
                            string value = (string)entry.Value;
                            var propType = property.PropertyType;

                            if (propType.IsEnum)
                            {
                                property.SetValue(this, Enum.Parse(propType, value), null);
                            }
                            else
                            {
                                property.SetValue(this, Convert.ChangeType(value, propType, CultureInfo.CurrentCulture), null);
                            }
                        }
                    }
                    catch (Exception e)
                    {
                        Utils.Log(string.Format("Error loading blog settings: {0}", e.Message));
                    }
                }

            }

        }

上面的构造函数是私有的，我想应该是单例模式的需要吧。首先BlogService.LoadSettings();加载配置，然后赋值给当前实例的属性，至此初始化配置完毕。