当前文件： SmallBusinessStarterKit/App_Code/News/News.cs[1K，2009-6-12 11:54:21]，打开代码结构图

		            
 1using System;
 2using System.Collections.Generic;
 3using System.Configuration;
 4using System.Web.Configuration;
 5
 6
 7/**////<summary>
 8/// class News
 9/// Provides static functions to access News
10/// and serves as abastraction layer between the web Page and
11/// actual data providers
12///</summary>
13public static class News
14...{
15
16    private static bool _isInitialized = false;
17    private static NewsProvider _provider;
18    private static SmallBusinessDataProvidersSection _providersSection;
19    
20    
21    public static NewsProvider Provider
22    ...{
23        get
24        ...{
25            Initialize();
26            return _provider;
27        }
28    }
29
30    public static List<NewsItem> GetAllNews()
31    ...{
32        return Provider.GetAllNews();
33    }
34
35    public static NewsItem GetNewsItem(string newsItemId)
36    ...{
37        return Provider.GetNewsItem(newsItemId);
38    }
39    
40    private static void Initialize()
41    ...{
42        if (!_isInitialized)
43        ...{
44            _providersSection = (ConfigurationManager.GetSection("SmallBusinessDataProviders")) as SmallBusinessDataProvidersSection;
45            if (_providersSection == null)
46            ...{
47                throw new InvalidOperationException(Messages.NewsConfigSectionNotFound);
48            }
49
50            _provider = ProvidersHelper.InstantiateProvider(_providersSection.NewsProviders[_providersSection.NewsProviderName],
51                typeof(NewsProvider)) as NewsProvider;
52
53            if (_provider == null)
54            ...{
55                throw new InvalidOperationException(Messages.NewsProviderInstantiationError);
56            }
57            _isInitialized = true;
58        }
59    }
60} // end class
61
62