ASP.NET MVC5学习笔记之Action参数模型绑定值提供体系

 1 public sealed class ChildActionValueProviderFactory : ValueProviderFactory
 2     {
 3         public override IValueProvider GetValueProvider(ControllerContext controllerContext)
 4         {
 5             if (controllerContext == null)
 6             {
 7                 throw new ArgumentNullException("controllerContext");
 8             }
 9 
10             return new ChildActionValueProvider(controllerContext);
11         }
12     }

 1 public sealed class FormValueProviderFactory : ValueProviderFactory
 2     {
 3         private readonly UnvalidatedRequestValuesAccessor _unvalidatedValuesAccessor;
 4 
 5         public FormValueProviderFactory()
 6             : this(null)
 7         {
 8         }
 9 
10         // For unit testing
11         internal FormValueProviderFactory(UnvalidatedRequestValuesAccessor unvalidatedValuesAccessor)
12         {
13             _unvalidatedValuesAccessor = unvalidatedValuesAccessor ?? (cc => new UnvalidatedRequestValuesWrapper(cc.HttpContext.Request.Unvalidated));
14         }
15 
16         public override IValueProvider GetValueProvider(ControllerContext controllerContext)
17         {
18             if (controllerContext == null)
19             {
20                 throw new ArgumentNullException("controllerContext");
21             }
22 
23             return new FormValueProvider(controllerContext, _unvalidatedValuesAccessor(controllerContext));
24         }
25     }

  1  public sealed class JsonValueProviderFactory : ValueProviderFactory
  2     {
  3         private static void AddToBackingStore(EntryLimitedDictionary backingStore, string prefix, object value)
  4         {
  5             IDictionary<string, object> d = value as IDictionary<string, object>;
  6             if (d != null)
  7             {
  8                 foreach (KeyValuePair<string, object> entry in d)
  9                 {
 10                     AddToBackingStore(backingStore, MakePropertyKey(prefix, entry.Key), entry.Value);
 11                 }
 12                 return;
 13             }
 14 
 15             IList l = value as IList;
 16             if (l != null)
 17             {
 18                 for (int i = 0; i < l.Count; i++)
 19                 {
 20                     AddToBackingStore(backingStore, MakeArrayKey(prefix, i), l[i]);
 21                 }
 22                 return;
 23             }
 24 
 25             // primitive
 26             backingStore.Add(prefix, value);
 27         }
 28 
 29         private static object GetDeserializedObject(ControllerContext controllerContext)
 30         {
 31             if (!controllerContext.HttpContext.Request.ContentType.StartsWith("application/json", StringComparison.OrdinalIgnoreCase))
 32             {
 33                 // not JSON request
 34                 return null;
 35             }
 36 
 37             StreamReader reader = new StreamReader(controllerContext.HttpContext.Request.InputStream);
 38             string bodyText = reader.ReadToEnd();
 39             if (String.IsNullOrEmpty(bodyText))
 40             {
 41                 // no JSON data
 42                 return null;
 43             }
 44 
 45             JavaScriptSerializer serializer = new JavaScriptSerializer();
 46             object jsonData = serializer.DeserializeObject(bodyText);
 47             return jsonData;
 48         }
 49 
 50         public override IValueProvider GetValueProvider(ControllerContext controllerContext)
 51         {
 52             if (controllerContext == null)
 53             {
 54                 throw new ArgumentNullException("controllerContext");
 55             }
 56 
 57             object jsonData = GetDeserializedObject(controllerContext);
 58             if (jsonData == null)
 59             {
 60                 return null;
 61             }
 62 
 63             Dictionary<string, object> backingStore = new Dictionary<string, object>(StringComparer.OrdinalIgnoreCase);
 64             EntryLimitedDictionary backingStoreWrapper = new EntryLimitedDictionary(backingStore);
 65             AddToBackingStore(backingStoreWrapper, String.Empty, jsonData);
 66             return new DictionaryValueProvider<object>(backingStore, CultureInfo.CurrentCulture);
 67         }
 68 
 69         private static string MakeArrayKey(string prefix, int index)
 70         {
 71             return prefix + "[" + index.ToString(CultureInfo.InvariantCulture) + "]";
 72         }
 73 
 74         private static string MakePropertyKey(string prefix, string propertyName)
 75         {
 76             return (String.IsNullOrEmpty(prefix)) ? propertyName : prefix + "." + propertyName;
 77         }
 78 
 79         private class EntryLimitedDictionary
 80         {
 81             private static int _maximumDepth = GetMaximumDepth();
 82             private readonly IDictionary<string, object> _innerDictionary;
 83             private int _itemCount = 0;
 84 
 85             public EntryLimitedDictionary(IDictionary<string, object> innerDictionary)
 86             {
 87                 _innerDictionary = innerDictionary;
 88             }
 89 
 90             public void Add(string key, object value)
 91             {
 92                 if (++_itemCount > _maximumDepth)
 93                 {
 94                     throw new InvalidOperationException(MvcResources.JsonValueProviderFactory_RequestTooLarge);
 95                 }
 96 
 97                 _innerDictionary.Add(key, value);
 98             }
 99 
100             private static int GetMaximumDepth()
101             {
102                 NameValueCollection appSettings = ConfigurationManager.AppSettings;
103                 if (appSettings != null)
104                 {
105                     string[] valueArray = appSettings.GetValues("aspnet:MaxJsonDeserializerMembers");
106                     if (valueArray != null && valueArray.Length > 0)
107                     {
108                         int result;
109                         if (Int32.TryParse(valueArray[0], out result))
110                         {
111                             return result;
112                         }
113                     }
114                 }
115 
116                 return 1000; // Fallback default
117             }
118         }
119     }

 1  public sealed class RouteDataValueProviderFactory : ValueProviderFactory
 2     {
 3         public override IValueProvider GetValueProvider(ControllerContext controllerContext)
 4         {
 5             if (controllerContext == null)
 6             {
 7                 throw new ArgumentNullException("controllerContext");
 8             }
 9 
10             return new RouteDataValueProvider(controllerContext);
11         }
12     }

 1 public sealed class QueryStringValueProviderFactory : ValueProviderFactory
 2     {
 3         private readonly UnvalidatedRequestValuesAccessor _unvalidatedValuesAccessor;
 4 
 5         public QueryStringValueProviderFactory()
 6             : this(null)
 7         {
 8         }
 9 
10         // For unit testing
11         internal QueryStringValueProviderFactory(UnvalidatedRequestValuesAccessor unvalidatedValuesAccessor)
12         {
13             _unvalidatedValuesAccessor = unvalidatedValuesAccessor ?? (cc => new UnvalidatedRequestValuesWrapper(cc.HttpContext.Request.Unvalidated));
14         }
15 
16         public override IValueProvider GetValueProvider(ControllerContext controllerContext)
17         {
18             if (controllerContext == null)
19             {
20                 throw new ArgumentNullException("controllerContext");
21             }
22 
23             return new QueryStringValueProvider(controllerContext, _unvalidatedValuesAccessor(controllerContext));
24         }
25     }

 1 public sealed class HttpFileCollectionValueProviderFactory : ValueProviderFactory
 2     {
 3         public override IValueProvider GetValueProvider(ControllerContext controllerContext)
 4         {
 5             if (controllerContext == null)
 6             {
 7                 throw new ArgumentNullException("controllerContext");
 8             }
 9 
10             return new HttpFileCollectionValueProvider(controllerContext);
11         }
12     }