c# - 找不到类型或命名空间名称 'FormatterContext' .net 4.5

Question

我的项目框架:.net 4.5
项目类型:MVC4
我添加了framework 4.0的System.Json。
我在 Model -> JsonNetFormatter.cs 中添加了以下代码，它继承了 MediaTypeFormatter 类:

protected override System.Threading.Tasks.Task<object> OnReadFromStreamAsync(Type type, System.IO.Stream stream, System.Net.Http.Headers.HttpContentHeaders contentHeaders, FormatterContext formatterContext)
        {
            var task = Task<object>.Factory.StartNew(() =>
                {
                    var settings = new JsonSerializerSettings()
                    {
                        NullValueHandling = NullValueHandling.Ignore,
                    };

                    var sr = new StreamReader(stream);
                    var jreader = new JsonTextReader(sr);

                    var ser = new JsonSerializer();
                    ser.Converters.Add(new IsoDateTimeConverter());

                    object val = ser.Deserialize(jreader, type);
                    return val;
                });

            return task;
        }

但是当我要构建解决方案或我的项目时，它会抛出以下错误:

找不到类型或命名空间名称“FormatterContext”(是否缺少 using 指令或程序集引用？)

我是否缺少任何 dll 或由于其他原因，它抛出错误？

Answer 1

FormatterContext 在 MVC4 RC 版本中被移除

请引用发行说明:Release notes

来自:MSDN Forums

Formatter improvements: The methods on MediaTypeFormatter are now public to enable unit testing of custom formatters. A single formatter can now support multiple text encodings. Use BufferedMediaTypeFormatter to implement simple synchronous formatting support. FormatterContext has been removed. To get access to the request from a formatter on the server implement GetPerRequestFormatterInstance.