json.net – 找不到方法：’Newtonsoft.Json.JsonSerializerSettings Microsoft.AspNet.Mvc.MvcJsonOptions.get_SerializerSettings()’

本地我的项目运行正常,但当我使用Web应用程序在Azure上部署时,我在启动时收到以下错误： @H_726_1@missingMethodException：找不到方法：’Newtonsoft.Json.JsonserializerSetTings Microsoft.AspNet.Mvc.Formatters.JsonOutputFormatter.get_serializerSetTings()’.
smartAdmin.Startup.<> c.b__13_7(MvcOptions选项)

我试过这个：

services.AddMvc(options =>
        {
                options.Filters.Add(new UserPreferencesLoaderAtrribute());
                var jsonFormatter = (JsonOutputFormatter)options.OutputFormatters.FirstOrDefault(f => f is JsonOutputFormatter);
                if (jsonFormatter != null)
                {
                jsonFormatter.serializerSetTings.ContractResolver = new CamelCasePropertyNamesContractResolver();
            }
        });

还有这个：

services.AddMvc(options =>
        {
            options.Filters.Add(new UserPreferencesLoaderAtrribute());

        }).AddJsonOptions(options =>
        {
            options.serializerSetTings.ContractResolver = new CamelCasePropertyNamesContractResolver();
        });

services.AddMvc().AddJsonOptions(options =>
    {
        options.serializerSetTings.ContractResolver = new CamelCasePropertyNamesContractResolver();
    });