无法将 ObjectContent 转换为 HttpContent

Question

下面的代码 当我从 Visual Studio 在我的笔记本电脑 上运行它时有效。但是当部署到 Windows 2016 服务器上的 IIS 时，我收到 500 错误和异常（.NET Framework 4.7）：

ExceptionMessage: "Error getting value from 'Content' on 'System.Net.Http.HttpResponseMessage'."
ExceptionType   : "Newtonsoft.Json.JsonSerializationException"

InnerException
ExceptionMessage: "Unable to cast object of type 'System.Net.Http.ObjectContent' to type 'System.Net.Http.HttpContent'."
ExceptionType   : "System.InvalidCastException"

public HttpResponseMessage Get()
{
    // Entities is the Entity Framework context
    // Sessions is a proprietary table and has nothing to do with ASP.NET sessions
    var content = new Entities().Sessions
        .AsEnumerable()
        .Select(t =>
        {
            return new
            {
                t.Id,
                t.SessionId,
                t.StartTime,
                t.EndTime
            };
        });

    return new HttpResponseMessage
    {
        StatusCode = HttpStatusCode.OK,
        Content    = new ObjectContent(typeof(IEnumerable), content, new JsonMediaTypeFormatter())
    };
}

Answer 1

显然在 IIS (Windows Server 2016) 上使用 .NET 4.7 不是一个好主意。当我将我的项目降级到 4.6 时，事情开始起作用了...

无法将 ObjectContent 转换为 HttpContent

Unable to cast ObjectContent to HttpContent

c#

asp.net-web-api2