WebApi Put"参数字典包含参数的空条目..."

Question

public class ContactsController : ApiController
{
    private static readonly List<Contact> _contacts = new List<Contact>();
    public Contact PutContacts(int id, Contact contact)
    {
        if (_contacts.Any(c => c.Id == contact.Id) == false)
        {
            throw new HttpResponseException(HttpStatusCode.NotFound);
        }
        contact.LastModified = DateTime.Now;
        return contact;
    }
}

http put header:

PUT /api/contacts/3 HTTP/1.1
User-Agent: Fiddler
Content-Type: application/json
Host: localhost:8080

身体:

{"Id":3,"Name":"mmm","Phone":"000 000 0000","Email":"mmm@gmail.com","LastModified":"2012-03-08T23:42:13.8681395+08:00"}

响应:

HTTP/1.1 400 Bad Request
"The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'SelfHost.Contact PutContacts(Int32, SelfHost.Contact)' in 'SelfHost.ContactsController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter."

为什么？谢谢.

PS:

config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );

Answer 1

我无法重现您所描述的问题。

模型：

public class Contact
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Phone { get; set; }
    public string Email { get; set; }
    public DateTime LastModified { get; set; }
}

控制器：

public class ContactsController : ApiController
{
    public Contact Put(int id, Contact contact)
    {
        return contact;
    }
}

客户：

class Program
{
    static void Main()
    {
        using (var client = new WebClient())
        {
            client.Headers[HttpRequestHeader.ContentType] = "application/json";
            var data = Encoding.UTF8.GetBytes(@"{""Id"":3,""Name"":""mmm"",""Phone"":""000 000 0000"",""Email"":""mmm@gmail.com"",""LastModified"":""2012-03-08T23:42:13.8681395+08:00""}");
            var result = client.UploadData("http://localhost:1405/api/contacts/4", "PUT", data);
            Console.WriteLine(Encoding.UTF8.GetString(result));
        }
    }
}

当我运行客户端时，将发送以下请求：

PUT /api/contacts/4 HTTP/1.1
Content-Type: application/json
Host: localhost:1405
Content-Length: 119
Expect: 100-continue
Connection: Keep-Alive

{"Id":3,"Name":"mmm","Phone":"000 000 0000","Email":"mmm@gmail.com","LastModified":"2012-03-08T23:42:13.8681395+08:00"}

我从服务器得到了正确的结果。所以我猜您显示的请求不是发送到服务器的实际请求。