前台
   ajax  $.ajax({                     
        url: "http://xx/api/UserLogout",          
 type: "post",           
        contentType: "application/json",
                dataType: "text",
                data: JSON.stringify(RequestContent),
                success: function (result, status) {
                    alert(result)
                },
                error: function (error) {
                    alert(error);

                }
            });**
后台方法：  
   public IHttpActionResult UserLogout(RequestContent request)
           {}
RequestContent的类
public class RequestContent
                    {
                      public string Token { get; set; }
                      public string Content { get; set; }
                    }
ajax date传递这个 RequestContent