MVC自定义JsonDataGridResult_.NET_编程开发_程序员俱乐部

在用EasyUI的时候为了返回Datagrid能够展现出来的Json数据格式，都要这样写

 public JsonResult GetAllSchoolsJson()
        {
            var result = IStudentLogic.GetAllStudent();//result 返回自定义的InvokeWebResult<T> 这里是分页返回的就是InvokeWebResult<PagedList<T>>
            return Json(new { total = result.Data.Count, rows = result.Data.Items }, JsonRequestBehavior.AllowGet);

        }
        //或者
        public JsonResult GetAllSchoolsJson()
        {
            var result = IStudentLogic.GetAllStudent();
            new JsonResult
            {
                Data = new
                {
                    total = result.Data.Count,
                    rows = result.Data.Items
                }
            };
        }

//InvokeWebResult<T>  InvokeWebResult<PagedList<T>>

namespace WebSeat.Core
{
    /// <summary>
    /// Class PagedList
    /// </summary>
    /// <typeparam name="T"></typeparam>
    [Serializable]
    public class PagedList<T>
    {
        /// <summary>
        /// Gets or sets the index.
        /// </summary>
        /// <value>The index.</value>
        public int Index { get; set; }
        /// <summary>
        /// Gets or sets the size.
        /// </summary>
        /// <value>The size.</value>
        public int Size { get; set; }
        /// <summary>
        /// Gets or sets the count.
        /// </summary>
        /// <value>The count.</value>
        public int Count { get; set; }
        /// <summary>
        /// Gets or sets the items.
        /// </summary>
        /// <value>The items.</value>
        public IList<T> Items { get; set; }
        /// <summary>
        /// 总页数
        /// </summary>
        public int TotalPageCount
        {
            get { return (int)Math.Ceiling(Count / (double)Size); }
        }
    }
}

namespace WebSeat.Web.Core
{
    /// <summary>
    ///     操作结果
    /// </summary>
    /// <typeparam name="T">附加数据类型</typeparam>
    [Serializable]
    public class InvokeWebResult<T>
    {
        /// <summary>
        ///     操作是否成功
        /// </summary>
        /// <value><c>true</c> if success; otherwise, <c>false</c>.</value>
        public bool Success { get; set; }

        /// <summary>
        ///     操作结果信息
        /// </summary>
        /// <value>The message.</value>
        public string Message { get; set; }

        /// <summary>
        ///     附加数据
        /// </summary>
        /// <value>The data.</value>
        public T Data { get; set; }
        
        public InvokeWebResult()
        {
            Success = false;
        }
    }
}

每次都Return Json(…………)，或者 new JsonResult{……}, 它们内部实现我们不能控制，但是底层返回来的都是统一的InvokeWebResult<T> ，我们在Controller里把返回的数据格式都统一转换成

new { total = …………, rows = ………… }，，感觉这是一个重复的工作，满篇的total=…… rows=…… ，于是想自己专门定义一个针对EasyUI Datagrid的Result,MVC是个开源的框架，可以自己下载源码然后研究，我看了下在Controller里的实现，其实 Json 也就是调用的JsonResult代码如下

protected internal JsonResult Json(object data, string contentType)
        {
            return Json(data, contentType, null /* contentEncoding */, JsonRequestBehavior.DenyGet);
        }

        protected internal virtual JsonResult Json(object data, string contentType, Encoding contentEncoding)
        {
            return Json(data, contentType, contentEncoding, JsonRequestBehavior.DenyGet);
        }

        protected internal JsonResult Json(object data, JsonRequestBehavior behavior)
        {
            return Json(data, null /* contentType */, null /* contentEncoding */, behavior);
        }

        protected internal JsonResult Json(object data, string contentType, JsonRequestBehavior behavior)
        {
            return Json(data, contentType, null /* contentEncoding */, behavior);
        }

        protected internal virtual JsonResult Json(object data, string contentType, Encoding contentEncoding, JsonRequestBehavior behavior)
        {
            return new JsonResult
            {
                Data = data,
                ContentType = contentType,
                ContentEncoding = contentEncoding,
                JsonRequestBehavior = behavior
            };
        }

再查看了MVC内部JsonResult 的实现，其实很简单，就是继承ActionResult 然后重写ExecuteResult方法

namespace System.Web.Mvc
{
    public class JsonResult : ActionResult
    {
        public JsonResult()
        {
            JsonRequestBehavior = JsonRequestBehavior.DenyGet;
        }

        public Encoding ContentEncoding { get; set; }

        public string ContentType { get; set; }

        public object Data { get; set; }

        public JsonRequestBehavior JsonRequestBehavior { get; set; }

        /// <summary>
        /// When set MaxJsonLength passed to the JavaScriptSerializer.
        /// </summary>
        public int? MaxJsonLength { get; set; }

        /// <summary>
        /// When set RecursionLimit passed to the JavaScriptSerializer.
        /// </summary>
        public int? RecursionLimit { get; set; }

        public override void ExecuteResult(ControllerContext context)
        {
            if (context == null)
            {
                throw new ArgumentNullException("context");
            }
            if (JsonRequestBehavior == JsonRequestBehavior.DenyGet &&
                String.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase))
            {
                throw new InvalidOperationException(MvcResources.JsonRequest_GetNotAllowed);
            }

            HttpResponseBase response = context.HttpContext.Response;

            if (!String.IsNullOrEmpty(ContentType))
            {
                response.ContentType = ContentType;
            }
            else
            {
                response.ContentType = "application/json";
            }
            if (ContentEncoding != null)
            {
                response.ContentEncoding = ContentEncoding;
            }
            if (Data != null)
            {
                JavaScriptSerializer serializer = new JavaScriptSerializer();
                if (MaxJsonLength.HasValue)
                {
                    serializer.MaxJsonLength = MaxJsonLength.Value;
                }
                if (RecursionLimit.HasValue)
                {
                    serializer.RecursionLimit = RecursionLimit.Value;
                }
                response.Write(serializer.Serialize(Data));
            }
        }
    }
}

于是我想到，自己也写一个类，来继承JsonResult,然后重写ExecuteResult方法，以后每次处理从下层返回来的数据的时候只需要调用自己的实现，进行统一的转换，不再是满篇的 total=……  rows=……，万一客户端不是EasyUi Datagrid了就哭了，满篇改，不能有重复的代码，我有强迫症，见到这种就看不惯。

namespace WebSeat.Web.Core.EasyUi
{
    // public class JsonDataGridResult<T> : JsonResult where T : class
    //{
    //自己也继承JsonResult方法  重写ExecuteResult方法
    public class JsonDataGridResult : JsonResult
    {
        public JsonDataGridResult(dynamic obj)
        {
            JsonRequestBehavior = JsonRequestBehavior.AllowGet;
            Data = new DataGrid
            {
                rows = obj == null ? null : obj.Items,
                total = obj == null ? 0 : obj.Count
            };
        }

        #region Temp Methods

        public JsonDataGridResult(IEnumerable<object> obj)
        {
            JsonRequestBehavior = JsonRequestBehavior.AllowGet;
            Data = new DataGrid
            {
                rows = obj,
                total = obj == null ? 0 : obj.Count()
            };
        }
        public JsonDataGridResult(IEnumerable<object> obj, int total)
        {
            JsonRequestBehavior = JsonRequestBehavior.AllowGet;
            Data = new DataGrid
            {
                rows = obj,
                total = total
            };
        }
        #endregion
        //public JsonDataGridResult(PagedList<T> obj)
        //{
        //    JsonRequestBehavior = JsonRequestBehavior.AllowGet;
        //    Data = new DataGrid
        //    {
        //        rows = obj.Items,
        //        total = obj.Count
        //    };
        //}

        public override void ExecuteResult(ControllerContext context)
        {
            if (context == null)
            {
                throw new ArgumentNullException("context");
            }
            //这个不要了
            /*if (JsonRequestBehavior == JsonRequestBehavior.DenyGet &&
                String.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase))
            {
                throw new InvalidOperationException(WebCoreMessages.JsonRequest_GetNotAllowed);
            }*/
            HttpResponseBase response = context.HttpContext.Response;
            response.ContentType = !String.IsNullOrEmpty(ContentType) ? ContentType : "application/json";
            if (ContentEncoding != null)
            {
                response.ContentEncoding = ContentEncoding;
            }
            if (Data != null)
            {
                var serializer = new JavaScriptSerializer();
                if (MaxJsonLength.HasValue)
                {
                    serializer.MaxJsonLength = MaxJsonLength.Value;
                }
                if (RecursionLimit.HasValue)
                {
                    serializer.RecursionLimit = RecursionLimit.Value;
                }
                response.Write(serializer.Serialize(Data));
            }
        }
    }
}

以后每次返回给Datagrid数据的时候都这样写了,

  public JsonResult GetAllSchoolsJson()
        {
            var result = IStudentLogic.GetAllStudent();//result 返回自定义的InvokeWebResult<T> 这里是分页返回的就是InvokeWebResult<PagedList<T>>
            return new JsonDataGridResult(result.Data);//没有了total  没有了 rows
        }
//result 是 InvokeWebResult<PagedList<T>> 具体的转换有JsonDataGridResult,内部实现。
//其实有MVC源码，里面有很多值得学习的