json序列化.xml序列化.图片转base64.base64转图片.生成缩略图.IEnumerable<TResult> Select<TSource, TResult>做数据转换的五种方式

 JSON序列化

    /// <summary>
    /// JSON序列化
    /// </summary>
    public  static class SPDBJsonConvert
    {
        /// <summary>
        /// 对象序列化JSON
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="t"></param>
        /// <returns></returns>
        public static string JsonSerializer<T>(T t)
        {
            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));
            MemoryStream ms = new MemoryStream();
            ser.WriteObject(ms, t);
            string jsonString = Encoding.UTF8.GetString(ms.ToArray());
            ms.Close();
            return jsonString;
        }
        /// <summary>
        /// JSON序列化对象
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="jsonString"></param>
        /// <returns></returns>
        public static T JsonDeserialize<T>(string jsonString)
        {
            DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(T));
            MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));
            T obj = (T)ser.ReadObject(ms);
            return obj;
        }
    }

 xml序列化

/// <summary>        

/// XML反序列化        

/// </summary>        

/// <param name="type">类型</param>        

/// <param name="xml">XML字符串</param>        

/// <returns></returns>        

public static object Deserialize(Type type, string xml)        

{            

try            

{                

using (StringReader sr = new StringReader(xml))                

{                    

XmlSerializer xmldes = new XmlSerializer(type);                   

  return xmldes.Deserialize(sr);         

        }        

     }         

    catch (Exception e)       

      {

                return null;     

        }      

   }

 /// <summary>      

 /// 序列化       

 /// </summary>  

 /// <param name="type">类型</param>        

/// <param name="obj">对象</param>        

/// <returns></returns>        

public static string Serializer(Type type, object obj)   

      {            

MemoryStream Stream = new MemoryStream();     

        XmlSerializer xml = new XmlSerializer(type);    

         try          

   {            

     //序列化对象         

        xml.Serialize(Stream, obj);     

        }         

    catch (InvalidOperationException)      

       {           

      throw;        

     }          

   Stream.Position = ;        

   StreamReader sr = new StreamReader(Stream);    

    string str = sr.ReadToEnd();

    sr.Dispose();    

    Stream.Dispose();

            return str;        

}

 图片转base64.base64转图片

/// <summary>        

/// 图片转base64        

/// </summary>        

/// <param name="filename"></param>        

public static string ImgToBase64String(string filename)        

{                

Bitmap bmp = new Bitmap(filename);

 MemoryStream ms = new MemoryStream();                

bmp.Save(ms, ImageFormat.Jpeg);                

byte[] arr = new byte[ms.Length];                

ms.Position = ;                

ms.Read(arr, , (int)ms.Length);                

ms.Close();                

String strbaser64 = Convert.ToBase64String(arr);          

   return strbaser64;       

  }

/// <summary>
        /// base64转图片
        /// </summary>
        /// <param name="base64Code"></param>
        public static Bitmap Base64StringToImage(string base64Code)
        {
                byte[] arr = Convert.FromBase64String(base64Code);
                MemoryStream ms = new MemoryStream(arr);
                Bitmap bmp = new Bitmap(ms);
                ms.Close();
            return bmp;
        }

 生成缩略图

/// <summary>       

  /// 生成缩略图        

/// </summary>        

/// <param name="img">原始图片</param>        

/// <param name="thumbnailImagePath">缩略图地址</param>        

/// <param name="width">图片宽度</param>        

/// <param name="height">图片高度</param>        

/// <param name="p"></param>        

public static void CutImage(Image img, string thumbnailImagePath, int width, int height)        

{           

  Image serverImage = img;            

//画板大小            

int towidth = width;         

    int toheight = height;        

     //缩略图矩形框的像素点       

      int x = ;         

    int y = ;          

   int ow = serverImage.Width;       

      int oh = serverImage.Height;

            if (ow > oh)         

    {             

    toheight = serverImage.Height * width / serverImage.Width;    

         }          

   else          

   {             

    towidth = serverImage.Width * height / serverImage.Height;   

          }       

      //新建一个bmp图片      

       Image bm = new Bitmap(width, height);      

       //新建一个画板          

   Graphics g = Graphics.FromImage(bm);   

          //设置高质量插值法     

        g.InterpolationMode = InterpolationMode.High;    

         //设置高质量,低速度呈现平滑程度     

        g.SmoothingMode = SmoothingMode.HighQuality;  

           //清空画布并以透明背景色填充        

     g.Clear(Color.White);         

    //在指定位置并且按指定大小绘制原图片的指定部分  

           g.DrawImage(serverImage, new Rectangle((width - towidth) / , (height - toheight) / , towidth, toheight),                 , , ow, oh,                 GraphicsUnit.Pixel);

            //以jpg格式保存缩略图      

       bm.Save(thumbnailImagePath, ImageFormat.Jpeg);  

           serverImage.Dispose();       

      bm.Dispose();       

      g.Dispose();      

   }

  很多时候很多状态数据库里可能都是保存的int。

                        但是在web上要转换成string.由于model要映射到数据库。

                              一般不能随意添加字段。所以在此提供一个方便的数据转换方法。

                                       至少不用写个循环去匹配每个字段

方式1

 List<EntityBM_CompanyDept> result = data.Select(ConvertBM_CompanyDept).ToList();

/// <summary>
        /// 数据转换
        /// </summary>
        /// <param name="model"></param>
        /// <returns></returns>
        [NonAction]
        protected virtual EntityBM_CompanyDept ConvertBM_CompanyDept(BM_CompanyDept model)
        {
            return new EntityBM_CompanyDept()
            {
                Id = model.Id,
                DeptId = model.DeptId,
                DeptName = model.DeptName,
                ParentDeptId = model.ParentDeptId,
                LevelCode = model.LevelCode,
                IsCostCenter = model.IsCostCenter,
                IsProfitCenter = model.IsProfitCenter,
                CompanyDeptStatus = model.CompanyDeptStatus,
                Result = ""
            };
        }

方式二

 List<EntityBM_CompanyDept> l = data.Select<BM_CompanyDept, EntityBM_CompanyDept>((dr) =>                   

  {                        

EntityBM_CompanyDept m = new EntityBM_CompanyDept()                

         {                             Id = dr.Id

//这里写转换字段

  };                      

   return m;               

      }).ToList<EntityBM_CompanyDept>();

方式三

      List<EntityBM_CompanyDept> l1 = data.Select((BM_CompanyDept) =>                     {                     

    EntityBM_CompanyDept m = new EntityBM_CompanyDept()                  

       {                             Id = BM_CompanyDept.Id,//转换字段

                        };                  

       return m;                 

    }).ToList<EntityBM_CompanyDept>();

　　方式四

 List<ExtraterritorialDataDto> rows = new List<ExtraterritorialDataDto>();

  if (rows != null)
                {
                    rows = rows.Select(a => new ExtraterritorialDataDto
                    {
                        Id = a.Id,//主键列
                        messagesubject = a.messagesubject,//主题
                        senderaddress = a.senderaddress,//发送者
                        Month = a.datetime.ToString(),//年月日
                        recipientaddress = a.recipientaddress//接受者
                    }).ToList();

                }

方式五

List<ExtraterritorialDataDto> rows = new List<ExtraterritorialDataDto>();

if (rows != null)
                {
                  var  rows2 = rows.Select(a => new
                    {
                        Id = a.Id,//主键列
                        messagesubject = a.messagesubject,//主题
                        senderaddress = a.senderaddress,//发送者
                        Month = a.datetime.ToString(),//年月日
                        recipientaddress = a.recipientaddress//接受者
                    }).ToList();

                }

方式四和方式五的差距在于一个是显式类型。一个是匿名类型