C#实现简单的JSON序列化

   好久没有做web了，JSON目前比较流行，闲得没事，所以动手试试将对象序列化为JSON字符（尽管DotNet Framework已经有现成的库，也有比较好的第三方开源库）,而且只是实现了处理简单的类型,并且DateTime处理的也不专业，有兴趣的筒子可以扩展，代码比较简单，反序列化木有实现:( ，直接贴代码吧，都有注释了，所以废话不多说  :)

 

测试类

///   <summary>
     ///  Nested class of Person.
     ///   </summary>
     public   class  House
    {
         public   string  Name
        {
             get ;
             set ;
        }
         public   double  Price
        {
             get ;
             set ;
        }
    }

     ///   <summary>
     ///  Person dummy class
     ///   </summary>
     public   class  Person
    {
         public   string  Name
        {
             get ;
             set ;
        }
         public   int  Age
        {
             get ;
             set ;
        }
         public   string  Address
        {
             get ;
             set ;
        }
         private   int  h  =   12 ;

         public   bool  IsMarried
        {
             get ;
             set ;
        }

         public   string [] Names
        {
             get ;
             set ;
        }

         public   int [] Ages
        {
             get ;
             set ;
        }
         public  House MyHouse
        {
             get ;
             set ;
        }
         public  DateTime BirthDay
        {
             get ;
             set ;
        }
         public  List < string >  Friends
        {
             get ;
             set ;
        }
         public  List < int >  LoveNumbers
        {
             get ;
             set ;
        }
    }

 

接口定义

   ///   <summary>
     ///  IJsonSerializer interface.
     ///   </summary>
     interface  IJsonSerializer
    {
         ///   <summary>
         ///  Serialize object to json string.
         ///   </summary>
         ///   <typeparam name="T"> The type to be serialized. </typeparam>
         ///   <param name="obj"> Instance of the type T. </param>
         ///   <returns> json string. </returns>
         string  Serialize( object  obj);

         ///   <summary>
         ///  Deserialize json string to object.
         ///   </summary>
         ///   <typeparam name="T"> The type to be deserialized. </typeparam>
         ///   <param name="jsonString"> json string. </param>
         ///   <returns> instance of type T. </returns>
        T Deserialize < T > ( string  jsonString);
    }

 

接口实现，还有待完善..

///   <summary>
     ///  Implement IJsonSerializer, but Deserialize had not been implemented.
     ///   </summary>
     public   class  JsonSerializer : IJsonSerializer
    {
         ///   <summary>
         ///  Serialize object to json string.
         ///   </summary>
         ///   <typeparam name="T"> The type to be serialized. </typeparam>
         ///   <param name="obj"> Instance of the type T. </param>
         ///   <returns> json string. </returns>
         public   string  Serialize( object  obj)
        {
             if  (obj  ==   null )
            {
                 return   " {} " ;
            }

             //  Get the type of obj.
            Type t  =  obj.GetType();

             //  Just deal with the public instance properties. others ignored.
            BindingFlags bf  =  BindingFlags.Instance  |  BindingFlags.Public;

            PropertyInfo[] pis  =  t.GetProperties(bf);

            StringBuilder json  =   new  StringBuilder( " { " );

             if  (pis  !=   null   &&  pis.Length  >   0 )
            {
                 int  i  =   0 ;
                 int  lastIndex  =  pis.Length  -   1 ;

                 foreach  (PropertyInfo p  in  pis)
                {
                     //  Simple string
                     if  (p.PropertyType.Equals( typeof ( string )))
                    {
                        json.AppendFormat( " \"{0}\":\"{1}\" " , p.Name, p.GetValue(obj,  null ));
                    }
                     //  Number,boolean.
                     else   if  (p.PropertyType.Equals( typeof ( int ))  ||
                        p.PropertyType.Equals( typeof ( bool ))  ||
                        p.PropertyType.Equals( typeof ( double ))  ||
                        p.PropertyType.Equals( typeof ( decimal ))
                        )
                    {
                        json.AppendFormat( " \"{0}\":{1} " , p.Name, p.GetValue(obj,  null ).ToString().ToLower());
                    }
                     //  Array.
                     else   if  (isArrayType(p.PropertyType))
                    {
                         //  Array case.
                         object  o  =  p.GetValue(obj,  null );

                         if  (o  ==   null )
                        {
                            json.AppendFormat( " \"{0}\":{1} " , p.Name,  " null " );
                        }
                         else
                        {
                            json.AppendFormat( " \"{0}\":{1} " , p.Name, getArrayValue((Array)p.GetValue(obj,  null )));
                        }
                    }
                     //  Class type. custom class, list collections and so forth.
                     else   if  (isCustomClassType(p.PropertyType))
                    {
                         object  v  =  p.GetValue(obj,  null );
                         if  (v  is  IList)
                        {
                            IList il  =  v  as  IList;
                             string  subJsString  =  getIListValue(il);

                            json.AppendFormat( " \"{0}\":{1} " , p.Name, subJsString);
                        }
                         else
                        {
                             //  Normal class type.
                             string  subJsString  =  Serialize(p.GetValue(obj,  null ));

                            json.AppendFormat( " \"{0}\":{1} " , p.Name, subJsString);
                        }
                    }
                     //  Datetime
                     else   if  (p.PropertyType.Equals( typeof (DateTime)))
                    {
                        DateTime dt  =  (DateTime)p.GetValue(obj,  null );

                         if  (dt  ==   default (DateTime))
                        {
                            json.AppendFormat( " \"{0}\":\"\" " , p.Name);
                        }
                         else
                        {
                            json.AppendFormat( " \"{0}\":\"{1}\" " , p.Name, ((DateTime)p.GetValue(obj,  null )).ToString( " yyyy-MM-dd HH:mm:ss " ));
                        }
                    }
                     else
                    {
                         //  TODO: extend.
                    }

                     if  (i  >=   0   &&  i  !=  lastIndex)
                    {
                        json.Append( " , " );
                    }

                     ++ i;
                }
            }

            json.Append( " } " );

             return  json.ToString();
        }

         ///   <summary>
         ///  Deserialize json string to object.
         ///   </summary>
         ///   <typeparam name="T"> The type to be deserialized. </typeparam>
         ///   <param name="jsonString"> json string. </param>
         ///   <returns> instance of type T. </returns>
         public  T Deserialize < T > ( string  jsonString)
        {
             throw   new  NotImplementedException( " Not implemented :( " );
        }

         ///   <summary>
         ///  Get array json format string value.
         ///   </summary>
         ///   <param name="obj"> array object </param>
         ///   <returns> js format array string. </returns>
         string  getArrayValue(Array obj)
        {
             if  (obj  !=   null )
            {
                 if  (obj.Length  ==   0 )
                {
                     return   " [] " ;
                }

                 object  firstElement  =  obj.GetValue( 0 );
                Type et  =  firstElement.GetType();
                 bool  quotable  =  et  ==   typeof ( string );

                StringBuilder sb  =   new  StringBuilder( " [ " );
                 int  index  =   0 ;
                 int  lastIndex  =  obj.Length  -   1 ;

                 if  (quotable)
                {
                     foreach  (var item  in  obj)
                    {
                        sb.AppendFormat( " \"{0}\" " , item.ToString());

                         if  (index  >=   0   &&  index  !=  lastIndex)
                        {
                            sb.Append( " , " );
                        }

                         ++ index;
                    }
                }
                 else
                {
                     foreach  (var item  in  obj)
                    {
                        sb.Append(item.ToString());

                         if  (index  >=   0   &&  index  !=  lastIndex)
                        {
                            sb.Append( " , " );
                        }

                         ++ index;
                    }
                }

                sb.Append( " ] " );

                 return  sb.ToString();
            }

             return   " null " ;
        }

         ///   <summary>
         ///  Get Ilist json format string value.
         ///   </summary>
         ///   <param name="obj"> IList object </param>
         ///   <returns> js format IList string. </returns>
         string  getIListValue(IList obj)
        {
             if  (obj  !=   null )
            {
                 if  (obj.Count  ==   0 )
                {
                     return   " [] " ;
                }

                 object  firstElement  =  obj[ 0 ];
                Type et  =  firstElement.GetType();
                 bool  quotable  =  et  ==   typeof ( string );

                StringBuilder sb  =   new  StringBuilder( " [ " );
                 int  index  =   0 ;
                 int  lastIndex  =  obj.Count  -   1 ;

                 if  (quotable)
                {
                     foreach  (var item  in  obj)
                    {
                        sb.AppendFormat( " \"{0}\" " , item.ToString());

                         if  (index  >=   0   &&  index  !=  lastIndex)
                        {
                            sb.Append( " , " );
                        }

                         ++ index;
                    }
                }
                 else
                {
                     foreach  (var item  in  obj)
                    {
                        sb.Append(item.ToString());

                         if  (index  >=   0   &&  index  !=  lastIndex)
                        {
                            sb.Append( " , " );
                        }

                         ++ index;
                    }
                }

                sb.Append( " ] " );

                 return  sb.ToString();
            }

             return   " null " ;
        }

         ///   <summary>
         ///  Check whether t is array type.
         ///   </summary>
         ///   <param name="t"></param>
         ///   <returns></returns>
         bool  isArrayType(Type t)
        {
             if  (t  !=   null )
            {
                 return  t.IsArray;
            }

             return   false ;
        }

         ///   <summary>
         ///  Check whether t is custom class type.
         ///   </summary>
         ///   <param name="t"></param>
         ///   <returns></returns>
         bool  isCustomClassType(Type t)
        {
             if  (t  !=   null )
            {
                 return  t.IsClass  &&  t  !=   typeof ( string );
            }

             return   false ;
        }
    }

 

测试代码：

  class  Program
    {
         static   void  Main( string [] args)
        {
            Person ps  =   new  Person()
            {
                Name  =   " Leon " ,
                Age  =   25 ,
                Address  =   " China " ,
                IsMarried  =   false ,
                Names  =   new   string [] {  " wgc " ,  " leon " ,  " giantfish "  },
                Ages  =   new   int [] {  1 ,  2 ,  3 ,  4  },
                MyHouse  =   new  House()
                {
                    Name  =   " HouseName " ,
                    Price  =   100.01 ,
                },
                BirthDay  =   new  DateTime( 1986 ,  12 ,  20 ,  12 ,  12 ,  10 ),
                Friends  =   new  List < string > () {  " friend1 " ,  " friend2 "  },
                LoveNumbers  =   new  List < int > () {  1 ,  2 ,  3  }
            };

            IJsonSerializer js  =   new  JsonSerializer();
             string  s  =  js.Serialize(ps);
            Console.WriteLine(s);
            Console.ReadKey();
        }
    }

 

 生成的 JSON字符串 ：

{ " Name " : " Leon " , " Age " : 25 , " Address " : " China " , " IsMarried " : false , " Names " :[ " wgc " , " leon " , " giantfish " ], " Ages " :[ 1 , 2 , 3 , 4 ], " MyHouse " :{ " Name " : " HouseName " , " Price " : 100.01 }, " BirthDay " : " 1986-12-20 12:12:10 " , " Friends " :[ " friend1 " , " friend2 " ], " LoveNumbers " :[ 1 , 2 , 3 ]}

 

 嗯 ，就这样子，没有研究开源的JSON代码是如何实现的，应该也是拼接字符串吧，上面的代码再多测试，完善下，应该也差不多可以投产了 :)