C#中的DataSet、string、DataTable 、对象转换成Json

C#中对象，字符串，dataTable、DataReader、DataSet，对象集合转换成Json字符串方法。

public  class ConvertJson
    {
         #region 私有方法
         ///   <summary>
         ///  过滤特殊字符
         ///   </summary>
         ///   <param name="s"> 字符串 </param>
         ///   <returns> json字符串 </returns>
         private  static  string String2Json(String s)
        {
            StringBuilder sb =  new StringBuilder();
             for ( int i =  0; i < s.Length; i++)
            {
                 char c = s.ToCharArray()[i];
                 switch (c)
                {
                     case  ' \" ':
                        sb.Append( " \\\" ");  break;
                     case  ' \\ ':
                        sb.Append( " \\\\ ");  break;
                     case  ' / ':
                        sb.Append( " \\/ ");  break;
                     case  ' \b ':
                        sb.Append( " \\b ");  break;
                     case  ' \f ':
                        sb.Append( " \\f ");  break;
                     case  ' \n ':
                        sb.Append( " \\n ");  break;
                     case  ' \r ':
                        sb.Append( " \\r ");  break;
                     case  ' \t ':
                        sb.Append( " \\t ");  break;
                     default:
                        sb.Append(c);  break;
                }
            }
             return sb.ToString();
        }
         ///   <summary>
         ///  格式化字符型、日期型、布尔型
         ///   </summary>
         ///   <param name="str"></param>
         ///   <param name="type"></param>
         ///   <returns></returns>
         private  static  string StringFormat( string str, Type type)
        {
             if (type ==  typeof( string))
            {
                str = String2Json(str);
                str =  " \" " + str +  " \" ";
            }
             else  if (type ==  typeof(DateTime))
            {
                str =  " \" " + str +  " \" ";
            }
             else  if (type ==  typeof( bool))
            {
                str = str.ToLower();
            }
             else  if (type !=  typeof( string) &&  string.IsNullOrEmpty(str))
            {
                str =  " \" " + str +  " \" ";
            }
             return str;
        }

         #endregion

         #region list转换成JSON
         ///   <summary>
         ///  list转换为Json
         ///   </summary>
         ///   <typeparam name="T"></typeparam>
         ///   <param name="list"></param>
         ///   <returns></returns>
         public  static  string ListToJson<T>(IList<T> list)
        {
             object obj = list[ 0];
             return ListToJson<T>(list, obj.GetType().Name);
        }
         ///   <summary>
         ///  list转换为json
         ///   </summary>
         ///   <typeparam name="T1"></typeparam>
         ///   <param name="list"></param>
         ///   <param name="p"></param>
         ///   <returns></returns>
         private  static  string ListToJson<T>(IList<T> list,  string JsonName)
        {
            StringBuilder Json =  new StringBuilder();
             if ( string.IsNullOrEmpty(JsonName))
                JsonName = list[ 0].GetType().Name;
            Json.Append( " {\" " + JsonName +  " \":[ ");
             if (list.Count >  0)
            {
                 for ( int i =  0; i < list.Count; i++)
                {
                    T obj = Activator.CreateInstance<T>();
                    PropertyInfo[] pi = obj.GetType().GetProperties();
                    Json.Append( " { ");
                     for ( int j =  0; j < pi.Length; j++)
                    {
                        Type type = pi[j].GetValue(list[i],  null).GetType();
                        Json.Append( " \" " + pi[j].Name.ToString() +  " \": " + StringFormat(pi[j].GetValue(list[i],  null).ToString(), type));
                         if (j < pi.Length -  1)
                        {
                            Json.Append( " , ");
                        }
                    }
                    Json.Append( " } ");
                     if (i < list.Count -  1)
                    {
                        Json.Append( " , ");
                    }
                }
            }
            Json.Append( " ]} ");
             return Json.ToString();
        }
         #endregion

         #region 对象转换为Json
         ///   <summary>
         ///  对象转换为json
         ///   </summary>
         ///   <param name="jsonObject"> json对象 </param>
         ///   <returns> json字符串 </returns>
         public  static  string ToJson( object jsonObject)
        {
             string jsonString =  " { ";
            PropertyInfo[] propertyInfo = jsonObject.GetType().GetProperties();
             for ( int i =  0; i < propertyInfo.Length; i++)
            {
                 object objectValue = propertyInfo[i].GetGetMethod().Invoke(jsonObject,  null);
                 string value =  string.Empty;
                 if (objectValue  is DateTime || objectValue  is Guid || objectValue  is TimeSpan)
                {
                    value =  " ' " + objectValue.ToString() +  " ' ";
                }
                 else  if (objectValue  is  string)
                {
                    value =  " ' " + ToJson(objectValue.ToString()) +  " ' ";
                }
                 else  if (objectValue  is IEnumerable)
                {
                    value = ToJson((IEnumerable)objectValue);
                }
                 else
                {
                    value = ToJson(objectValue.ToString());
                }
                jsonString +=  " \" " + ToJson(propertyInfo[i].Name) +  " \": " + value +  " , ";
            }
            jsonString.Remove(jsonString.Length -  1, jsonString.Length);
             return jsonString +  " } ";
        }

         #endregion

         #region 对象集合转换为json
         ///   <summary>
         ///  对象集合转换为json
         ///   </summary>
         ///   <param name="array"> 对象集合 </param>
         ///   <returns> json字符串 </returns>
         public  static  string ToJson(IEnumerable array)
        {
             string jsonString =  " { ";
             foreach ( object item  in array)
            {
                jsonString += ToJson(item) +  " , ";
            }
            jsonString.Remove(jsonString.Length -  1, jsonString.Length);
             return jsonString +  " ] ";
        }
         #endregion

         #region 普通集合转换Json
         ///   <summary>     
         ///  普通集合转换Json   
         ///   </summary>    
         ///   <param name="array"> 集合对象 </param>  
         ///   <returns> Json字符串 </returns>   
         public  static  string ToArrayString(IEnumerable array)
        {
             string jsonString =  " [ ";
             foreach ( object item  in array)
            {
                jsonString = ToJson(item.ToString()) +  " , ";
            }
            jsonString.Remove(jsonString.Length -  1, jsonString.Length);
             return jsonString +  " ] ";
        }
         #endregion

         #region  DataSet转换为Json
         ///   <summary>     
         ///  DataSet转换为Json   
         ///   </summary>     
         ///   <param name="dataSet"> DataSet对象 </param>    
         ///   <returns> Json字符串 </returns>     
         public  static  string ToJson(DataSet dataSet)
        {
             string jsonString =  " { ";
             foreach (DataTable table  in dataSet.Tables)
            {
                jsonString +=  " \" " + table.TableName +  " \": " + ToJson(table) +  " , ";
            }
            jsonString = jsonString.TrimEnd( ' , ');
             return jsonString +  " } ";
        }
         #endregion

         #region Datatable转换为Json
         ///   <summary>      
         ///  Datatable转换为Json     
         ///   </summary>     
         ///   <param name="table"> Datatable对象 </param>      
         ///   <returns> Json字符串 </returns>      
         public  static  string ToJson(DataTable dt)
        {
            StringBuilder jsonString =  new StringBuilder();
            jsonString.Append( " [ ");
            DataRowCollection drc = dt.Rows;
             for ( int i =  0; i < drc.Count; i++)
            {
                jsonString.Append( " { ");
                 for ( int j =  0; j < dt.Columns.Count; j++)
                {
                     string strKey = dt.Columns[j].ColumnName;
                     string strValue = drc[i][j].ToString();
                    Type type = dt.Columns[j].DataType;
                    jsonString.Append( " \" " + strKey +  " \": ");
                    strValue = StringFormat(strValue, type);
                     if (j < dt.Columns.Count -  1)
                    {
                        jsonString.Append(strValue +  " , ");
                    }
                     else
                    {
                        jsonString.Append(strValue);
                    }
                }
                jsonString.Append( " }, ");
            }
            jsonString.Remove(jsonString.Length -  1,  1);
            jsonString.Append( " ] ");
             return jsonString.ToString();
        }
         ///   <summary>     
         ///  DataTable转换为Json     
         ///   </summary>     
         public  static  string ToJson(DataTable dt,  string jsonName)
        {
            StringBuilder Json =  new StringBuilder();
             if ( string.IsNullOrEmpty(jsonName))
                jsonName = dt.TableName;
            Json.Append( " {\" " + jsonName +  " \":[ ");
             if (dt.Rows.Count >  0)
            {
                 for ( int i =  0; i < dt.Rows.Count; i++)
                {
                    Json.Append( " { ");
                     for ( int j =  0; j < dt.Columns.Count; j++)
                    {
                        Type type = dt.Rows[i][j].GetType();
                        Json.Append( " \" " + dt.Columns[j].ColumnName.ToString() +  " \": " + StringFormat(dt.Rows[i][j].ToString(), type));
                         if (j < dt.Columns.Count -  1)
                        {
                            Json.Append( " , ");
                        }
                    }
                    Json.Append( " } ");
                     if (i < dt.Rows.Count -  1)
                    {
                        Json.Append( " , ");
                    }
                }
            }
            Json.Append( " ]} ");
             return Json.ToString();
        }

         #endregion

         #region DataReader转换为Json
         ///   <summary>      
         ///  DataReader转换为Json     
         ///   </summary>      
         ///   <param name="dataReader"> DataReader对象 </param>      
         ///   <returns> Json字符串 </returns>   
         public  static  string ToJson(DbDataReader dataReader)
        {
            StringBuilder jsonString =  new StringBuilder();
            jsonString.Append( " [ ");
             while (dataReader.Read())
            {
                jsonString.Append( " { ");
                 for ( int i =  0; i < dataReader.FieldCount; i++)
                {
                    Type type = dataReader.GetFieldType(i);
                     string strKey = dataReader.GetName(i);
                     string strValue = dataReader[i].ToString();
                    jsonString.Append( " \" " + strKey +  " \": ");
                    strValue = StringFormat(strValue, type);
                     if (i < dataReader.FieldCount -  1)
                    {
                        jsonString.Append(strValue +  " , ");
                    }
                     else
                    {
                        jsonString.Append(strValue);
                    }
                }
                jsonString.Append( " }, ");
            }
            dataReader.Close();
            jsonString.Remove(jsonString.Length -  1,  1);
            jsonString.Append( " ] ");
             return jsonString.ToString();
        }
         #endregion

    }