C#转换成Json的方法集

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;
using System.Data;
using System.Reflection;
using System.Collections;
using System.Data.Common;

namespace Common
{
    //Json转化类
    public class ConvertToJson
    {
        #region 私有方法
        private static string StringToJson(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 '':
                        sb.Append("\b");
                        break;
                    case 'f':
                        sb.Append("\f");
                        break;
                    case'
':
                        sb.Append("\n");
                        break;
                    case '
':
                        sb.Append("\r");
                        break;
                    case '	':
                        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 = StringToJson(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转化成Json
        public static string ListToJson<T>(IList<T> list)
        {
            object obj = list[0];
            return ListToJson<T>(list, obj.GetType().Name);
        }

        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 < pi.Length - 1)
                    {
                        Json.Append(",");
                    }
                }
            }
            Json.Append("]}");
            return Json.ToString();
        }

        #endregion

        #region  对象转换为Json
        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Json
        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  普通集合转换为Json
        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Json
        public static string ToJson(DataSet dataSet)
        {
            string jsonString = "[";
            foreach(DataTable table in dataSet.Tables)
            {
                jsonString += """+table.TableName+"":"+ToJson(table)+",";

            }
            jsonString = jsonString.TrimEnd(',');
            return jsonString + "]";
        }

        /// <summary>
        /// DataTable转换为Json
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></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,jsonString.Length);
            jsonString.Append("]");
            return jsonString.ToString();
        }

        /// <summary>
        /// DataTable转换为Json
        /// </summary>
        /// <param name="dt"></param>
        /// <param name="jsonName"></param>
        /// <returns></returns>
        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(i<dt.Rows.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
        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,jsonString.Length);
            jsonString.Append("]");
            return jsonString.ToString();
        }
        #endregion

    }
}