json转换（c#后台生成json的方法）

此文转自：http://bbs.csdn.net/topics/380200497，为了方便自己记忆才以文章形式保存。

using System;

using System.Collections.Generic;

using System.Text;

using System.Data;

using System.Reflection;

using System.Collections;

using System.Data.Common;

 

namespace DotNet.Utilities

{

    //JSON转换类

    public class ConvertJson

    {

        #region 私有方法

        /// <summary>

        /// 过滤特殊字符

        /// </summary>

        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 '':

                        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>

        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转换成Json

        /// </summary>

        public static string ListToJson<T>(IList<T> list)

        {

            object obj = list[0];

            return ListToJson<T>(list, obj.GetType().Name);

        }

 

        /// <summary>

        /// List转换成Json 

        /// </summary>

        public 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">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Json

        /// <summary> 

        /// 对象集合转换Json 

        /// </summary> 

        /// <param name="array">集合对象</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

    }

}