.NET(C#)中的DataSet、string、DataTable等对象转换成Json

ConvertJson.cs类

 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 = ; 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>
         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[];
             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[].GetType().Name;
             Json.Append("{\"" + jsonName + "\":[");
             if (list.Count > )
             {
                 for (int i = ; i < list.Count; i++)
                 {
                     T obj = Activator.CreateInstance<T>();
                     PropertyInfo[] pi = obj.GetType().GetProperties();
                     Json.Append("{");
                     for (int j = ; 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 - )
                         {
                             Json.Append(",");
                         }
                     }
                     Json.Append("}");
                     if (i < list.Count - )
                     {
                         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 = ; 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 - , 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 - , 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 - , 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 = ; i < drc.Count; i++)
             {
                 jsonString.Append("{");
                 for (int j = ; 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 - )
                     {
                         jsonString.Append(strValue + ",");
                     }
                     else
                     {
                         jsonString.Append(strValue);
                     }
                 }
                 jsonString.Append("},");
             }
             jsonString.Remove(jsonString.Length - , );
             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 > )
             {
                 for (int i = ; i < dt.Rows.Count; i++)
                 {
                     Json.Append("{");
                     for (int j = ; 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 - )
                         {
                             Json.Append(",");
                         }
                     }
                     Json.Append("}");
                     if (i < dt.Rows.Count - )
                     {
                         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 = ; 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 - )
                     {
                         jsonString.Append(strValue + ",");
                     }
                     else
                     {
                         jsonString.Append(strValue);
                     }
                 }
                 jsonString.Append("},");
             }
             dataReader.Close();
             jsonString.Remove(jsonString.Length - , );
             jsonString.Append("]");
             return jsonString.ToString();
         }
         #endregion
     }
 }

JsonHelper.cs类

 using System;
  using System.Collections.Generic;
  using System.Text;
  using System.Runtime.Serialization.Json;
  using System.IO;

  namespace DotNet.Utilities.Json
  {
      public class JsonHelper
      {
          /// <summary>
          /// 对象转为Json
          /// </summary>
          /// <param name="obj"></param>
          /// <returns></returns>
          public static string ObjectToJson(object obj)
          {
              DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
              using (MemoryStream stream = new MemoryStream())
              {
                  serializer.WriteObject(stream, obj);
                  return Encoding.UTF8.GetString(stream.ToArray());
              }
          }
         /// <summary>
         /// Json转为对象
         /// </summary>
         /// <param name="jsonString"></param>
         /// <param name="obj"></param>
         /// <returns></returns>
          public static object JsonToObject(string jsonString, object obj)
          {
              DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
              using (MemoryStream mStream = new MemoryStream(Encoding.UTF8.GetBytes(jsonString)))
              {
                  return serializer.ReadObject(mStream);
              }

          }
      /// <summary>
         /// JSON文本转对象,泛型方法
         /// </summary>
         /// <typeparam name="T">类型</typeparam>
         /// <param name="jsonText">JSON文本</param>
         /// <returns>指定类型的对象</returns>
         public static T JSONToObject<T>(string jsonText)
         {
             JavaScriptSerializer jss = new JavaScriptSerializer();
             try
             {
                 return jss.Deserialize<T>(jsonText);
             }
             catch (Exception ex)
             {
                 throw new Exception("JSONHelper.JSONToObject(): " + ex.Message);
             }
         }
      }
  }