C#封装的一个JSON操作类

• using System;
  using System.Collections.Generic;
  using System.Collections;
  using System.Text;
  using System.Data;
  using System.Reflection;
  using System.Data.Common;
  
  namespace ZGZY.Common
  {
      /// <summary>
      /// JSON帮助类
      /// </summary>
      public class JsonHelper
      {
          #region 通用方法
          /// <summary>
          /// 格式化字符型、日期型、布尔型
          /// </summary>
          public static string StringFormat(string str, Type type)
          {
              if (type == typeof(string))
              {
                  str = StringFilter(str);
                  str = """ + str + """;
              }
              else if (type == typeof(DateTime) || type == typeof(DateTime?))
              {
                  str = """ + str + """;
              }
              else if (type == typeof(bool))
              {
                  str = str.ToLower();
              }
              else if (type == typeof(Guid))
              {
                  str = """ + str + """;
              }
              else if (type != typeof(string) && string.IsNullOrEmpty(str))
              {
                  str = """ + str + """;
              }
              return str;
          }
  
          /// <summary>
          /// 过滤字符串
          /// </summary>
          public static string StringFilter(string str)
          {
              StringBuilder sb = new StringBuilder();
              for (int i = 0; i < str.Length; i++)
              {
                  char c = str.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();
          }
          #endregion
  
          #region 列转json
          /// <summary>
          /// 列转json
          /// </summary>
          /// <param name="dt">表</param>
          /// <param name="r">列</param>
          public static string ColumnToJson(DataTable dt, int r)
          {
              StringBuilder strSql = new StringBuilder();
              for (int i = 0; i < dt.Rows.Count; i++)
              {
                  strSql.Append(dt.Rows[i][r]);
                  strSql.Append(",");
              }
              return strSql.ToString().Trim(',');
          }
          #endregion
  
          #region 对象转json
          /// <summary>
          /// 对象转json
          /// </summary>
          public static string ToJson(object jsonObject)
          {
              StringBuilder sb = new StringBuilder();
              sb.Append("{");
              PropertyInfo[] propertyInfo = jsonObject.GetType().GetProperties();
              for (int i = 0; i < propertyInfo.Length; i++)
              {
                  object objectValue = propertyInfo[i].GetGetMethod().Invoke(jsonObject, null);
                  Type type = propertyInfo[i].PropertyType;
                  string strValue = objectValue.ToString();
                  strValue = StringFormat(strValue, type);
                  sb.Append(""" + propertyInfo[i].Name + "":");
                  sb.Append(strValue + ",");
              }
              sb.Remove(sb.Length - 1, 1);
              sb.Append("}");
              return sb.ToString();
          }
          #endregion
  
          #region list转json
          /// <summary>
          /// list转json
          /// </summary>
          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 < list.Count - 1)
                      {
                          Json.Append(",");
                      }
                  }
              }
              Json.Append("]}");
              return Json.ToString();
          }
          #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 = jsonString.Substring(0, jsonString.Length - 1);
              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>    
          public static string ToJson(DataTable dt)
          {
              if (dt.Rows.Count > 0)
              {
                  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();
              }
              else
                  return "[]";
          }
  
          /// <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
  
  
          #region 返回错误
          public static string error()
          {
              DataTable dt = new DataTable();
              dt.Columns.Add("error", typeof(int));
              DataRow dr = dt.NewRow();
              dr["error"] = 1;
              dt.Rows.Add(dr);
              return ToJson(dt);
          }
          #endregion
  
      }
  }