C# DataTable,List和Json转换 C#实现DataTable,List和Json转换的方法

using System;
using System.Data;
using System.Text;
using System.Collections.Generic;
using System.Reflection;
/// <summary>
/// 将DataTable或Ilist<>转换成JSON格式
/// </summary>
public class ToJson
{
  public ToJson()
  {
  }
//DataTable转成Json
  public static string DataTableToJson(string jsonName, DataTable dt)
  {
    StringBuilder Json = new StringBuilder();
    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++)
        {
          Json.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":\"" + dt.Rows[i][j].ToString() + "\"");
          if (j < dt.Columns.Count - 1)
          {
            Json.Append(",");
          }
        }
        Json.Append("}");
        if (i < dt.Rows.Count - 1)
        {
          Json.Append(",");
        }
      }
    }
    Json.Append("]}");
    return Json.ToString();
  }
//List转成json
  public static string ObjectToJson<T>(string jsonName, IList<T> IL)
  {
    StringBuilder Json = new StringBuilder();
    Json.Append("{\"" + jsonName + "\":[");
    if (IL.Count > 0)
    {
      for (int i = 0; i < IL.Count; i++)
      {
        T obj = Activator.CreateInstance<T>();
        Type type = obj.GetType();
        PropertyInfo[] pis = type.GetProperties();
        Json.Append("{");
        for (int j = 0; j < pis.Length; j++)
        {
          Json.Append("\"" + pis[j].Name.ToString() + "\":\"" + pis[j].GetValue(IL[i], null) + "\"");
          if (j < pis.Length - 1)
          {
            Json.Append(",");
          }
        }
        Json.Append("}");
        if (i < IL.Count - 1)
        {
          Json.Append(",");
        }
      }
    }
    Json.Append("]}");
    return Json.ToString();
  }
}

/// <summary>
/// 对象转换为Json字符串
/// </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 + ",";
  }
  return Json.DeleteLast(jsonString) + "}";
}
/// <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 += Json.ToJson(item) + ",";
  }
  return Json.DeleteLast(jsonString) + "]";
}
/// <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()) + ",";
  }
  return Json.DeleteLast(jsonString) + "]";
}
/// <summary>
/// 删除结尾字符
/// </summary>
/// <param name="str">需要删除的字符</param>
/// <returns>完成后的字符串</returns>
private static string DeleteLast(string str)
{
  if (str.Length > 1)
  {
    return str.Substring(0, str.Length - 1);
  }
  return str;
}
/// <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 table)
{
  string jsonString = "[";
  DataRowCollection drc = table.Rows;
  for (int i = 0; i < drc.Count; i++)
  {
    jsonString += "{";
    foreach (DataColumn column in table.Columns)
    {
      jsonString += "\"" + ToJson(column.ColumnName) + "\":";
      if (column.DataType == typeof(DateTime) || column.DataType == typeof(string))
      {
        jsonString += "\"" + ToJson(drc[i][column.ColumnName].ToString()) + "\",";
      }
      else
      {
        jsonString += ToJson(drc[i][column.ColumnName].ToString()) + ",";
      }
    }
    jsonString = DeleteLast(jsonString) + "},";
  }
  return DeleteLast(jsonString) + "]";
}
/// <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)
{
  string jsonString = "[";
  while (dataReader.Read())
  {
    jsonString += "{";
    for (int i = 0; i < dataReader.FieldCount; i++)
    {
      jsonString += "\"" + ToJson(dataReader.GetName(i)) + "\":";
      if (dataReader.GetFieldType(i) == typeof(DateTime) || dataReader.GetFieldType(i) == typeof(string))
      {
        jsonString += "\"" + ToJson(dataReader[i].ToString()) + "\",";
      }
      else
      {
        jsonString += ToJson(dataReader[i].ToString()) + ",";
      }
    }
    jsonString = DeleteLast(jsonString) + "}";
  }
  dataReader.Close();
  return DeleteLast(jsonString) + "]";
}
/// <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 += "\"" + ToJson(table.TableName) + "\":" + ToJson(table) + ",";
  }
  return jsonString = DeleteLast(jsonString) + "}";
}
/// <summary>
/// String转换为Json
/// </summary>
/// <param name="value">String对象</param>
/// <returns>Json字符串</returns>
public static string ToJson(string value)
{
  if (string.IsNullOrEmpty(value))
  {
    return string.Empty;
  }
  string temstr;
  temstr = value;
  temstr = temstr.Replace("{", "｛").Replace("}", "｝").Replace(":", "：").Replace(",", "，").Replace("[", "【").Replace("]", "】").Replace(";", "；").Replace("\n", "<br/>").Replace("\r", "");
  temstr = temstr.Replace("\t", "  ");
  temstr = temstr.Replace("'", "\'");
  temstr = temstr.Replace(@"\", @"\\");
  temstr = temstr.Replace("\"", "\"\"");
  return temstr;
}