C#实现DataTable,List和Json转换的方法

本文实例讲述了c#实现datatable,list和json转换的方法。分享给大家供大家参考，具体如下：

1. 将datatable或ilist<>转换成json格式

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();
  }
}

2. 各种数据集转换为json

/// <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;
}

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