C#中把Datatable转换为Json的5个代码实例

/// <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>
    /// 格式化字符型、日期型、布尔型
    /// </summary>
    /// <param name="str"></param>
    /// <param name="type"></param>
    /// <returns></returns>
    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;
    }
    /// <summary>
    /// 过滤特殊字符
    /// </summary>
    /// <param name="s">字符串</param>
    /// <returns>json字符串</returns>
    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 '\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();
    }

   

 public static string createjsonparameters(datatable dt)
        {
            /**//**/
            /**//* /****************************************************************************
          * without goingin to the depth of the functioning of this method, i will try to give an overview
          * as soon as this method gets a datatable it starts to convert it into json string,
          * it takes each row and in each row it grabs the cell name and its data.
          * this kind of json is very usefull when developer have to have column name of the .
          * values can be access on clien in this way. obj.head[0].<columnname>
          * note: one negative point. by this method user will not be able to call any cell by its index.
         * *************************************************************************/
            stringbuilder jsonstring = new stringbuilder();
            //exception handling       
            if (dt != null && dt.rows.count > 0)
            {
                jsonstring.append("{ ");
                jsonstring.append("\"t_blog\":[ ");
                for (int i = 0; i < dt.rows.count; i++)
                {
                    jsonstring.append("{ ");
                    for (int j = 0; j < dt.columns.count; j++)
                    {
                        if (j < dt.columns.count - 1)
                        {
                            jsonstring.append("\"" + dt.columns[j].columnname.tostring() + "\":" + "\"" + dt.rows[i][j].tostring() + "\",");
                        }
                        else if (j == dt.columns.count - 1)
                        {
                            jsonstring.append("\"" + dt.columns[j].columnname.tostring() + "\":" + "\"" + dt.rows[i][j].tostring() + "\"");
                        }
                    }
                    /**//**/
                    /**//*end of string*/
                    if (i == dt.rows.count - 1)
                    {
                        jsonstring.append("} ");
                    }
                    else
                    {
                        jsonstring.append("}, ");
                    }
                }
                jsonstring.append("]}");
                return jsonstring.tostring();
            }
            else
            {
                return null;
            }
        }
 

/// <summary>
    /// 将一个数据表转换成一个json字符串，在客户端可以直接转换成二维数组。
    /// </summary>
    /// <param name="source">需要转换的表。</param>
    /// <returns></returns>
    public static string datatabletojson(datatable source)
    {
        if (source.rows.count == 0)
            return "";
        stringbuilder sb = new stringbuilder("[");
        foreach (datarow row in source.rows)
        {
            sb.append("[");
            for (int i = 0; i < source.columns.count; i++)
            {
                sb.append('"' + row[i].tostring() + "\",");
            }
            sb.remove(sb.length - 1, 1);
            sb.append("],");
        }
        sb.remove(sb.length - 1, 1);
        sb.append("]");
        return sb.tostring();
    }

    /// <summary>
    /// 反回json数据到前台
    /// </summary>
    /// <param name="dt">数据表</param>
    /// <returns>json字符串</returns>
    public string createjsonparameters(datatable dt)
    {
        stringbuilder jsonstring = new stringbuilder();
        //exception handling       
        if (dt != null && dt.rows.count > 0)
        {
            jsonstring.append("{ ");
            jsonstring.append("\"tableinfo\":[ ");
            for (int i = 0; i < dt.rows.count; i++)
            {
                jsonstring.append("{ ");
                for (int j = 0; j < dt.columns.count; j++)
                {
                    if (j < dt.columns.count - 1)
                    {
                        jsonstring.append("\"" + dt.columns[j].columnname.tostring() + "\":" + "\"" + dt.rows[i][j].tostring() + "\",");
                    }
                    else if (j == dt.columns.count - 1)
                    {
                        jsonstring.append("\"" + dt.columns[j].columnname.tostring() + "\":" + "\"" + dt.rows[i][j].tostring() + "\"");
                    }
                }
                /**/
                /*end of string*/
                if (i == dt.rows.count - 1)
                {
                    jsonstring.append("} ");
                }
                else
                {
                    jsonstring.append("}, ");
                }
            }
            jsonstring.append("]}");
            return jsonstring.tostring();
        }
        else
        {
            return null;
        }
    }

public class datatableconvertjson
    {

        #region datatable转换成json格式
        /// <summary> 
        /// datatable转换成json格式 
        /// </summary> 
        /// <param name="dt"></param> 
        /// <returns></returns> 
        public static string datatable2json(datatable dt)
        {
            stringbuilder jsonbuilder = new stringbuilder();
            jsonbuilder.append("{\"");
            jsonbuilder.append(dt.tablename);
            jsonbuilder.append("\":[");
            jsonbuilder.append("[");
            for (int i = 0; i < dt.rows.count; i++)
            {
                jsonbuilder.append("{");
                for (int j = 0; j < dt.columns.count; j++)
                {
                    jsonbuilder.append("\"");
                    jsonbuilder.append(dt.columns[j].columnname);
                    jsonbuilder.append("\":\"");
                    jsonbuilder.append(dt.rows[i][j].tostring());
                    jsonbuilder.append("\",");
                }
                jsonbuilder.remove(jsonbuilder.length - 1, 1);
                jsonbuilder.append("},");
            }
            jsonbuilder.remove(jsonbuilder.length - 1, 1);
            jsonbuilder.append("]");
            jsonbuilder.append("}");
            return jsonbuilder.tostring();
        }

        #endregion datatable转换成json格式
        #region dataset转换成json格式
        /// <summary> 
        /// dataset转换成json格式 
        /// </summary> 
        /// <param name="ds">dataset</param>
        /// <returns></returns> 
        public static string dataset2json(dataset ds)
        {
            stringbuilder json = new stringbuilder();

            foreach (datatable dt in ds.tables)
            {
                json.append("{\"");
                json.append(dt.tablename);
                json.append("\":");
                json.append(datatable2json(dt));
                json.append("}");
            } return json.tostring();
        }
        #endregion

        /// <summary>
        /// msdn
        /// </summary>
        /// <param name="jsonname"></param>
        /// <param name="dt"></param>
        /// <returns></returns>
        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();
        }
    }

#region  datatable 转换为json字符串实例方法
/// <summary>
/// getclasstypejosn 的摘要说明
/// </summary>
public class getclasstypejosn : ihttphandler
{
    /// <summary>
    /// 文件名:datatable 和json 字符串互转
    /// 版权所有:copyright (c) create family wealth liangjw
    /// 创建标示：2013-08-03
    /// </summary>
    //用法说明实例
     public void processrequest(httpcontext context)
    {
        context.response.contenttype = "application/json";
        context.response.charset = "utf-8";
        httprequest req = context.request;
        string method = req["method"].tostr().tolower();

       //获取合同明细列表  datatable 转换为json字符串
        if (method == "txtdate")
        {
            string json = "";
            bo.makecontractmx bll = new makecontractmx();
            dataset ds = bll.getdatatable();
            if (ds.tables.count > 0)
            {
                json =tojson(ds.tables[0]);
            }
            context.response.write(json);
            return;
        }

    }

   public bool isreusable
    {
        get
        {
            return false;
        }
    }
}

   #endregion

    #region json字符串转换为datatable 实例方法

    public datatable jsontodatatable(json)
    {
       datatable  dt= todatatable(json);
         return dt;
    }
   
   #endregion

    #region datatable 转换为json 字符串
    /// <summary>
    /// datatable 对象 转换为json 字符串
    /// </summary>
    /// <param name="dt"></param>
    /// <returns></returns>
    public static string tojson(this datatable dt)
    {
        javascriptserializer javascriptserializer = new javascriptserializer();
        javascriptserializer.maxjsonlength = int32.maxvalue; //取得最大数值
        arraylist arraylist = new arraylist();
        foreach (datarow datarow in dt.rows)
        {
            dictionary<string, object> dictionary = new dictionary<string, object>();  //实例化一个参数集合
            foreach (datacolumn datacolumn in dt.columns)
            {
                dictionary.add(datacolumn.columnname, datarow[datacolumn.columnname].tostr());
            }
            arraylist.add(dictionary); //arraylist集合中添加键值
        }

        return javascriptserializer.serialize(arraylist);  //返回一个json字符串
    }
    #endregion

    #region json 字符串 转换为 datatable数据集合
    /// <summary>
    /// json 字符串 转换为 datatable数据集合
    /// </summary>
    /// <param name="json"></param>
    /// <returns></returns>
    public static datatable todatatable(this string json)
    {
        datatable datatable = new datatable();  //实例化
        datatable result;
        try
        {
            javascriptserializer javascriptserializer = new javascriptserializer();
            javascriptserializer.maxjsonlength = int32.maxvalue; //取得最大数值
            arraylist arraylist = javascriptserializer.deserialize<arraylist>(json);
            if (arraylist.count > 0)
            {
                foreach (dictionary<string, object> dictionary in arraylist)
                {
                    if (dictionary.keys.count<string>() == 0)
                    {
                        result = datatable;
                        return result;
                    }
                    if (datatable.columns.count == 0)
                    {
                        foreach (string current in dictionary.keys)
                        {
                            datatable.columns.add(current, dictionary[current].gettype());
                        }
                    }
                    datarow datarow = datatable.newrow();
                    foreach (string current in dictionary.keys)
                    {
                        datarow[current] = dictionary[current];
                    }

                    datatable.rows.add(datarow); //循环添加行到datatable中
                }
            }
        }
        catch
        {
        }
        result = datatable;
        return result;
    }
    #endregion

    #region 转换为string字符串类型
    /// <summary>
    ///  转换为string字符串类型
    /// </summary>
    /// <param name="s">获取需要转换的值</param>
    /// <param name="format">需要格式化的位数</param>
    /// <returns>返回一个新的字符串</returns>
    public static string tostr(this object s, string format = "")
    {
        string result = "";
        try
        {
            if (format == "")
            {
                result = s.tostring();
            }
            else
            {
                result = string.format("{0:" + format + "}", s);
            }
        }
        catch
        {
        }
        return result;
    }
   #endregion