asp.net 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("[");
        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("},");
        }
        if (dt.Rows.Count > 0)
        {
            jsonBuilder.Remove(jsonBuilder.Length - 1, 1);
        }
        jsonBuilder.Append("]");
        return jsonBuilder.ToString();
    }