用C#, 把从ONENET获取的JSON字符泛型转换为DataTable类型, 并导出至Excel

文件名: getJson_2List2Datatable_toExcel

功能: 将请求返回的JSON字符串解析并导入excel表格

一..构建解析json字符串的实体类

根据自己的json字符串构建实体类, 二这个类中存在着泛型

json字符串转c#实体类网址: https://www.bejson.com/convert/json2csharp/

//实体类, Datastreams的类模板
    public class DataItem
    {
        /// <summary>
        /// 
        /// </summary>
        public string create_time { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string update_at { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string id { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string uuid { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public int current_value { get; set; }
    }

    public class Root
    {
        /// <summary>
        /// 
        /// </summary>
        public int errno { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public List<DataItem> data { get; set; }
        /// <summary>
        /// 
        /// </summary>
        public string error { get; set; }
    }

二..将list<>泛型转换为Datatable类型数据

 //list2datatable
    public class ListToDatatable
    {
        public ListToDatatable() { }
        public static DataTable ListToDataTable<T>(List<T> entitys)
        {

            //检查实体集合不能为空
            if (entitys == null || entitys.Count < 1)
            {
                return new DataTable();
            }

            //取出第一个实体的所有Propertie
            Type entityType = entitys[0].GetType();
            PropertyInfo[] entityProperties = entityType.GetProperties();

            //生成DataTable的structure
            //生产代码中，应将生成的DataTable结构Cache起来，此处略
            DataTable dt = new DataTable("dt");
            for (int i = 0; i < entityProperties.Length; i++)
            {
                //dt.Columns.Add(entityProperties[i].Name, entityProperties[i].PropertyType);
                dt.Columns.Add(entityProperties[i].Name);
            }

            //将所有entity添加到DataTable中
            foreach (object entity in entitys)
            {
                //检查所有的的实体都为同一类型
                if (entity.GetType() != entityType)
                {
                    throw new Exception("要转换的集合元素类型不一致");
                }
                object[] entityValues = new object[entityProperties.Length];
                for (int i = 0; i < entityProperties.Length; i++)
                {
                    entityValues[i] = entityProperties[i].GetValue(entity, null);

                }
                dt.Rows.Add(entityValues);
            }
            return dt;
        }
    }
   

三..将Datatable类型数据转存到excel

//datable2excel  
        public static void ExportExcel(DataTable dt)
        {
            if (dt == null || dt.Rows.Count == 0) return;
            Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();

            if (xlApp == null)
            {
                return;
            }
            System.Globalization.CultureInfo CurrentCI = System.Threading.Thread.CurrentThread.CurrentCulture;
            System.Threading.Thread.CurrentThread.CurrentCulture = new System.Globalization.CultureInfo("en-US");
            Microsoft.Office.Interop.Excel.Workbooks workbooks = xlApp.Workbooks;
            Microsoft.Office.Interop.Excel.Workbook workbook = workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
            Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1];
            Microsoft.Office.Interop.Excel.Range range;
            long totalCount = dt.Rows.Count;
            long rowRead = 0;
            float percent = 0;
            for (int i = 0; i < dt.Columns.Count; i++)
            {
                worksheet.Cells[1, i + 1] = dt.Columns[i].ColumnName;
                range = (Microsoft.Office.Interop.Excel.Range)worksheet.Cells[1, i + 1];
                range.Interior.ColorIndex = 15;
                range.Font.Bold = true;
            }
            for (int r = 0; r < dt.Rows.Count; r++)
            {
                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    worksheet.Cells[r + 2, i + 1] = dt.Rows[r][i].ToString();
                }
                rowRead++;
                percent = ((float)(100 * rowRead)) / totalCount;
            }
            xlApp.Visible = true;
        }

四..简单使用

static void Main(string[] args)
        {
            //此设备为设备组中的chatdeevice_01, 
            string response = GetPage("http://api.heclouds.com/devices/25900768/datastreams");
            Root MyResult = JsonConvert.DeserializeObject(response, typeof(Root)) as Root;
            Console.WriteLine(response);
            System.Data.DataTable dt = new System.Data.DataTable();
            dt = ListToDatatable.ListToDataTable(MyResult.data);
            Console.WriteLine(MyResult.data);
            ExportExcel(dt);
            Console.Read();
        }