using System.Collections.Generic;

using System.Data;

using System.IO;

using System.Linq;

using System.Web;

namespace MVCStudy.Helper

{

    public class ExcelHandle

    {

        /// <summary>

        /// 将DataTable数据导出到Excel文件中(xlsx)

        /// </summary>

        /// <param name="dt">数据源</param>

        /// <param name="excelName">文件名称</param>

        public static void TableToExcelForXLSX(DataTable dt, string excelName)

        {

            XSSFWorkbook xssfworkbook = new XSSFWorkbook();

            ISheet sheet = xssfworkbook.CreateSheet("Test");

            //表头

            IRow row = sheet.CreateRow();

            for (int i = ; i < dt.Columns.Count; i++)

            {

                ICell cell = row.CreateCell(i);

                cell.SetCellValue(dt.Columns[i].ColumnName);

            }

            //数据

            for (int i = ; i < dt.Rows.Count; i++)

            {

                IRow row1 = sheet.CreateRow(i + );

                for (int j = ; j < dt.Columns.Count; j++)

                {

                    ICell cell = row1.CreateCell(j);

                    cell.SetCellValue(dt.Rows[i][j].ToString());

                }

            }

            HttpContext curContext = HttpContext.Current;

            curContext.Response.Clear();

            curContext.Response.ContentType = "application/x-excel";

            string filename = HttpUtility.UrlEncode(excelName + DateTime.Now.ToString("yyyyMMddHHmm") + ".xlsx");

            curContext.Response.AddHeader("Content-Disposition", "attachment;filename=" + filename);

            xssfworkbook.Write(curContext.Response.OutputStream);

            curContext.Response.End();

        }

        /// <summary>

        /// 读取excel（版本不低于2007）至DataTable

        /// </summary>

        /// <param name="file"></param>

        /// <returns></returns>

        public static DataTable ExcelToTableForXLSX(string file)

        {

            DataTable dt = new DataTable();

            using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))

            {

                XSSFWorkbook xssfworkbook = new XSSFWorkbook(fs);

                ISheet sheet = xssfworkbook.GetSheetAt();

                //表头

                IRow header = sheet.GetRow(sheet.FirstRowNum);

                List<int> columns = new List<int>();

                for (int i = ; i < header.LastCellNum; i++)

                {

                    object obj = GetValueTypeForXLSX(header.GetCell(i) as XSSFCell);

                    if (obj == null || obj.ToString() == string.Empty)

                    {

                        dt.Columns.Add(new DataColumn("Columns" + i.ToString()));

                    }

                    else

                        dt.Columns.Add(new DataColumn(obj.ToString()));

                    columns.Add(i);

                }

                //数据

                for (int i = sheet.FirstRowNum + ; i <= sheet.LastRowNum; i++)

                {

                    DataRow dr = dt.NewRow();

                    bool hasValue = false;

                    foreach (int j in columns)

                    {

                        dr[j] = GetValueTypeForXLSX(sheet.GetRow(i).GetCell(j) as XSSFCell);

                        if (dr[j] != null && dr[j].ToString() != string.Empty)

                        {

                            hasValue = true;

                        }

                    }

                    if (hasValue)

                    {

                        dt.Rows.Add(dr);

                    }

                }

            }

            return dt;

        }

        /// <summary>

        /// 获取单元格类型(xlsx)

        /// </summary>

        /// <param name="cell"></param>

        /// <returns></returns>

        private static object GetValueTypeForXLSX(XSSFCell cell)

        {

            if (cell == null)

                return null;

            switch (cell.CellType)

            {

                case CellType.Blank: //BLANK:

                    return null;

                case CellType.Boolean: //BOOLEAN:

                    return cell.BooleanCellValue;

                case CellType.Numeric: //NUMERIC:

                    return cell.NumericCellValue;

                case CellType.String: //STRING:

                    return cell.StringCellValue;

                case CellType.Error: //ERROR:

                    return cell.ErrorCellValue;

                case CellType.Formula: //FORMULA:

                default:

                    return "=" + cell.CellFormula;

            }

        }

        /// <summary>

        /// 将List导出到Excel

        /// </summary>

        /// <param name="enList">List数据</param>

        /// <param name="fileName">Excel文件名</param>

        /// <param name="sheetName">Excel工作表名</param>

        /// <param name="cell0Value">首行提示信息</param>

        public void IListToExcel( IList enList, string fileName, string sheetName,string cell0Value)

        {

            IWorkbook workbook = new XSSFWorkbook();

            ISheet sheet = workbook.CreateSheet(sheetName);

            sheet.CreateRow().CreateCell().SetCellValue(cell0Value);

            List<string> Ihead = new List<string>();

            Type types = enList[].GetType();

            foreach(var item in types.GetProperties())

            {

                Ihead.Add(item.Name);

            }

            IRow row1 = sheet.CreateRow();

            for (int i = ; i < Ihead.Count; i++)

            {

                row1.CreateCell(i).SetCellValue(Ihead[i]);

            }

            int rowIndex = ;

            foreach (var item in enList)

            {

                IRow rowTmp = sheet.CreateRow(rowIndex);

                for (int i = ; i < Ihead.Count; i++)

                {

                    System.Reflection.PropertyInfo properotyInfo = item.GetType().GetProperty(Ihead[i]); // 属性的信息

                    object properotyValue = properotyInfo.GetValue(item, null);// 属性的值

                    string cellValue = properotyValue.ToString()??null;// 单元格的值

                    rowTmp.CreateCell(i).SetCellValue(cellValue);

                }

                rowIndex++;

            }

            using (FileStream file = new FileStream(fileName, FileMode.Create))

            {

                workbook.Write(file);

                file.Close();

            }

        }

    }

}