.NET基础架构方法—DataTableToExcel通用方法

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.NET架构基础方法—DataTableToExcel通用方法（NPOI）

今天封装DataTaleToExcel通用方法，也是大家开发中特别常用的。首先去下载NPOI，链接http://npoi.codeplex.com/ ，使用包中的net4.0版本的dll，全部引用。官网中已经给了足够的示例，我只拿来异步分，给类命名为ExcelTools.cs 。下面上代码

 using System;
 using System.Collections.Generic;
 using System.Data;
 using System.IO;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using NPOI.HPSF;
 using NPOI.HSSF.UserModel;

 namespace CommonUtilities
 {
     public static class ExcelTools
     {
         public static HSSFWorkbook workbook;

         public static void InitializeWorkbook()
         {
             ////create a entry of DocumentSummaryInformation
             if (workbook == null)
                 workbook = new HSSFWorkbook();
         }
         #region
         /// <summary>
         /// 将DataTable转成Stream输出.
         /// </summary>
         /// <param name="SourceTable">The source table.</param>
         /// <returns></returns>
         public static Stream RenderDataTableToExcel(DataTable SourceTable)
         {
             workbook = new HSSFWorkbook();
             InitializeWorkbook();
             MemoryStream ms = new MemoryStream();
             HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet();
             HSSFRow headerRow = (HSSFRow)sheet.CreateRow();

             // handling header.
             foreach (DataColumn column in SourceTable.Columns)
                 headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);

             // handling value.
             int rowIndex = ;

             foreach (DataRow row in SourceTable.Rows)
             {
                 HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);

                 foreach (DataColumn column in SourceTable.Columns)
                 {
                     dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
                 }

                 rowIndex++;
             }

             workbook.Write(ms);
             ms.Flush();
             ms.Position = ;

             sheet = null;
             headerRow = null;
             workbook = null;

             return ms;
         }

         public static void WriteSteamToFile(MemoryStream ms, string FileName)
         {
             FileStream fs = new FileStream(FileName, FileMode.Create, FileAccess.Write);
             byte[] data = ms.ToArray();

             fs.Write(data, , data.Length);
             fs.Flush();
             fs.Close();

             data = null;
             ms = null;
             fs = null;
         }
         public static void WriteSteamToFile(byte[] data, string FileName)
         {
             FileStream fs = new FileStream(FileName, FileMode.Create, FileAccess.Write);
             fs.Write(data, , data.Length);
             fs.Flush();
             fs.Close();
             data = null;
             fs = null;
         }
         public static Stream WorkBookToStream(HSSFWorkbook InputWorkBook)
         {
             MemoryStream ms = new MemoryStream();
             InputWorkBook.Write(ms);
             ms.Flush();
             ms.Position = ;
             return ms;
         }
         public static HSSFWorkbook StreamToWorkBook(Stream InputStream)
         {
             HSSFWorkbook WorkBook = new HSSFWorkbook(InputStream);
             return WorkBook;
         }
         public static HSSFWorkbook MemoryStreamToWorkBook(MemoryStream InputStream)
         {
             HSSFWorkbook WorkBook = new HSSFWorkbook(InputStream as Stream);
             return WorkBook;
         }
         public static MemoryStream WorkBookToMemoryStream(HSSFWorkbook InputStream)
         {
             //Write the stream data of workbook to the root directory
             MemoryStream file = new MemoryStream();
             InputStream.Write(file);
             return file;
         }
         public static Stream FileToStream(string FileName)
         {
             FileInfo fi = new FileInfo(FileName);
             if (fi.Exists == true)
             {
                 FileStream fs = new FileStream(FileName, FileMode.Open, FileAccess.Read);
                 return fs;
             }
             else return null;
         }
         public static Stream MemoryStreamToStream(MemoryStream ms)
         {
             return ms as Stream;
         }
         #endregion
         #region

         /// <summary>
         /// 将DataTable转成Workbook(自定资料形态)输出.
         /// </summary>
         /// <param name="SourceTable">The source table.</param>
         /// <returns></returns>
         public static HSSFWorkbook RenderDataTableToWorkBook(DataTable SourceTable)
         {
             workbook = new HSSFWorkbook();
             InitializeWorkbook();
             MemoryStream ms = new MemoryStream();
             HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet();
             HSSFRow headerRow = (HSSFRow)sheet.CreateRow();

             // handling header.
             foreach (DataColumn column in SourceTable.Columns)
                 headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);

             // handling value.
             int rowIndex = ;

             foreach (DataRow row in SourceTable.Rows)
             {
                 HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);

                 foreach (DataColumn column in SourceTable.Columns)
                 {
                     dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
                 }

                 rowIndex++;
             }
             return workbook;
         }

         /// <summary>
         /// 将DataTable资料输出成Excel.
         /// </summary>
         /// <param name="SourceTable">The source table.</param>
         /// <param name="FileName">Name of the file.</param>
         public static void RenderDataTableToExcel(DataTable SourceTable, string FileName)
         {
             MemoryStream ms = RenderDataTableToExcel(SourceTable) as MemoryStream;
             WriteSteamToFile(ms, FileName);
         }

         /// <summary>
         /// 從位元读取取资料到DataTable.
         /// </summary>
         /// <param name="ExcelFileStream">The excel file stream.</param>
         /// <param name="SheetName">Name of the sheet.</param>
         /// <param name="HeaderRowIndex">Index of the header row.</param>
         /// <param name="HaveHeader">if set to <c>true</c> [have header].</param>
         /// <returns></returns>
         public static DataTable RenderDataTableFromExcel(Stream ExcelFileStream, string SheetName, int HeaderRowIndex, bool HaveHeader)
         {
             workbook = new HSSFWorkbook(ExcelFileStream);
             InitializeWorkbook();
             HSSFSheet sheet = (HSSFSheet)workbook.GetSheet(SheetName);

             DataTable table = new DataTable();

             HSSFRow headerRow = (HSSFRow)sheet.GetRow(HeaderRowIndex);
             int cellCount = headerRow.LastCellNum;

             for (int i = headerRow.FirstCellNum; i < cellCount; i++)
             {
                 string ColumnName = (HaveHeader == true) ? headerRow.GetCell(i).StringCellValue : "f" + i.ToString();
                 DataColumn column = new DataColumn(ColumnName);
                 table.Columns.Add(column);
             }

             int rowCount = sheet.LastRowNum;
             int RowStart = (HaveHeader == true) ? sheet.FirstRowNum +  : sheet.FirstRowNum;
             for (int i = RowStart; i <= sheet.LastRowNum; i++)
             {
                 HSSFRow row = (HSSFRow)sheet.GetRow(i);
                 DataRow dataRow = table.NewRow();

                 for (int j = row.FirstCellNum; j < cellCount; j++)
                     dataRow[j] = row.GetCell(j).ToString();
             }

             ExcelFileStream.Close();
             workbook = null;
             sheet = null;
             return table;
         }

         /// <summary>
         /// 從位元流读取资料到DataTable.
         /// </summary>
         /// <param name="ExcelFileStream">The excel file stream.</param>
         /// <param name="SheetIndex">Index of the sheet.</param>
         /// <param name="HeaderRowIndex">Index of the header row.</param>
         /// <param name="HaveHeader">if set to <c>true</c> [have header].</param>
         /// <returns></returns>
         public static DataTable RenderDataTableFromExcel(Stream ExcelFileStream, int SheetIndex, int HeaderRowIndex, bool HaveHeader)
         {
             workbook = new HSSFWorkbook(ExcelFileStream);
             InitializeWorkbook();
             HSSFSheet sheet = (HSSFSheet)workbook.GetSheetAt(SheetIndex);

             DataTable table = new DataTable();

             HSSFRow headerRow = (HSSFRow)sheet.GetRow(HeaderRowIndex);
             int cellCount = headerRow.LastCellNum;

             for (int i = headerRow.FirstCellNum; i < cellCount; i++)
             {
                 string ColumnName = (HaveHeader == true) ? headerRow.GetCell(i).StringCellValue : "f" + i.ToString();
                 DataColumn column = new DataColumn(ColumnName);
                 table.Columns.Add(column);
             }

             int rowCount = sheet.LastRowNum;
             int RowStart = (HaveHeader == true) ? sheet.FirstRowNum +  : sheet.FirstRowNum;
             for (int i = RowStart; i <= sheet.LastRowNum; i++)
             {
                 HSSFRow row = (HSSFRow)sheet.GetRow(i);
                 DataRow dataRow = table.NewRow();

                 for (int j = row.FirstCellNum; j < cellCount; j++)
                 {
                     if (row.GetCell(j) != null)
                         dataRow[j] = row.GetCell(j).ToString();
                 }

                 table.Rows.Add(dataRow);
             }

             ExcelFileStream.Close();
             workbook = null;
             sheet = null;
             return table;
         }
         #endregion
     }
 }

有了这段代码之后，我们希望进一步封装，新建一个DataTableRender.cs类，在这个类中，我只封装出一个方法，其他方法都可以通过调用ExcelTools.cs类中的方法来进一步封装。代码如下：

 public static class DataTableRender
    {
        /// <summary>
            ///
            /// </summary>
            /// <param name="dt">DataTable</param>
            /// <param name="path">当前 FileStream 对象将封装的文件的相对路径或绝对路径。</param>
            public static void DateTableToExcel(DataTable dt, string path)
        {
            MemoryStream stream = (MemoryStream)ExcelTools.RenderDataTableToExcel(dt);
            byte[] buffer = stream.ToArray();
            using (FileStream fs = new FileStream(path, FileMode.Create, FileAccess.Write))
            {
                fs.Write(buffer, , buffer.Length);
                fs.Flush();
            }
        }
    }

就这样简单的方便了你今后的开发。