(转)使用NPOI导入导出标准Excel

原文链接:http://www.cnblogs.com/lwme/archive/2011/11/18/npoi_excel_import_export.html

 

 

尝试过很多Excel导入导出方法,都不太理想,无意中逛到oschina时,发现了NPOI,无需Office COM组件且不依赖Office,顿时惊为天人,怀着无比激动的心情写下此文。

曾使用过的方法

  1. 直接导出html,修改后缀名为.xls,这个方法有点像骗人的把戏,而且不能再导入
  2. 使用Jet OLEDB引擎来进行导入导出,完全使用sql语句来进行操作,缺点能控制的东西非常有限,比如格式就难以控制
  3. 使用Office COM组件进行导入导出,对环境依赖性太强(如“检索 COM 类工厂…”错误);且需要通过打开Excel.exe进程进行操作;虽然可以通过关闭工作表以及Marshal.ReleaseComObject方法来释放资源,但依然避免不了性能差。

关于NPOI

NPOIPOI项目的.NET版本,是由@Tony Qu(http://tonyqus.cnblogs.com/)等大侠基于POI开发的,可以从http://npoi.codeplex.com/下载到它的最新版本。它不使用Office COM组件(Microsoft.Office.Interop.XXX.dll),不需要安装Microsoft Office,支持对Office 97-2003的文件格式,功能比较强大。更详细的说明请看作者的博客或官方网站。

它的以下一些特性让我相当喜欢:

  1. 支持对标准的Excel读写
  2. 支持对流(Stream)的读写 (而Jet OLEDB和Office COM都只能针对文件)
  3. 支持大部分Office COM组件的常用功能
  4. 性能优异 (相对于前面的方法)
  5. 使用简单,易上手

使用NPOI

本文使用的是它当前的最新版本1.2.4,此版本的程序集缩减至2个:NPOI.dllIonic.Zip.dll,直接引用到项目中即可。

对于我们开发者使用的对象主要位于NPOI.HSSF.UserModel空间下,主要有HSSFWorkbookHSSFSheetHSSFRowHSSFCell,对应的接口为位于NPOI.SS.UserModel空间下的IWorkbookISheetIRowICell,分别对应Excel文件、工作表、行、列。

简单演示一下创建一个Workbook对象,添加一个工作表,在工作表中添加一行一列:

01using NPOI.HSSF.UserModel;
02using NPOI.SS.UserModel;
03
04public class NPOIWrite
05{
06    void CreateSheet()
07    {
08        IWorkbook workbook = new HSSFWorkbook();//创建Workbook对象
09        ISheet sheet = workbook.CreateSheet("Sheet1");//创建工作表
10        IRow row = sheet.CreateRow(0);//在工作表中添加一行
11        ICell cell = row.CreateCell(0);//在行中添加一列
12        cell.SetCellValue("test");//设置列的内容
13    }
14}

相应的读取代码:

01using System.IO;
02using NPOI.HSSF.UserModel;
03using NPOI.SS.UserModel;
04
05public class NPOIRead
06{
07    void GetSheet(Stream stream)
08    {
09        IWorkbook workbook = new HSSFWorkbook(stream);//从流内容创建Workbook对象
10        ISheet sheet = workbook.GetSheetAt(0);//获取第一个工作表
11        IRow row = sheet.GetRow(0);//获取工作表第一行
12        ICell cell = row.GetCell(0);//获取行的第一列
13        string value = cell.ToString();//获取列的值
14    }
15}

使用NPOI导出

从DataTable读取内容来创建Workbook对象:

01public static MemoryStream RenderToExcel(DataTable table)
02{
03    MemoryStream ms = new MemoryStream();
04
05    using (table)
06    {
07        using (IWorkbook workbook = new HSSFWorkbook())
08        {
09            using (ISheet sheet = workbook.CreateSheet())
10            {
11                IRow headerRow = sheet.CreateRow(0);
12
13                // handling header.
14                foreach (DataColumn column in table.Columns)
15                    headerRow.CreateCell(column.Ordinal).SetCellValue(column.Caption);//If Caption not set, returns the ColumnName value
16
17                // handling value.
18                int rowIndex = 1;
19
20                foreach (DataRow row in table.Rows)
21                {
22                    IRow dataRow = sheet.CreateRow(rowIndex);
23
24                    foreach (DataColumn column in table.Columns)
25                    {
26                        dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
27                    }
28
29                    rowIndex++;
30                }
31
32                workbook.Write(ms);
33                ms.Flush();
34                ms.Position = 0;
35            }
36        }
37    }
38    return ms;
39}

如果看不惯DataTable,那么DataReader也行:

01public static MemoryStream RenderToExcel(IDataReader reader)
02{
03    MemoryStream ms = new MemoryStream();
04
05    using (reader)
06    {
07        using (IWorkbook workbook = new HSSFWorkbook())
08        {
09            using (ISheet sheet = workbook.CreateSheet())
10            {
11                IRow headerRow = sheet.CreateRow(0);
12                int cellCount = reader.FieldCount;
13
14                // handling header.
15                for (int i = 0; i < cellCount; i++)
16                {
17                    headerRow.CreateCell(i).SetCellValue(reader.GetName(i));
18                }
19
20                // handling value.
21                int rowIndex = 1;
22                while (reader.Read())
23                {
24                    IRow dataRow = sheet.CreateRow(rowIndex);
25
26                    for (int i = 0; i < cellCount; i++)
27                    {
28                        dataRow.CreateCell(i).SetCellValue(reader[i].ToString());
29                    }
30
31                    rowIndex++;
32                }
33
34                workbook.Write(ms);
35                ms.Flush();
36                ms.Position = 0;
37            }
38        }
39    }
40    return ms;
41}

以上代码把创建的Workbook对象保存到流中,可以通过以下方法输出到浏览器,或是保存到硬盘中:

01static void SaveToFile(MemoryStream ms, string fileName)
02{
03    using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))
04    {
05        byte[] data = ms.ToArray();
06
07        fs.Write(data, 0, data.Length);
08        fs.Flush();
09
10        data = null;
11    }
12}
13
14static void RenderToBrowser(MemoryStream ms, HttpContext context, string fileName)
15{
16    if (context.Request.Browser.Browser == "IE")
17        fileName = HttpUtility.UrlEncode(fileName);
18    context.Response.AddHeader("Content-Disposition", "attachment;fileName=" + fileName);
19    context.Response.BinaryWrite(ms.ToArray());
20}

使用NPOI导入

需要注意的是,sheet.LastRowNum = sheet.PhysicalNumberOfRows - 1,这里可能存在BUG:当没有数据或只有一行数据时sheet.LastRowNum为0,PhysicalNumberOfRows 表现正常

这里读取流中的Excel来创建Workbook对象,并转换成DataTable:

01static DataTable RenderFromExcel(Stream excelFileStream)
02{
03    using (excelFileStream)
04    {
05        using (IWorkbook workbook = new HSSFWorkbook(excelFileStream))
06        {
07            using (ISheet sheet = workbook.GetSheetAt(0))//取第一个表
08            {
09                DataTable table = new DataTable();
10
11                IRow headerRow = sheet.GetRow(0);//第一行为标题行
12                int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells
13                int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1
14
15                //handling header.
16                for (int i = headerRow.FirstCellNum; i < cellCount; i++)
17                {
18                    DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);
19                    table.Columns.Add(column);
20                }
21
22                for (int i = (sheet.FirstRowNum + 1); i <= rowCount; i++)
23                {
24                    IRow row = sheet.GetRow(i);
25                    DataRow dataRow = table.NewRow();
26
27                    if (row != null)
28                    {
29                        for (int j = row.FirstCellNum; j < cellCount; j++)
30                        {
31                            if (row.GetCell(j) != null)
32                                dataRow[j] = GetCellValue(row.GetCell(j));
33                        }
34                    }
35
36                    table.Rows.Add(dataRow);
37                }
38                return table;
39
40            }
41        }
42    }
43}

或者是直接生成SQL语句来插入到数据库:

01public static int RenderToDb(Stream excelFileStream, string insertSql, DBAction dbAction)
02{
03    int rowAffected = 0;
04    using (excelFileStream)
05    {
06        using (IWorkbook workbook = new HSSFWorkbook(excelFileStream))
07        {
08            using (ISheet sheet = workbook.GetSheetAt(0))//取第一个工作表
09            {
10                StringBuilder builder = new StringBuilder();
11
12                IRow headerRow = sheet.GetRow(0);//第一行为标题行
13                int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells
14                int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1
15
16                for (int i = (sheet.FirstRowNum + 1); i <= rowCount; i++)
17                {
18                    IRow row = sheet.GetRow(i);
19                    if (row != null)
20                    {
21                        builder.Append(insertSql);
22                        builder.Append(" values (");
23                        for (int j = row.FirstCellNum; j < cellCount; j++)
24                        {
25                            builder.AppendFormat("'{0}',", GetCellValue(row.GetCell(j)).Replace("'", "''"));
26                        }
27                        builder.Length = builder.Length - 1;
28                        builder.Append(");");
29                    }
30
31                    if ((i % 50 == 0 || i == rowCount) && builder.Length > 0)
32                    {
33                        //每50条记录一次批量插入到数据库
34                        rowAffected += dbAction(builder.ToString());
35                        builder.Length = 0;
36                    }
37                }
38            }
39        }
40    }
41    return rowAffected;
42}

这里的Excel可能没有数据,所以可以加一个方法来检测:

01public static bool HasData(Stream excelFileStream)
02{
03    using (excelFileStream)
04    {
05        using (IWorkbook workbook = new HSSFWorkbook(excelFileStream))
06        {
07            if (workbook.NumberOfSheets > 0)
08            {
09                using (ISheet sheet = workbook.GetSheetAt(0))
10                {
11                    return sheet.PhysicalNumberOfRows > 0;
12                }
13            }
14        }
15    }
16    return false;
17}

结尾

好吧,不说啥了,放代码:点击下载

作者:囧月
出处:http://lwme.cnblogs.com/
本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接,否则保留追究法律责任的权利

posted on 2011-11-19 10:07  黑子范  阅读(584)  评论(1编辑  收藏  举报

导航