用c读取excel的三种方法

1、C#读取Excel的三种方法及比较（1）OleDB方式优点：将Excel直接当做数据源处理，通过SQL直接读取内容，读取速度较快。缺点：读取数据方式不够灵活，无法直接读取某一个单元格，只有将整个Sheet页读取出来后（结果为Datatable）再在Datatable中根据行列数来获取指定的值。           当Excel数据量很大时。会非常占用内存，当内存不够时会抛出内存溢出的异常。读取代码如下： 1: public DataTable GetExcelTableByOleDB(strin

2、g strExcelPath, string tableName) 2: 3: try 4: 5: DataTable dtExcel = new DataTable(); 6: /数据表 7: DataSet ds = new DataSet(); 8: /获取文件扩展名 9: string strExtension = System.IO.Path.GetExtension(strExcelPath); 10: string strFileName = System.IO.Path.GetFileName(strExcelPath); 11: /Excel的连接 12: OleDbConn

3、ection objConn = null; 13: switch (strExtension) 14: 15: case ".xls": 16: objConn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + strExcelPath + "" + "Extended Properties="Excel 8.0;HDR=NO;IMEX=1;""); 17: break; 18: case "

4、;.xlsx": 19: objConn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strExcelPath + "" + "Extended Properties="Excel 12.0;HDR=NO;IMEX=1;""); 20: break; 21: default: 22: objConn = null; 23: break; 24: 25: if (objConn = null) 26: 27

5、: return null; 28: 29: objConn.Open(); 30: /获取Excel中所有Sheet表的信息 31: /System.Data.DataTable schemaTable = objConn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null); 32: /获取Excel的第一个Sheet表名 33: /string tableName = schemaTable.Rows02.ToString().Trim(); 34: string strSql = "select

6、 * from " + tableName + "" 35: /获取Excel指定Sheet表中的信息 36: OleDbCommand objCmd = new OleDbCommand(strSql, objConn); 37: OleDbDataAdapter myData = new OleDbDataAdapter(strSql, objConn); 38: myData.Fill(ds, tableName);/填充数据 39: objConn.Close(); 40: /dtExcel即为excel文件中指定表中存储的信息 41: dtExcel =

7、 ds.TablestableName; 42: return dtExcel; 43: 44: catch 45: 46: return null; 47: 48: 下面说明一下连接字符串        HDR=Yes，这代表第一行是标题，不做为数据使用（但是我在实际使用中，如果第一行存在复杂数值，那么读取得到的Datatable列标题会自动设置为F1、F2等方式命名，与实际应用不符，所以当时是通过HDR=No方式将所有内容读取到Datatable中，然后手动将第一行设置成标题的）；IMEX ( IMport EXport

8、 mode )设置 IMEX 有三种模式： 0 is Export mode 1 is Import mode 2 is Linked mode (full update capabilities) 我这里特别要说明的就是 IMEX 参数了，因为不同的模式代表著不同的读写行为： 当 IMEX=0 时为“汇出模式”，这个模式开启的 Excel 档案只能用来做“写入”用途。 当 IMEX=1 时为“汇入模式”，这个模式开启的 Excel 档案只能用来做“读取”用途。 当 IMEX=2 时为“链接模式”，这个模式开启的

9、Excel 档案可同时支援“读取”与“写入”用途。-另外，读取Excel2007版本的文件时，版本应该从8.0改为12.0，同时驱动不能再用Jet，而应该用ACE。负责会造成“找不到可安装的 ISAM”的错误。-在网上还发现采用这种方式存在取出的Sheet表的个数多于实际Excel表中的Sheet表个数的情况，其原因有二：1. 取出的名称中，包括了XL命名管理器中的名称（参见XL2007的公式-命名管理器， 快捷键Crtl+F3）；2. 取出的名称中，包括了FilterDatabase后缀的， 这是XL用来记录Filter范围的。对于第一点比较简单， 删除已有命名管理器中的内容即可；第二点处理

10、起来比较麻烦， Filter删除后这些名称依然保留着，简单的做法是新增Sheet然后将原Sheet Copy进去。但实际情况并不能为每个Excel做以上检查。下面给出了过滤的方案。（此问题我们有验证过，大家自己验证一下吧） 1: /objConn为读取Excel的链接，下面通过过滤来获取有效的Sheet页名称集合 2: System.Data.DataTable schemaTable = objConn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null); 3: List<string> lstS

11、heetNames = new List<string>(); 4: for (int i = 0; i < schemaTable.Rows.Count; i+) 5: 6: string strSheetName = (string)dtSheetName.Rowsi"TABLE_NAME" 7: if (strSheetName.Contains("$") && !strSheetName.Replace("'", "").EndsWith("$"

12、) 8: 9: /过滤无效SheetName完毕. 10: continue; 11: 12: if (lstSheetNames != null && !lstSheetNames.Contains(strSheetName) 13: lstSheetNames.Add(strSheetName); 14: 因为读取出来无效SheetName一般情况最后一个字符都不会是$。如果SheetName有一些特殊符号，读取出来的SheetName会自动加上单引号。比如在Excel中将SheetName编辑成MySheet(1)，此时读取出来的SheetName就为：'MySh

13、eet(1)$'，所以判断最后一个字符是不是$之前最好过滤一下单引号。-（2）Com组件的方式（通过添加 Microsoft.Office.Interop.Excel引用实现）优点：能够非常灵活的读取Excel中的数据，用户可以灵活的调用各种函数进行处理。缺点：基于单元格的处理，读取速度较慢，对于数据量较大的文件最好不要使用此种方式读取。           需要添加相应的DLL引用，必须存在此引用才可使用，如果是Web站点部署在IIS上时，还需要服务器机子已安装了Excel，有时候还需

14、要为配置IIS权限。读取代码如下： 1: private Stopwatch wath = new Stopwatch(); 2: / <summary> 3: / 使用COM读取Excel 4: / </summary> 5: / <param name="excelFilePath">路径</param> 6: / <returns>DataTabel</returns> 7: public System.Data.DataTable GetExcelData(string excelFilePat

15、h) 8: 9: Excel.Application app = new Excel.Application(); 10: Excel.Sheets sheets; 11: Excel.Workbook workbook = null; 12: object oMissiong = System.Reflection.Missing.Value; 13: System.Data.DataTable dt = new System.Data.DataTable(); 14: wath.Start(); 15: try 16: 17: if (app = null) 18: 19: return

16、null; 20: 21: workbook = app.Workbooks.Open(excelFilePath, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, 22: oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong); 23: /将数据读入到DataTable中Start 24: sheets = workbook.Worksheets; 25: Excel.Worksheet w

17、orksheet = (Excel.Worksheet)sheets.get_Item(1);/读取第一张表 26: if (worksheet = null) 27: return null; 28: string cellContent; 29: int iRowCount = worksheet.UsedRange.Rows.Count; 30: int iColCount = worksheet.UsedRange.Columns.Count; 31: Excel.Range range; 32: /负责列头Start 33: DataColumn dc; 34: int Column

18、ID = 1; 35: range = (Excel.Range)worksheet.Cells1, 1; 36: while (range.Text.ToString().Trim() != "") 37: 38: dc = new DataColumn(); 39: dc.DataType = System.Type.GetType("System.String"); 40: dc.ColumnName = range.Text.ToString().Trim(); 41: dt.Columns.Add(dc); 42: 43: range = (E

19、xcel.Range)worksheet.Cells1, +ColumnID; 44: 45: /End 46: for (int iRow = 2; iRow <= iRowCount; iRow+) 47: 48: DataRow dr = dt.NewRow(); 49: for (int iCol = 1; iCol <= iColCount; iCol+) 50: 51: range = (Excel.Range)worksheet.CellsiRow, iCol; 52: cellContent = (range.Value2 = null) ? ""

20、; : range.Text.ToString(); 53: driCol - 1 = cellContent; 54: 55: dt.Rows.Add(dr); 56: 57: wath.Stop(); 58: TimeSpan ts = wath.Elapsed; 59: /将数据读入到DataTable中End 60: return dt; 61: 62: catch 63: 64: return null; 65: 66: finally 67: 68: workbook.Close(false, oMissiong, oMissiong); 69: System.Runtime.In

21、teropServices.Marshal.ReleaseComObject(workbook); 70: workbook = null; 71: app.Workbooks.Close(); 72: app.Quit(); 73: System.Runtime.InteropServices.Marshal.ReleaseComObject(app); 74: app = null; 75: GC.Collect(); 76: GC.WaitForPendingFinalizers(); 77: 78: 79: / <summary> 80: / 使用COM，多线程读取Exce

22、l（1 主线程、4 副线程） 81: / </summary> 82: / <param name="excelFilePath">路径</param> 83: / <returns>DataTabel</returns> 84: public System.Data.DataTable ThreadReadExcel(string excelFilePath) 85: 86: Excel.Application app = new Excel.Application(); 87: Excel.Sheets she

23、ets = null; 88: Excel.Workbook workbook = null; 89: object oMissiong = System.Reflection.Missing.Value; 90: System.Data.DataTable dt = new System.Data.DataTable(); 91: wath.Start(); 92: try 93: 94: if (app = null) 95: 96: return null; 97: 98: workbook = app.Workbooks.Open(excelFilePath, oMissiong, o

24、Missiong, oMissiong, oMissiong, oMissiong, oMissiong, 99: oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong); 100: /将数据读入到DataTable中Start 101: sheets = workbook.Worksheets; 102: Excel.Worksheet worksheet = (Excel.Worksheet)sheets.get_Item(1);/读取第一张表 103: if (work

25、sheet = null) 104: return null; 105: string cellContent; 106: int iRowCount = worksheet.UsedRange.Rows.Count; 107: int iColCount = worksheet.UsedRange.Columns.Count; 108: Excel.Range range; 109: /负责列头Start 110: DataColumn dc; 111: int ColumnID = 1; 112: range = (Excel.Range)worksheet.Cells1, 1; 113:

26、 while (iColCount >= ColumnID) 114: 115: dc = new DataColumn(); 116: dc.DataType = System.Type.GetType("System.String"); 117: string strNewColumnName = range.Text.ToString().Trim(); 118: if (strNewColumnName.Length = 0) strNewColumnName = "_1" 119: /判断列名是否重复 120: for (int i =

27、1; i < ColumnID; i+) 121: 122: if (dt.Columnsi - 1.ColumnName = strNewColumnName) 123: strNewColumnName = strNewColumnName + "_1" 124: 125: dc.ColumnName = strNewColumnName; 126: dt.Columns.Add(dc); 127: range = (Excel.Range)worksheet.Cells1, +ColumnID; 128: 129: /End 130: /数据大于500条，使用多

28、进程进行读取数据 131: if (iRowCount - 1 > 500) 132: 133: /开始多线程读取数据 134: /新建线程 135: int b2 = (iRowCount - 1) / 10; 136: DataTable dt1 = new DataTable("dt1"); 137: dt1 = dt.Clone(); 138: SheetOptions sheet1thread = new SheetOptions(worksheet, iColCount, 2, b2 + 1, dt1); 139: Thread othread1 = ne

29、w Thread(new ThreadStart(sheet1thread.SheetToDataTable); 140: othread1.Start(); 141: /阻塞 1 毫秒，保证第一个读取 dt1 142: Thread.Sleep(1); 143: DataTable dt2 = new DataTable("dt2"); 144: dt2 = dt.Clone(); 145: SheetOptions sheet2thread = new SheetOptions(worksheet, iColCount, b2 + 2, b2 * 2 + 1, dt2)

30、; 146: Thread othread2 = new Thread(new ThreadStart(sheet2thread.SheetToDataTable); 147: othread2.Start(); 148: DataTable dt3 = new DataTable("dt3"); 149: dt3 = dt.Clone(); 150: SheetOptions sheet3thread = new SheetOptions(worksheet, iColCount, b2 * 2 + 2, b2 * 3 + 1, dt3); 151: Thread oth

31、read3 = new Thread(new ThreadStart(sheet3thread.SheetToDataTable); 152: othread3.Start(); 153: DataTable dt4 = new DataTable("dt4"); 154: dt4 = dt.Clone(); 155: SheetOptions sheet4thread = new SheetOptions(worksheet, iColCount, b2 * 3 + 2, b2 * 4 + 1, dt4); 156: Thread othread4 = new Threa

32、d(new ThreadStart(sheet4thread.SheetToDataTable); 157: othread4.Start(); 158: /主线程读取剩余数据 159: for (int iRow = b2 * 4 + 2; iRow <= iRowCount; iRow+) 160: 161: DataRow dr = dt.NewRow(); 162: for (int iCol = 1; iCol <= iColCount; iCol+) 163: 164: range = (Excel.Range)worksheet.CellsiRow, iCol; 16

33、5: cellContent = (range.Value2 = null) ? "" : range.Text.ToString(); 166: driCol - 1 = cellContent; 167: 168: dt.Rows.Add(dr); 169: 170: othread1.Join(); 171: othread2.Join(); 172: othread3.Join(); 173: othread4.Join(); 174: /将多个线程读取出来的数据追加至 dt1 后面 175: foreach (DataRow dr in dt.Rows) 176:

34、 dt1.Rows.Add(dr.ItemArray); 177: dt.Clear(); 178: dt.Dispose(); 179: foreach (DataRow dr in dt2.Rows) 180: dt1.Rows.Add(dr.ItemArray); 181: dt2.Clear(); 182: dt2.Dispose(); 183: foreach (DataRow dr in dt3.Rows) 184: dt1.Rows.Add(dr.ItemArray); 185: dt3.Clear(); 186: dt3.Dispose(); 187: foreach (Dat

35、aRow dr in dt4.Rows) 188: dt1.Rows.Add(dr.ItemArray); 189: dt4.Clear(); 190: dt4.Dispose(); 191: return dt1; 192: 193: else 194: 195: for (int iRow = 2; iRow <= iRowCount; iRow+) 196: 197: DataRow dr = dt.NewRow(); 198: for (int iCol = 1; iCol <= iColCount; iCol+) 199: 200: range = (Excel.Rang

36、e)worksheet.CellsiRow, iCol; 201: cellContent = (range.Value2 = null) ? "" : range.Text.ToString(); 202: driCol - 1 = cellContent; 203: 204: dt.Rows.Add(dr); 205: 206: 207: wath.Stop(); 208: TimeSpan ts = wath.Elapsed; 209: /将数据读入到DataTable中End 210: return dt; 211: 212: catch 213: 214: ret

37、urn null; 215: 216: finally 217: 218: workbook.Close(false, oMissiong, oMissiong); 219: System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook); 220: System.Runtime.InteropServices.Marshal.ReleaseComObject(sheets); 221: workbook = null; 222: app.Workbooks.Close(); 223: app.Quit(); 224: Sys

38、tem.Runtime.InteropServices.Marshal.ReleaseComObject(app); 225: app = null; 226: GC.Collect(); 227: GC.WaitForPendingFinalizers(); 228: 229: -（3）NPOI方式读取Excel（此方法未经过测试）NPOI 是 POI 项目的 .NET 版本。POI是一个开源的Java读写Excel、WORD等微软OLE2组件文档的项目。使用 NPOI 你就可以在没有安装 Office 或者相应环境的机器上对 WORD/EXCEL 文档进行读写。优点：读

39、取Excel速度较快，读取方式操作灵活性缺点：需要下载相应的插件并添加到系统引用当中。 1: / <summary> 2: / 将excel中的数据导入到DataTable中 3: / </summary> 4: / <param name="sheetName">excel工作薄sheet的名称</param> 5: / <param name="isFirstRowColumn">第一行是否是DataTable的列名</param> 6: / <returns>返回的DataTable</returns> 7: public DataTable ExcelToDataTable(string sheetName, bool isFirstRowColumn) 8: 9: ISheet sheet = null; 10: DataTable data = new DataTable(); 11: int startRow = 0; 12: try 13: 14: fs = new FileStream(fileName, FileMode.Open,