用c#读取Excel的三种方法.doc
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_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(string 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: OleDbConnection 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 .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: 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 * 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 = 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 mode )设置IMEX 有三种模式:0 is Export mode1 is Import mode2 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 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 lstSheetNames = new List(); 4: for (int i = 0; i schemaTable.Rows.Count; i+) 5: 6: string strSheetName = (string)dtSheetName.RowsiTABLE_NAME; 7: if (strSheetName.Contains($) & !strSheetName.Replace(, ).EndsWith($) 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$。如果SheetName有一些特殊符号,读取出来的SheetName会自动加上单引号。比如在Excel中将SheetName编辑成MySheet(1),此时读取出来的SheetName就为:MySheet(1)$,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,有时候还需要为配置IIS权限。读取代码如下: 1: private Stopwatch wath = new Stopwatch(); 2: / 3: / 使用COM读取Excel 4: / 5: / 路径 6: / DataTabel 7: public System.Data.DataTable GetExcelData(string excelFilePath) 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 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 worksheet = (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 ColumnID = 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 = (Excel.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) ? : 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.InteropServices.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: / 80: / 使用COM,多线程读取Excel(1 主线程、4 副线程) 81: / 82: / 路径 83: / DataTabel 84: public System.Data.DataTable ThreadReadExcel(string excelFilePath) 85: 86: Excel.Application app = new Excel.Application(); 87: Excel.Sheets sheets = 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, oMissiong, 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 (worksheet = 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: 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 = 1; i 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 = new 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); 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 othread3 = 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 Thread(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; 165: 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: 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 (DataRow 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.Range)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: return 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: System.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: / 2: / 将excel中的数据导入到DataTable中 3: / 4: / excel工作薄sheet的名称 5: / 第一行是否是DataTable的列名 6: / 返回的DataTable 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, FileAccess.Read); 15: if (fileName.IndexOf(.xlsx) 0) / 2007版本 16: workbook = new XSSFWorkbook(fs); 17: else if (fileName.IndexOf(.xls) 0) / 2003版本 18: workbook = new HSSFWorkbook(fs); 19: if (sheetName != null) 20: 21: sheet = workbook.GetSheet(sheetName); 22: 23: else 24: 25: sheet = workbook.GetSheetAt(0); 26: 27: if (sheet != null) 28: 29: IRow firstRow = sheet.GetRow(0); 30: int cellCount = firstRow.LastCellNum; /一行最后一个cell的编号 即总的列数 31: if (isFirstRowColumn) 32: 33: for (int i = firstRow.FirstCellNum; i cellCount; +i) 34: 35: DataColumn column = new DataColumn(firstRow.GetCell(i).StringCellValue); 36: data.Columns.Add(column); 37: 38: startRow = sheet.FirstRowNum + 1; 39: 40: else 41: 42: startRow = sheet.FirstRowNum; 43: 44: /最后一列的标号 45: int rowCount = sheet.LastRowNum; 46: for (int i = startRow; i = rowCount; +i) 47: 48: IRow row = sheet.GetRow(i); 49: if (row = null) continue; /没有数据的行默认是null 50: 51: DataRow dataRow = data.NewRow(); 52: for (int j = row.FirstCellNum; j cellCount; +j) 53: 54: if (row.GetCell(j) != null) /同理,没有数据的单元格都默认是null 55: dataRowj = row.GetCell(j).ToString(); 56: 57: data.Rows.Add(dataRow); 58: 59: 60: return data; 61: 62: catch (Exception ex) 63: 64: Console.WriteLine(Exception: + ex.Message); 65: return null; 66: 67: 本人热爱大数据挖掘方面,也经常用C#、R、Python做数据挖掘,搜索微信公众号“数据挖掘工作室”或扫描下方二维码,精彩多多。THANKS !致力为企业和个人提供合同协议,策划案计划书,学习课件等等打造全网一站式需求欢迎您的下载,资料仅供参考-可编辑修改-- 配套讲稿:
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