方法一:OleDb: 用这种方法读取Excel速度还是非常的快的,但这种方式读取数据的时候不太灵活,不过可以在 DataTable 中对数据进行一些删减修改。
优点:读取方式简单、读取速度快
缺点:除了读取过程不太灵活之外,这种读取方式还有个弊端就是,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。
不过一般情况下还是非常不错的。
(代码比原文相较有所修改)
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DataTable GetDataFromExcelByConn( bool hasTitle = false ) { OpenFileDialog openFile = new OpenFileDialog(); openFile.Filter = "Excel(*.xlsx)|*.xlsx|Excel(*.xls)|*.xls" ; openFile.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop); openFile.Multiselect = false ; if (openFile.ShowDialog() == DialogResult.Cancel) return null ; var filePath = openFile.FileName; string fileType = System.IO.Path.GetExtension(filePath); if ( string .IsNullOrEmpty(fileType)) return null ; using (DataSet ds = new DataSet()) { string strCon = string .Format( "Provider=Microsoft.Jet.OLEDB.{0}.0;" + "Extended Properties=\"Excel {1}.0;HDR={2};IMEX=1;\";" + "data source={3};" , (fileType == ".xls" ? 4 : 12), (fileType == ".xls" ? 8 : 12), (hasTitle ? "Yes" : "NO" ), filePath); string strCom = " SELECT * FROM [Sheet1$]" ; using (OleDbConnection myConn = new OleDbConnection(strCon)) using (OleDbDataAdapter myCommand = new OleDbDataAdapter(strCom, myConn)) { myConn.Open(); myCommand.Fill(ds); } if (ds == null || ds.Tables.Count <= 0) return null ; return ds.Tables[0]; } } |
方法二:Com组件的方式读取Excel
这种方式需要先引用 Microsoft.Office.Interop.Excel 。首选说下这种方式的优缺点
优点:可以非常灵活的读取Excel中的数据
缺点: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。最重要的一点因为是基于单元格方式读取的,所以数据很慢(曾做过试验,直接读取千行、200多列的文件,直接读取耗时15分钟。即使采用多线程分段读取来提高CPU的利用率也需要8分钟。PS:CPU I3)
需要读取大文件的的童鞋们慎重。。。
(代码比原文相较有所修改)
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DataTable GetDataFromExcelByCom( bool hasTitle = false ) { OpenFileDialog openFile = new OpenFileDialog(); openFile.Filter = "Excel(*.xlsx)|*.xlsx|Excel(*.xls)|*.xls" ; openFile.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop); openFile.Multiselect = false ; if (openFile.ShowDialog() == DialogResult.Cancel) return null ; var excelFilePath = openFile.FileName; Excel.Application app = new Excel.Application(); Excel.Sheets sheets; object oMissiong = System.Reflection.Missing.Value; Excel.Workbook workbook = null ; DataTable dt = new DataTable(); try { if (app == null ) return null ; workbook = app.Workbooks.Open(excelFilePath, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong); sheets = workbook.Worksheets; //将数据读入到DataTable中 Excel.Worksheet worksheet = (Excel.Worksheet)sheets.get_Item(1); //读取第一张表 if (worksheet == null ) return null ; int iRowCount = worksheet.UsedRange.Rows.Count; int iColCount = worksheet.UsedRange.Columns.Count; //生成列头 for ( int i = 0; i < iColCount; i++) { var name = "column" + i; if (hasTitle) { var txt = ((Excel.Range)worksheet.Cells[1, i + 1]).Text.ToString(); if (! string .IsNullOrWhiteSpace(txt)) name = txt; } while (dt.Columns.Contains(name)) name = name + "_1" ; //重复行名称会报错。 dt.Columns.Add( new DataColumn(name, typeof ( string ))); } //生成行数据 Excel.Range range; int rowIdx = hasTitle ? 2 : 1; for ( int iRow = rowIdx; iRow <= iRowCount; iRow++) { DataRow dr = dt.NewRow(); for ( int iCol = 1; iCol <= iColCount; iCol++) { range = (Excel.Range)worksheet.Cells[iRow, iCol]; dr[iCol - 1] = (range.Value2 == null ) ? "" : range.Text.ToString(); } dt.Rows.Add(dr); } return dt; } catch { return null ; } finally { workbook.Close( false , oMissiong, oMissiong); System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook); workbook = null ; app.Workbooks.Close(); app.Quit(); System.Runtime.InteropServices.Marshal.ReleaseComObject(app); app = null ; } } |
原文的方法二还提供了多线程处理数据的代码,一并复制到此(此处出现了一个SheetOptions的类型,无法考证其来源,如果知晓,请留言,谢谢。):
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/// <summary> /// 使用COM,多线程读取Excel(1 主线程、4 副线程) /// </summary> /// <param name="excelFilePath">路径</param> /// <returns>DataTabel</returns> public System.Data.DataTable ThreadReadExcel( string excelFilePath) { Excel.Application app = new Excel.Application(); Excel.Sheets sheets = null ; Excel.Workbook workbook = null ; object oMissiong = System.Reflection.Missing.Value; System.Data.DataTable dt = new System.Data.DataTable(); try { if (app == null ) { return null ; } workbook = app.Workbooks.Open(excelFilePath, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong); //将数据读入到DataTable中——Start sheets = workbook.Worksheets; Excel.Worksheet worksheet = (Excel.Worksheet)sheets.get_Item(1); //读取第一张表 if (worksheet == null ) return null ; string cellContent; int iRowCount = worksheet.UsedRange.Rows.Count; int iColCount = worksheet.UsedRange.Columns.Count; Excel.Range range; //负责列头Start DataColumn dc; int ColumnID = 1; range = (Excel.Range)worksheet.Cells[1, 1]; //while (range.Text.ToString().Trim() != "") while (iColCount >= ColumnID) { dc = new DataColumn(); dc.DataType = System.Type.GetType( "System.String" ); string strNewColumnName = range.Text.ToString().Trim(); if (strNewColumnName.Length == 0) strNewColumnName = "_1" ; //判断列名是否重复 for ( int i = 1; i < ColumnID; i++) { if (dt.Columns[i - 1].ColumnName == strNewColumnName) strNewColumnName = strNewColumnName + "_1" ; } dc.ColumnName = strNewColumnName; dt.Columns.Add(dc); range = (Excel.Range)worksheet.Cells[1, ++ColumnID]; } //End //数据大于500条,使用多进程进行读取数据 if (iRowCount - 1 > 500) { //开始多线程读取数据 //新建线程 int b2 = (iRowCount - 1) / 10; DataTable dt1 = new DataTable( "dt1" ); dt1 = dt.Clone(); SheetOptions sheet1thread = new SheetOptions(worksheet, iColCount, 2, b2 + 1, dt1); Thread othread1 = new Thread( new ThreadStart(sheet1thread.SheetToDataTable)); othread1.Start(); //阻塞 1 毫秒,保证第一个读取 dt1 Thread.Sleep(1); DataTable dt2 = new DataTable( "dt2" ); dt2 = dt.Clone(); SheetOptions sheet2thread = new SheetOptions(worksheet, iColCount, b2 + 2, b2 * 2 + 1, dt2); Thread othread2 = new Thread( new ThreadStart(sheet2thread.SheetToDataTable)); othread2.Start(); DataTable dt3 = new DataTable( "dt3" ); dt3 = dt.Clone(); SheetOptions sheet3thread = new SheetOptions(worksheet, iColCount, b2 * 2 + 2, b2 * 3 + 1, dt3); Thread othread3 = new Thread( new ThreadStart(sheet3thread.SheetToDataTable)); othread3.Start(); DataTable dt4 = new DataTable( "dt4" ); dt4 = dt.Clone(); SheetOptions sheet4thread = new SheetOptions(worksheet, iColCount, b2 * 3 + 2, b2 * 4 + 1, dt4); Thread othread4 = new Thread( new ThreadStart(sheet4thread.SheetToDataTable)); othread4.Start(); //主线程读取剩余数据 for ( int iRow = b2 * 4 + 2; iRow <= iRowCount; iRow++) { DataRow dr = dt.NewRow(); for ( int iCol = 1; iCol <= iColCount; iCol++) { range = (Excel.Range)worksheet.Cells[iRow, iCol]; cellContent = (range.Value2 == null ) ? "" : range.Text.ToString(); dr[iCol - 1] = cellContent; } dt.Rows.Add(dr); } othread1.Join(); othread2.Join(); othread3.Join(); othread4.Join(); //将多个线程读取出来的数据追加至 dt1 后面 foreach (DataRow dr in dt.Rows) dt1.Rows.Add(dr.ItemArray); dt.Clear(); dt.Dispose(); foreach (DataRow dr in dt2.Rows) dt1.Rows.Add(dr.ItemArray); dt2.Clear(); dt2.Dispose(); foreach (DataRow dr in dt3.Rows) dt1.Rows.Add(dr.ItemArray); dt3.Clear(); dt3.Dispose(); foreach (DataRow dr in dt4.Rows) dt1.Rows.Add(dr.ItemArray); dt4.Clear(); dt4.Dispose(); return dt1; } else { for ( int iRow = 2; iRow <= iRowCount; iRow++) { DataRow dr = dt.NewRow(); for ( int iCol = 1; iCol <= iColCount; iCol++) { range = (Excel.Range)worksheet.Cells[iRow, iCol]; cellContent = (range.Value2 == null ) ? "" : range.Text.ToString(); dr[iCol - 1] = cellContent; } dt.Rows.Add(dr); } } //将数据读入到DataTable中——End return dt; } catch { return null ; } finally { workbook.Close( false , oMissiong, oMissiong); System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook); System.Runtime.InteropServices.Marshal.ReleaseComObject(sheets); workbook = null ; app.Workbooks.Close(); app.Quit(); System.Runtime.InteropServices.Marshal.ReleaseComObject(app); app = null ; GC.Collect(); GC.WaitForPendingFinalizers(); } } |
补充SheetOptions代码:
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class SheetOptions { Microsoft.Office.Interop.Excel.Worksheet worksheet; int iColCount; int star; int end; System.Data.DataTable dt; public SheetOptions(Microsoft.Office.Interop.Excel.Worksheet worksheet, int iColCount, int star, int end, System.Data.DataTable dt) { this .worksheet = worksheet; this .iColCount = iColCount; this .star = star; this .end = end; this .dt = dt; } public void SheetToDataTable() { string cellContent; Microsoft.Office.Interop.Excel.Range range; for ( int iRow = star; iRow <= end; iRow++) { System.Data.DataRow dr = dt.NewRow(); for ( int iCol = 1; iCol <= iColCount; iCol++) { range = (Microsoft.Office.Interop.Excel.Range)worksheet.Cells[iRow, iCol]; cellContent = (range.Value2 == null ) ? "" : range.Text.ToString(); dr[iCol - 1] = cellContent; } dt.Rows.Add(dr); } } } |
原文还提供了第三种方法,感兴趣的可以关心一下:
方法三:NPOI方式读取Excel,NPOI是一组开源的组件,类似Java的 POI。包括:NPOI、NPOI.HPSF、NPOI.HSSF、NPOI.HSSF.UserModel、NPOI.POIFS、NPOI.Util,下载的时候别只下一个噢
优点:读取Excel速度较快,读取方式操作灵活性
缺点:只支持03的Excel,xlsx的无法读取。由于这点,使用这种方式的人不多啊,没理由要求客户使用03版Excel吧,再说03版Excel对于行数还有限制,只支持65536行。
(听他们的开发人员说会在2012年底推出新版,支持xlsx的读取。但一直很忙没时间去关注这个事情,有兴趣的同学可以瞧瞧去)
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using System; using System.Data; using System.IO; using System.Web; using NPOI; using NPOI.HPSF; using NPOI.HSSF; using NPOI.HSSF.UserModel; using NPOI.POIFS; using NPOI.Util; using System.Text; using System.Configuration; public class NPOIHelper { private static int ExcelMaxRow = Convert.ToInt32(ConfigurationManager.AppSettings[ "ExcelMaxRow" ]); /// <summary> /// 由DataSet导出Excel /// </summary> /// <param name="sourceTable">要导出数据的DataTable</param> /// <param name="sheetName">工作表名称</param> /// <returns>Excel工作表</returns> private static Stream ExportDataSetToExcel(DataSet sourceDs) { HSSFWorkbook workbook = new HSSFWorkbook(); MemoryStream ms = new MemoryStream(); for ( int i = 0; i < sourceDs.Tables.Count; i++) { HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet(sourceDs.Tables[i].TableName); HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0); // handling header. foreach (DataColumn column in sourceDs.Tables[i].Columns) headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName); // handling value. int rowIndex = 1; foreach (DataRow row in sourceDs.Tables[i].Rows) { HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex); foreach (DataColumn column in sourceDs.Tables[i].Columns) { dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString()); } rowIndex++; } } workbook.Write(ms); ms.Flush(); ms.Position = 0; workbook = null ; return ms; } /// <summary> /// 由DataSet导出Excel /// </summary> /// <param name="sourceTable">要导出数据的DataTable</param> /// <param name="fileName">指定Excel工作表名称</param> /// <returns>Excel工作表</returns> public static void ExportDataSetToExcel(DataSet sourceDs, string fileName) { //检查是否有Table数量超过65325 for ( int t = 0; t < sourceDs.Tables.Count; t++) { if (sourceDs.Tables[t].Rows.Count > ExcelMaxRow) { DataSet ds = GetdtGroup(sourceDs.Tables[t].Copy()); sourceDs.Tables.RemoveAt(t); //将得到的ds插入 sourceDs中 for ( int g = 0; g < ds.Tables.Count; g++) { DataTable dt = ds.Tables[g].Copy(); sourceDs.Tables.Add(dt); } t--; } } MemoryStream ms = ExportDataSetToExcel(sourceDs) as MemoryStream; HttpContext.Current.Response.AppendHeader( "Content-Disposition" , "attachment;filename=" + fileName); HttpContext.Current.Response.BinaryWrite(ms.ToArray()); HttpContext.Current.ApplicationInstance.CompleteRequest(); //HttpContext.Current.Response.End(); ms.Close(); ms = null ; } /// <summary> /// 由DataTable导出Excel /// </summary> /// <param name="sourceTable">要导出数据的DataTable</param> /// <returns>Excel工作表</returns> private static Stream ExportDataTableToExcel(DataTable sourceTable) { HSSFWorkbook workbook = new HSSFWorkbook(); MemoryStream ms = new MemoryStream(); HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet(sourceTable.TableName); HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0); // handling header. foreach (DataColumn column in sourceTable.Columns) headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName); // handling value. int rowIndex = 1; 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 = 0; sheet = null ; headerRow = null ; workbook = null ; return ms; } /// <summary> /// 由DataTable导出Excel /// </summary> /// <param name="sourceTable">要导出数据的DataTable</param> /// <param name="fileName">指定Excel工作表名称</param> /// <returns>Excel工作表</returns> public static void ExportDataTableToExcel(DataTable sourceTable, string fileName) { //如数据超过65325则分成多个Table导出 if (sourceTable.Rows.Count > ExcelMaxRow) { DataSet ds = GetdtGroup(sourceTable); //导出DataSet ExportDataSetToExcel(ds, fileName); } else { MemoryStream ms = ExportDataTableToExcel(sourceTable) as MemoryStream; HttpContext.Current.Response.AppendHeader( "Content-Disposition" , "attachment;filename=" + fileName); HttpContext.Current.Response.BinaryWrite(ms.ToArray()); HttpContext.Current.ApplicationInstance.CompleteRequest(); //HttpContext.Current.Response.End(); ms.Close(); ms = null ; } } /// <summary> /// 传入行数超过65325的Table,返回DataSet /// </summary> /// <param name="dt"></param> /// <returns></returns> public static DataSet GetdtGroup(DataTable dt) { string tablename = dt.TableName; DataSet ds = new DataSet(); ds.Tables.Add(dt); double n = dt.Rows.Count / Convert.ToDouble(ExcelMaxRow); //创建表 for ( int i = 1; i < n; i++) { DataTable dtAdd = dt.Clone(); dtAdd.TableName = tablename + "_" + i.ToString(); ds.Tables.Add(dtAdd); } //分解数据 for ( int i = 1; i < ds.Tables.Count; i++) { //新表行数达到最大 或 基表数量不足 while (ds.Tables[i].Rows.Count != ExcelMaxRow && ds.Tables[0].Rows.Count != ExcelMaxRow) { ds.Tables[i].Rows.Add(ds.Tables[0].Rows[ExcelMaxRow].ItemArray); ds.Tables[0].Rows.RemoveAt(ExcelMaxRow); } } return ds; } /// <summary> /// 由DataTable导出Excel /// </summary> /// <param name="sourceTable">要导出数据的DataTable</param> /// <param name="fileName">指定Excel工作表名称</param> /// <returns>Excel工作表</returns> public static void ExportDataTableToExcelModel(DataTable sourceTable, string modelpath, string modelName, string fileName, string sheetName) { int rowIndex = 2; //从第二行开始,因为前两行是模板里面的内容 int colIndex = 0; FileStream file = new FileStream(modelpath + modelName + ".xls" , FileMode.Open, FileAccess.Read); //读入excel模板 HSSFWorkbook hssfworkbook = new HSSFWorkbook(file); HSSFSheet sheet1 = (HSSFSheet)hssfworkbook.GetSheet( "Sheet1" ); sheet1.GetRow(0).GetCell(0).SetCellValue( "excelTitle" ); //设置表头 foreach (DataRow row in sourceTable.Rows) { //双循环写入sourceTable中的数据 rowIndex++; colIndex = 0; HSSFRow xlsrow = (HSSFRow)sheet1.CreateRow(rowIndex); foreach (DataColumn col in sourceTable.Columns) { xlsrow.CreateCell(colIndex).SetCellValue(row[col.ColumnName].ToString()); colIndex++; } } sheet1.ForceFormulaRecalculation = true ; FileStream fileS = new FileStream(modelpath + fileName + ".xls" , FileMode.Create); //保存 hssfworkbook.Write(fileS); fileS.Close(); file.Close(); } } |
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原文链接:https://www.cnblogs.com/icyJ/p/ReadExcel.html