客服电话
APP下载
迪恩网络APP
随时随地掌握行业动态
官方微信
扫描二维码
关注迪恩网络微信公众号
|
参考文章 C#读取Excel的五种方式体会 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。这种方式将Excel作为一个数据源，直接用Sql语句获取数据了。所以读取之前要知道此次要读取的Sheet（当然也可以用序号，类似dt.Row[0][0]。这样倒是不需要知道Sheet）. if (fileType == ".xls")
connStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + fileName + ";" + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\"";
else
connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + fileName + ";" + ";Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"";
OleDbConnection conn = new OleDbConnection(connStr);
DataTable dtSheetName = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
以上是读取Excel的Sheet名，xls和xlsx的连接字符串也不一样的，可以根据文件的后缀来区别。这里需要注意的一点，Excel里面只有一个Sheet，但通过这种方式读取Sheet可能会大于一个。 在使用过程中发现取出的Sheet和实际excel不一致， 会多出不少。目前总结后有两种情况： 1. 取出的名称中，包括了XL命名管理器中的名称（参见XL2007的公式的命名管理器，【Crtl+F3】）； 2. 取出的名称中，包括了FilterDatabase后缀。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，当时还是有点问题，本来补充了一点。总之先看代码吧： for (int i = 0; i < dtSheetName.Rows.Count; i++) { SheetName = (string)dtSheetName.Rows[i]["TABLE_NAME"]; if (SheetName .Contains("$") && !SheetName .Replace("'", "").EndsWith("$")) continue; //过滤无效SheetName完毕.... da.SelectCommand = new OleDbCommand(String.Format(sql_F, tblName), conn); DataSet dsItem = new DataSet(); da.Fill(dsItem, tblName); } 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$之前最好过滤一下单引号。 优点：读取方式简单、读取速度快 缺点：除了读取过程不太灵活之外，这种读取方式还有个弊端就是，当Excel数据量很大时。会非常占用内存，当内存不够时会抛出内存溢出的异常。 不过一般情况下还是非常不错的，以下是完整代码。 /// <summary> /// 读取Excel文件到DataSet中 /// </summary> /// <param name="filePath">文件路径</param> /// <returns></returns> public static DataSet ToDataTable(string filePath) { string connStr = ""; string fileType = System.IO.Path.GetExtension(fileName); if (string.IsNullOrEmpty(fileType)) return null; if (fileType == ".xls") connStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + filePath+ ";" + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\""; else connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + filePath+ ";" + ";Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\""; string sql_F = "Select * FROM [{0}]"; OleDbConnection conn = null; OleDbDataAdapter da = null; DataTable dtSheetName= null; DataSet ds = new DataSet(); try { // 初始化连接，并打开 conn = new OleDbConnection(connStr); conn.Open(); // 获取数据源的表定义元数据 string SheetName = ""; dtSheetName= conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" }); // 初始化适配器 da = new OleDbDataAdapter(); for (int i = 0; i < dtSheetName.Rows.Count; i++) { SheetName = (string)dtSheetName.Rows[i]["TABLE_NAME"]; if (SheetName .Contains("$") && !SheetName .Replace("'", "").EndsWith("$")) { continue; } da.SelectCommand = new OleDbCommand(String.Format(sql_F, SheetName ), conn); DataSet dsItem = new DataSet(); da.Fill(dsItem, tblName); ds.Tables.Add(dsItem.Tables[0].Copy()); } } catch (Exception ex) { } finally { // 关闭连接 if (conn.State == ConnectionState.Open) { conn.Close(); da.Dispose(); conn.Dispose(); } } return ds; }
2、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。。。 public class ExcelOptions { private Stopwatch wath = new Stopwatch(); /// <summary> /// 使用COM读取Excel /// </summary> /// <param name="excelFilePath">路径</param> /// <returns>DataTabel</returns> public System.Data.DataTable GetExcelData(string excelFilePath) { Excel.Application app = new Excel.Application(); Excel.Sheets sheets; Excel.Workbook workbook = null; object oMissiong = System.Reflection.Missing.Value; System.Data.DataTable dt = new System.Data.DataTable(); wath.Start(); 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() != "") { dc = new DataColumn(); dc.DataType = System.Type.GetType("System.String"); dc.ColumnName = range.Text.ToString().Trim(); dt.Columns.Add(dc); range = (Excel.Range)worksheet.Cells[1, ++ColumnID]; } //End 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(); //if (iRow == 1) //{ // dt.Columns.Add(cellContent); //} //else //{ dr[iCol - 1] = cellContent; //} } //if (iRow != 1) dt.Rows.Add(dr); } wath.Stop(); TimeSpan ts = wath.Elapsed; //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); workbook = null; app.Workbooks.Close(); app.Quit(); System.Runtime.InteropServices.Marshal.ReleaseComObject(app); app = null; GC.Collect(); GC.WaitForPendingFinalizers(); } } /// <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(); wath.Start(); 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); } } wath.Stop(); TimeSpan ts = wath.Elapsed; //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(); /* object objmissing = System.Reflection.Missing.Value; Excel.ApplicationClass application = new ApplicationClass(); Excel.Workbook book = application.Workbooks.Add(objmissing); Excel.Worksheet sheet = (Excel.Worksheet)book.Worksheets.Add（objmissing,objmissing,objmissing,objmissing); //操作过程 ^&%&×&……&%&&…… //释放 sheet.SaveAs(path,objmissing,objmissing,objmissing,objmissing,objmissing,objmissing,objmissing,objmissing); System.Runtime.InteropServices.Marshal.ReleaseComObject((object)sheet); System.Runtime.InteropServices.Marshal.ReleaseComObject((object)book); application.Quit(); System.Runtime.InteropServices.Marshal.ReleaseComObject((object)application); System.GC.Collect(); */ } } /// <summary> /// 删除Excel行 /// </summary> /// <param name="excelFilePath">Excel路径</param> /// <param name="rowStart">开始行</param> /// <param name="rowEnd">结束行</param> /// <param name="designationRow">指定行</param> /// <returns></returns> public string DeleteRows(string excelFilePath, int rowStart, int rowEnd, int designationRow) { string result = ""; Excel.Application app = new Excel.Application(); Excel.Sheets sheets; Excel.Workbook workbook = null; object oMissiong = System.Reflection.Missing.Value; try { if (app == null) { return "分段读取Excel失败"; } workbook = app.Workbooks.Open(excelFilePath, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong); sheets = workbook.Worksheets; Excel.Worksheet worksheet = (Excel.Worksheet)sheets.get_Item(1);//读取第一张表 if (worksheet == null) return result; Excel.Range range; //先删除指定行，一般为列描述 if (designationRow != -1) { range = (Excel.Range)worksheet.Rows[designationRow, oMissiong]; range.Delete(Excel.XlDeleteShiftDirection.xlShiftUp); } Stopwatch sw = new Stopwatch(); sw.Start(); int i = rowStart; for (int iRow = rowStart; iRow <= rowEnd; iRow++, i++) { range = (Excel.Range)worksheet.Rows[rowStart, oMissiong]; range.Delete(Excel.XlDeleteShiftDirection.xlShiftUp); } sw.Stop(); TimeSpan ts = sw.Elapsed; workbook.Save(); //将数据读入到DataTable中——End return result; } catch { return "分段读取Excel失败"; } 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; GC.Collect(); GC.WaitForPendingFinalizers(); } } public void ToExcelSheet(DataSet ds, string fileName) { Excel.Application appExcel = new Excel.Application(); Excel.Workbook workbookData = null; Excel.Worksheet worksheetData; Excel.Range range; try { workbookData = appExcel.Workbooks.Add(System.Reflection.Missing.Value); appExcel.DisplayAlerts = false;//不显示警告 //xlApp.Visible = true;//excel是否可见 // //for (int i = workbookData.Worksheets.Count; i > 0; i--) //{ // Microsoft.Office.Interop.Excel.Worksheet oWorksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbookData.Worksheets.get_Item(i); // oWorksheet.Select(); // oWorksheet.Delete(); //} for (int k = 0; k < ds.Tables.Count; k++) { worksheetData = (Excel.Worksheet)workbookData.Worksheets.Add(System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value); // testnum--; if (ds.Tables[k] != null) { worksheetData.Name = ds.Tables[k].TableName; //写入标题 for (int i = 0; i < ds.Tables[k].Columns.Count; i++) { worksheetData.Cells[1, i + 1] = ds.Tables[k].Columns[i].ColumnName; range = (Excel.Range)worksheetData.Cells[1, i + 1]; //range.Interior.ColorIndex = 15; range.Font.Bold = true; range.NumberFormatLocal = "@";//文本格式 range.EntireColumn.AutoFit();//自动调整列宽 // range.WrapText = true; //文本自动换行 range.ColumnWidth = 15; } //写入数值 for (int r = 0; r < ds.Tables[k].Rows.Count; r++) { for (int i = 0; i < ds.Tables[k].Columns.Count; i++) { worksheetData.Cells[r + 2, i + 1] = ds.Tables[k].Rows[r][i]; //Range myrange = worksheetData.get_Range(worksheetData.Cells[r + 2, i + 1], worksheetData.Cells[r + 3, i + 2]); //myrange.NumberFormatLocal = "@";//文本格式 //// myrange.EntireColumn.AutoFit();//自动调整列宽 //// myrange.WrapText = true; //文本自动换行 //myrange.ColumnWidth = 15; } // rowRead++; //System.Windows.Forms.Application.DoEvents(); } } worksheetData.Columns.EntireColumn.AutoFit(); workbookData.Saved = true; } } catch (Exception ex) { } finally { workbookData.SaveCopyAs(fileName); workbookData.Close(false, System.Reflection.Missing.Value, System.Reflection.Missing.Value); appExcel.Quit(); GC.Collect(); } } }
3、NPOI方式读取ExcelNPOI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） 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 = |
2023-10-27
2022-08-15
2022-08-17
2022-09-23
2022-08-13
六六分期app的软件客服如何联系？不知道吗？加qq群【895510560】即可！标题：六六分期
今天小编告诉大家如何处理win10系统火狐flash插件总是崩溃的问题，可能很多用户都不知
今天小编告诉大家如何对win10系统删除桌面回收站图标进行设置，可能很多用户都不知道
今天小编告诉大家如何对win10系统电脑设置节能降温的设置方法，想必大家都遇到过需要
我们在使用xp系统的过程中,经常需要对xp系统无线网络安装向导设置进行设置，可能很多
今天小编告诉大家如何处理win7系统玩cf老是与主机连接不稳定的问题，可能很多用户都不
电脑对日常生活的重要性小编就不多说了，可是一旦碰到win7系统设置cf烟雾头的问题，很
我们在日常使用电脑的时候，有的小伙伴们可能在打开应用的时候会遇见提示应用程序无法
今天小编告诉大家如何对win7系统打开vcf文件进行设置，可能很多用户都不知道怎么对win
今天小编告诉大家如何对win10系统s4开启USB调试模式进行设置，可能很多用户都不知道怎
请发表评论