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C#读取Excel技术概览

原作者: [db:作者] 来自: [db:来源] 收藏邀请

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);  
}

View Code

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;  
        }

读取Excel完整代码

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();  
            }  
        }  
       
    }

单线程和多线程读取类

3、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）

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 =