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
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）
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）
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。)：
/// <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：
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）
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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