C#Excel数据导入导出方法总结

一.OLEDB

1.导入：

 public DataSet ExcelToDS(string Path, string name)
        {
            FileInfo file = new FileInfo(Path);
            string extension = file.Extension;
            string strConn = "";
            switch (extension)
            {
                case ".xls":
                    strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Path + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
                    break;
                case ".xlsx":
                    strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Path + ";Extended Properties='Excel 12.0;HDR=YES;IMEX=1;'";
                    break;
                default:
                    strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Path + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
                    break;
            }

            //ModifyRegeditTypeGuessRow(0);

            OleDbConnection conn = new OleDbConnection(strConn);
            conn.Open();
            System.Data.DataTable sTable = conn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null);
            //Sheets Name

            name = name + "$";
            string strExcel = "";
            OleDbDataAdapter myCommand = null;
            DataSet ds = null;
            strExcel = "select * from [" + name + "]";
            myCommand = new OleDbDataAdapter(strExcel, strConn);
            ds = new DataSet();
            myCommand.Fill(ds, "RecordTable");
            conn.Close();
            if(name.Equals("记录表$"))
            {
                DataTable dt = ImportExcelFile(Path);
                ReplaceWorkMatter(ds,dt);
            }
            
            return ds;
        }
2.导出：

 public DataSet ExcelToDS(string Path, int i)
        {
            FileInfo file = new FileInfo(Path);
            string extension = file.Extension;
            string strConn = "";
            switch (extension)
            {
                case ".xls":
                    strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Path + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
                    break;
                case ".xlsx":
                    strConn = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Path + ";Extended Properties='Excel 12.0;HDR=YES;IMEX=1;'";
                    break;
                default:
                    strConn = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Path + ";Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
                    break;
            }
            //ModifyRegeditTypeGuessRow(0);

            OleDbConnection conn = new OleDbConnection(strConn);
            conn.Open();
            System.Data.DataTable sTable = conn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables, null);
            //Sheets Name
            string tableName = sTable.Rows[i][2].ToString().Trim();
            if (tableName == "")
            {
                return null;
            }
            else
            {
                tableName = "[" + tableName + "]";
            }
            string strExcel = "";
            OleDbDataAdapter myCommand = null;
            DataSet ds = null;
            strExcel = "select * from " + tableName;
            myCommand = new OleDbDataAdapter(strExcel, strConn);
            ds = new DataSet();
            myCommand.Fill(ds, "RecordTable");
            conn.Close();
            //if (i==0)
            //{
            //    DataTable dt = ImportExcelFile(Path);
            //    ReplaceWorkMatter(ds, dt);
            //}
           
            return ds;
        }
	
  
    
    
    
    

   	使用这种方法时，曾经遇到过Excel的某列前面部分是数字，后面部分是字符。通过这种方法导入的时候发现后面字符部分的数据并没有导入。还有，使用“不包含表头的连接”时，在Excel中某一行是列名行（列名一般是字符），而该列的值若是数字或日期等，导入DataTable时，列名无法导入。调试后发现，导入的时候，系统会根据Excel里面的内容为DataTable的列设置类型。前面是数字，这一列就是整型的了，后面的字符当然导不进去了。
  
    
    
    
    
  
    
    
    
    

     
     
     
     
    
  
    
    
    
    
  
    
    
    
    

     
     
     
     
   IMEX是用来告诉驱动程序使用Excel文件的模式，其值有0、1、2三种，分别代表导出、导入、混合模式。当我们设置IMEX＝1时将强制混合数据转换为文本，但仅仅这种设置并不可靠，IMEX＝1只确保在某列前8行数据至少有一个是文本项的时候才起作用，它只是把查找前8行数据中数据类型占优选择的行为作了略微的改变。例如某列前8行数据全为纯数字，那么它仍然以数字类型作为该列的数据类型，随后行里的含有文本的数据仍然变空。 
   
     
     
     
     
另一个改进的措施是IMEX＝1与注册表值TypeGuessRows配合使用，TypeGuessRows 值决定了ISAM 驱动程序从前几条数据采样确定数据类型，默认为“8”。可以通过修改“HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\4.0\Engines\Excel”下的该注册表值来更改采样行数。（http://liweibird.blog.51cto.com/631764/274434）
  
    
    
    
    

二.NOPI方式

    使用此方式效率高，避免了OLEDB的数据截断，不依赖于系统Offic

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using NPOI.SS.UserModel;        //NPOI
using NPOI.HSSF.Util;           //NPOI
using NPOI.HSSF.UserModel;      //NPOI
using NPOI.XSSF.UserModel;      //NPOI
using System.Data.SqlClient;
using System.Data;

 

1.导入

/// 

/// Excel某sheet中内容导入到DataTable中
/// 区分xsl和xslx分别处理
/// 
/// Excel文件路径,含文件全名
/// 此Excel中sheet名
/// 
public DataTable ExcelSheetImportToDataTable(string filePath, string sheetName)
{
            
    DataTable dt = new DataTable();

    if (Path.GetExtension(filePath).ToLower() == ".xls".ToLower())
    {//.xls
        #region .xls文件处理:HSSFWorkbook
        try
        {
            using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
            {

                hssfworkbook = new HSSFWorkbook(file);
            }
        }
        catch (Exception e)
        {
            throw e;
        }            

        ISheet sheet = hssfworkbook.GetSheet(sheetName);
        System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
        HSSFRow headerRow = (HSSFRow)sheet.GetRow(0);                

        //一行最后一个方格的编号 即总的列数  
        for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
        {
            //SET EVERY COLUMN NAME
            HSSFCell cell = (HSSFCell)headerRow.GetCell(j);

            dt.Columns.Add(cell.ToString());
        }

        while (rows.MoveNext())
        {
            IRow row = (HSSFRow)rows.Current;
            DataRow dr = dt.NewRow();

            if (row.RowNum == 0) continue;//The firt row is title,no need import

            for (int i = 0; i < row.LastCellNum; i++)
            {
                if (i>=dt.Columns.Count)//cell count>column count,then break //每条记录的单元格数量不能大于表格栏位数量 20140213
                {
                    break;
                }

                ICell cell = row.GetCell(i);

                if ((i==0)&&(string.IsNullOrEmpty(cell.ToString())==true))//每行第一个cell为空,break
                {
                    break;
                }

                if (cell == null)
                {
                    dr[i] = null;
                }
                else
                {
                    dr[i] = cell.ToString();
                }
            }
                    
            dt.Rows.Add(dr);
        }
        #endregion
    }
    else
    {//.xlsx
        #region .xlsx文件处理:XSSFWorkbook
        try
        {
            using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
            {

                hssfworkbook = new XSSFWorkbook(file);
            }
        }
        catch (Exception e)
        {
            throw e;
        }            

        ISheet sheet = hssfworkbook.GetSheet(sheetName);
        System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
        XSSFRow headerRow = (XSSFRow)sheet.GetRow(0);

                

        //一行最后一个方格的编号 即总的列数  
        for (int j = 0; j < (sheet.GetRow(0).LastCellNum); j++)
        {
            //SET EVERY COLUMN NAME
            XSSFCell cell = (XSSFCell)headerRow.GetCell(j);

            dt.Columns.Add(cell.ToString());

        }

        while (rows.MoveNext())
        {
            IRow row = (XSSFRow)rows.Current;
            DataRow dr = dt.NewRow();

            if (row.RowNum == 0) continue;//The firt row is title,no need import

            for (int i = 0; i < row.LastCellNum; i++)
            {
                if (i >= dt.Columns.Count)//cell count>column count,then break //每条记录的单元格数量不能大于表格栏位数量 20140213
                {
                    break;
                }

                ICell cell = row.GetCell(i);

                if ((i == 0) && (string.IsNullOrEmpty(cell.ToString()) == true))//每行第一个cell为空,break
                {
                    break;
                }

                if (cell == null)
                {
                    dr[i] = null;
                }
                else
                {
                    dr[i] = cell.ToString();
                }
            }
            dt.Rows.Add(dr);
        }
        #endregion
    }
    return dt;
}

 2.导出

 /// 

        /// NPOI导出Excel，不依赖本地是否装有Excel，导出速度快
        /// 
        /// 要导出的dataGridView控件
        /// sheet表名
        /// 
        public static void ExportToExcel(DataGridView dataGridView1, string sheetName)
        {
            SaveFileDialog fileDialog = new SaveFileDialog();
            fileDialog.Filter = "Excel(97-2003)|*.xls";
            if (fileDialog.ShowDialog() == System.Windows.Forms.DialogResult.Cancel)
            {
                return;
            }
            //不允许dataGridView显示添加行，负责导出时会报最后一行未实例化错误
            dataGridView1.AllowUserToAddRows = false;
            HSSFWorkbook workbook = new HSSFWorkbook();
            ISheet sheet = workbook.CreateSheet(sheetName);
            IRow rowHead = sheet.CreateRow(0);

            //填写表头
            for (int i = 0; i < dataGridView1.Columns.Count; i++)
            {
                rowHead.CreateCell(i, CellType.String).SetCellValue(dataGridView1.Columns[i].HeaderText.ToString());
            }
            //填写内容
            for (int i = 0; i < dataGridView1.Rows.Count; i++)
            {
                IRow row = sheet.CreateRow(i + 1);
                for (int j = 0; j < dataGridView1.Columns.Count; j++)
                {
                    row.CreateCell(j, CellType.String).SetCellValue(dataGridView1.Rows[i].Cells[j].Value.ToString());
                }
            }

            using (FileStream stream = File.OpenWrite(fileDialog.FileName))
            {
                workbook.Write(stream);
                stream.Close();
            }
            MessageBox.Show("导出数据成功!", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            GC.Collect();
        }