.NET读取Excel文件的三种方法的区别

public DataSet ExcelToDS(string Path)  

{   

　　string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" +"Data Source="+ Path +";"+"Extended Properties=Excel 8.0;";

   OleDbConnection conn = new OleDbConnection(strConn);   

　　conn.Open();

   string strExcel = "";

   OleDbDataAdapter myCommand = null;

   DataSet ds = null;

   strExcel="select * from [sheet1$]";

   myCommand = new OleDbDataAdapter(strExcel, strConn);

   ds = new DataSet();    myCommand.Fill(ds,"table1");

   return ds;

}

string strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" +"Data Source="+ Path +";"+"Extended Properties=Excel 8.0;";

OleDbConnection conn = new OleDbConnection(strConn);

DataTable schemaTable = objConn.GetOleDbSchemaTable(System.Data.OleDb.OleDbSchemaGuid.Tables,null);

string tableName=schemaTable.Rows[0][2].ToString().Trim();  

public void DSToExcel(string Path,DataSet oldds)   {   

//先得到汇总Excel的DataSet 主要目的是获得Excel在DataSet中的结构   

string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source ="+path1+";Extended Properties=Excel 8.0" ;

OleDbConnection myConn = new OleDbConnection(strCon) ;

string strCom="select * from [Sheet1$]";

myConn.Open ( ) ;

OleDbDataAdapter myCommand = new OleDbDataAdapter ( strCom, myConn ) ;

ystem.Data.OleDb.OleDbCommandBuilder builder=new OleDbCommandBuilder(myCommand);   

//QuotePrefix和QuoteSuffix主要是对builder生成InsertComment命令时使用。   

builder.QuotePrefix="[";     //获取insert语句中保留字符（起始位置）

builder.QuoteSuffix="]"; //获取insert语句中保留字符（结束位置） 

DataSet newds=new DataSet();

myCommand.Fill(newds ,"Table1") ;

for(int i=0;i<oldds.Tables[0].Rows.Count;i++)   

{    

　　//在这里不能使用ImportRow方法将一行导入到news中，

　　//因为ImportRow将保留原来DataRow的所有设置(DataRowState状态不变)。

　　//在使用ImportRow后newds内有值，但不能更新到Excel中因为所有导入行的DataRowState!=Added

　　DataRow nrow=aDataSet.Tables["Table1"].NewRow();

   for(int j=0;j<newds.Tables[0].Columns.Count;j++)

   {     

　　　　nrow[j]=oldds.Tables[0].Rows[i][j];

   }    

　　　　newds.Tables["Table1"].Rows.Add(nrow);  

}   

myCommand.Update(newds,"Table1");

myConn.Close();

}

//读取EXCEL的方法   (用范围区域读取数据)

private void OpenExcel(string strFileName)  {     

object missing = System.Reflection.Missing.Value;     

Application excel = new Application();//lauch excel application

if (excel == null)    

{       

  Response.Write("<script>alert('Can't access excel')</script>");     

}    

else    

{         

　　excel.Visible = false;

　　excel.UserControl = true;          // 以只读的形式打开EXCEL文件

    Workbook wb = excel.Application.Workbooks.Open(strFileName, missing, true, missing, missing, missing,missing, missing, missing, true, missing, missing, missing, missing, missing);          //取得第一个工作薄 

    Worksheet ws = (Worksheet)wb.Worksheets.get_Item(1);           //取得总记录行数   (包括标题列)   

   int rowsint = ws.UsedRange.Cells.Rows.Count; //得到行数         

　　//int columnsint = mySheet.UsedRange.Cells.Columns.Count;//得到列数          

　　//取得数据范围区域  (不包括标题列)

   Range rng1 = ws.Cells.get_Range("B2", "B" + rowsint);   //item         

   Range rng2 = ws.Cells.get_Range("K2", "K" + rowsint);  //Customer         

　 object[,] arryItem= (object[,])rng1.Value2;   //get range's value        

   object[,] arryCus = (object[,])rng2.Value2;             //将新值赋给一个数组        

   string[,] arry = new string[rowsint-1, 2];         

  for (int i = 1; i <= rowsint-1; i++)        

  {             

　　  //Item_Code列             

　　 arry[i - 1, 0] =arryItem[i, 1].ToString();              //Customer_Name列            

 　　arry[i - 1, 1] = arryCus[i, 1].ToString();       

  }      

  Response.Write(arry[0, 0] + "  /  " + arry[0, 1] + "#" + arry[rowsint - 2, 0] + "  /  " + arry[rowsint - 2, 1]);      }      

  excel.Quit(); 

　excel = null;  

  Process[] procs = Process.GetProcessesByName("excel"); 

foreach (Process pro in procs)     

{         

　　pro.Kill();//没有更好的方法,只有杀掉进程    

}     

GC.Collect(); 

}

using System.Text;和using System.IO;           

FileStream fs = new FileStream("d:\\Customer.csv", FileMode.Open, FileAccess.Read, FileShare.None);

StreamReader sr = new StreamReader(fs, System.Text.Encoding.GetEncoding(936));

string str = "";           

string s = Console.ReadLine();           

while (str != null)           

{   

　　str = sr.ReadLine();

　　string[] xu = new String[2];

　　xu = str.Split(',');

　　string ser = xu[0];

　　string dse = xu[1];

　　if (ser == s)

　　{ 

　　　　Console.WriteLine(dse);break;

　　}          

}  

sr.Close();

//txt文件名 

string fn = DateTime.Now.ToString("yyyyMMddHHmmss") + "-" + "PO014" + ".txt";   OleDbConnection con = new OleDbConnection(conStr);   con.Open();  string sql = "select  ITEM,REQD_DATE,QTY,PUR_FLG,PO_NUM from TSD_PO014";          OleDbCommand mycom = new OleDbCommand("select * from TSD_PO014", mycon); 

//OleDbDataReader myreader = mycom.ExecuteReader();  //也可以用Reader读取数据

DataSet ds = new DataSet(); 

OleDbDataAdapter oda = new OleDbDataAdapter(sql, con);

oda.Fill(ds, "PO014"); 

DataTable dt = ds.Tables[0]; 

FileStream fs = new FileStream(Server.MapPath("download/" + fn), FileMode.Create, FileAccess.ReadWrite); 

StreamWriter strmWriter = new StreamWriter(fs);    //存入到文本文件中   

//把标题写入.txt文件中 

//for (int i = 0; i <dt.Columns.Count;i++) 

//{ 

//    strmWriter.Write(dt.Columns[i].ColumnName + "  ");

//} 

foreach (DataRow dr in dt.Rows) 

{    

　　string str0, str1, str2, str3;     

　　string str = "|";  //数据用"|"分隔开   

　　str0 = dr[0].ToString();     

　　str1 = dr[1].ToString();   

　　str2 = dr[2].ToString(); 

　　str3 = dr[3].ToString();  

   str4 = dr[4].ToString().Trim();  

   strmWriter.Write(str0);  

   strmWriter.Write(str); 

   strmWriter.Write(str1);  

   strmWriter.Write(str); 

   strmWriter.Write(str2);  

   strmWriter.Write(str);  

   strmWriter.Write(str3); 

   strmWriter.WriteLine();  //换行 

} 

strmWriter.Flush();

strmWriter.Close();

if (con.State == ConnectionState.Open) 

{    

　　con.Close();

}