DataTable中的数据导出Excel文件

/// <summary>
 /// 将DataTable中的数据导出到指定的Excel文件中
 /// </summary>
 /// <param name="page">Web页面对象</param>
 /// <param name="tab">包含被导出数据的DataTable对象</param>
 /// <param name="FileName">Excel文件的名称</param>
 public static void Export(System.Web.UI.Page page,System.Data.DataTable tab,string FileName)
 {
 System.Web.HttpResponse httpResponse = page.Response;
 System.Web.UI.WebControls.DataGrid dataGrid=new System.Web.UI.WebControls.DataGrid();
 dataGrid.DataSource=tab.DefaultView;
 dataGrid.AllowPaging = false;
 dataGrid.HeaderStyle.BackColor = System.Drawing.Color.Green;
 dataGrid.HeaderStyle.HorizontalAlign = HorizontalAlign.Center;
 dataGrid.HeaderStyle.Font.Bold = true;
 dataGrid.DataBind();
 httpResponse.AppendHeader("Content-Disposition","attachment;filename="+HttpUtility.UrlEncode(FileName,System.Text.Encoding.UTF8)); //filename="*.xls";
 httpResponse.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");
 httpResponse.ContentType ="application/ms-excel";
 System.IO.StringWriter tw = new System.IO.StringWriter() ;
 System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter (tw);
 dataGrid.RenderControl(hw);

 string filePath = page.Server.MapPath("..")+"\\Files\\" +FileName;
 System.IO.StreamWriter sw = System.IO.File.CreateText(filePath);
 sw.Write(tw.ToString());
 sw.Close();

DownFile(httpResponse,FileName,filePath);

 httpResponse.End();
 }
private static bool DownFile(System.Web.HttpResponse Response,string fileName,string fullPath)
 {
 try
 {
 Response.ContentType = "application/octet-stream";

 Response.AppendHeader("Content-Disposition","attachment;filename=" +
 HttpUtility.UrlEncode(fileName,System.Text.Encoding.UTF8) + ";charset=GB2312");
 System.IO.FileStream fs= System.IO.File.OpenRead(fullPath);
 long fLen=fs.Length;
 int size=102400;//每100K同时下载数据
 byte[] readData = new byte[size];//指定缓冲区的大小
 if(size>fLen)size=Convert.ToInt32(fLen);
 long fPos=0;
 bool isEnd=false;
 while (!isEnd)
 {
 if((fPos+size)>fLen)
 {
 size=Convert.ToInt32(fLen-fPos);
 readData = new byte[size];
 isEnd=true;
 }
 fs.Read(readData, 0, size);//读入一个压缩块
 Response.BinaryWrite(readData);
 fPos+=size;
 }
 fs.Close();
 System.IO.File.Delete(fullPath);
 return true;
 }
 catch
 {
 return false;
 }
 }

将指定Excel文件中的数据转换成DataTable
/// <summary>
 /// 将指定Excel文件中的数据转换成DataTable对象，供应用程序进一步处理
 /// </summary>
 /// <param name="filePath"></param>
 /// <returns></returns>
 public static System.Data.DataTable Import(string filePath)
 {
 System.Data.DataTable rs = new System.Data.DataTable();
 bool canOpen=false;

 OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;"+
 "Data Source=" + filePath + ";" +
 "Extended Properties=\"Excel 8.0;\"");

 try//尝试数据连接是否可用
 {
 conn.Open();
 conn.Close();
 canOpen=true;
 }
 catch{}

if(canOpen)
 {
 try//如果数据连接可以打开则尝试读入数据
 {
 OleDbCommand myOleDbCommand = new OleDbCommand("SELECT * FROM [Sheet1$]",conn);
 OleDbDataAdapter myData = new OleDbDataAdapter(myOleDbCommand);
 myData.Fill(rs);
 conn.Close();
 }
 catch//如果数据连接可以打开但是读入数据失败，则从文件中提取出工作表的名称，再读入数据
 {
 string sheetName=GetSheetName(filePath);
 if(sheetName.Length>0)
 {
 OleDbCommand myOleDbCommand = new OleDbCommand("SELECT * FROM ["+sheetName+"$]",conn);
 OleDbDataAdapter myData = new OleDbDataAdapter(myOleDbCommand);
 myData.Fill(rs);
 conn.Close();
 }
 }
 }
 else
 {
 System.IO.StreamReader tmpStream=File.OpenText(filePath);
 string tmpStr=tmpStream.ReadToEnd();
 tmpStream.Close();
 rs=GetDataTableFromString(tmpStr);
 tmpStr="";
 }
 return rs;
 }
/// <summary>
 /// 将指定Html字符串的数据转换成DataTable对象 --根据“<tr><td>”等特殊字符进行处理
 /// </summary>
 /// <param name="tmpHtml">Html字符串</param>
 /// <returns></returns>
 private static DataTable GetDataTableFromString(string tmpHtml)
 {
 string tmpStr=tmpHtml;
 DataTable TB=new DataTable();
 //先处理一下这个字符串，删除第一个<tr>之前合最后一个</tr>之后的部分
 int index=tmpStr.IndexOf("<tr");
 if(index>-1)
 tmpStr=tmpStr.Substring(index);
 else
 return TB;

index=tmpStr.LastIndexOf("</tr>");
 if(index>-1)
 tmpStr=tmpStr.Substring(0,index+5);
 else
 return TB;

bool existsSparator=false;
char Separator=Convert.ToChar("^");

    //如果原字符串中包含分隔符“^”则先把它替换掉
    if(tmpStr.IndexOf(Separator.ToString())>-1)
    {
     existsSparator=true;
     tmpStr=tmpStr.Replace("^","^$&^");
    }

//先根据“</tr>”分拆
string[] tmpRow=tmpStr.Replace("</tr>","^").Split(Separator);

for(int i=0;i<tmpRow.Length-1;i++)
 {
 DataRow newRow=TB.NewRow();

string tmpStrI=tmpRow[i];
 if(tmpStrI.IndexOf("<tr")>-1)
 {
 tmpStrI=tmpStrI.Substring(tmpStrI.IndexOf("<tr"));
 if(tmpStrI.IndexOf("display:none")<0||tmpStrI.IndexOf("display:none")>tmpStrI.IndexOf(">"))
 {
 tmpStrI=tmpStrI.Replace("</td>","^");
 string[] tmpField=tmpStrI.Split(Separator);

 for(int j=0;j<tmpField.Length-1;j++)
 {
 tmpField[j]=RemoveString(tmpField[j],"");
 index=tmpField[j].LastIndexOf(">")+1;
 if(index>0)
 {
 string field=tmpField[j].Substring(index,tmpField[j].Length-index);
 if(existsSparator) field=field.Replace("^$&^","^");
 if(i==0)
 {
 string tmpFieldName=field;
 int sn=1;
 while(TB.Columns.Contains(tmpFieldName))
 {
 tmpFieldName=field+sn.ToString();
 sn+=1;
 }
 TB.Columns.Add(tmpFieldName);
 }
 else
 {
 newRow[j]=field;
 }
 }//end of if(index>0)
 }

       if(i>0)
        TB.Rows.Add(newRow);
      }
     }
    }

    TB.AcceptChanges();
    return TB;
   }

/// <summary>
 /// 从指定Html字符串中剔除指定的对象
 /// </summary>
 /// <param name="tmpHtml">Html字符串</param>
 /// <param name="remove">需要剔除的对象--例如输入""则剔除""和">"</param>
 /// <returns></returns>
 public static string RemoveString(string tmpHtml,string remove)
 {
 tmpHtml=tmpHtml.Replace(remove.Replace("<","</"),"");
 tmpHtml=RemoveStringHead(tmpHtml,remove);
 return tmpHtml;
 }
 /// <summary>
 /// 只供方法RemoveString()使用
 /// </summary>
 /// <returns></returns>
 private static string RemoveStringHead(string tmpHtml,string remove)
 {
 //为了方便注释，假设输入参数remove=""
 if(remove.Length<1) return tmpHtml;//参数remove为空：不处理返回
 if((remove.Substring(0,1)!="<")||(remove.Substring(remove.Length-1)!=">")) return tmpHtml;//参数remove不是<?????>：不处理返回

int IndexS=tmpHtml.IndexOf(remove.Replace(">",""));//查找“<font”的位置
 int IndexE=-1;
 if(IndexS>-1)
 {
 string tmpRight=tmpHtml.Substring(IndexS,tmpHtml.Length-IndexS);
 IndexE=tmpRight.IndexOf(">");
 if(IndexE>-1)
 tmpHtml=tmpHtml.Substring(0,IndexS)+tmpHtml.Substring(IndexS+IndexE+1);
 if(tmpHtml.IndexOf(remove.Replace(">",""))>-1)
 tmpHtml=RemoveStringHead(tmpHtml,remove);
 }
 return tmpHtml;
 }

/// <summary>
 /// 将指定Excel文件中读取第一张工作表的名称
 /// </summary>
 /// <param name="filePath"></param>
 /// <returns></returns>
 private static string GetSheetName(string filePath)
 {
 string sheetName="";

    System.IO.FileStream tmpStream=File.OpenRead(filePath);
    byte[] fileByte=new byte[tmpStream.Length];
    tmpStream.Read(fileByte,0,fileByte.Length);
    tmpStream.Close();

    byte[] tmpByte=new byte[]{Convert.ToByte(11),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),
           Convert.ToByte(11),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),Convert.ToByte(0),
           Convert.ToByte(30),Convert.ToByte(16),Convert.ToByte(0),Convert.ToByte(0)};

    int index=GetSheetIndex(fileByte,tmpByte);
    if(index>-1)
    {

index+=16+12;
 System.Collections.ArrayList sheetNameList=new System.Collections.ArrayList();

 for(int i=index;i<fileByte.Length-1;i++)
 {
 byte temp=fileByte[i];
 if(temp!=Convert.ToByte(0))
 sheetNameList.Add(temp);
 else
 break;
 }
 byte[] sheetNameByte=new byte[sheetNameList.Count];
 for(int i=0;i<sheetNameList.Count;i++)
 sheetNameByte[i]=Convert.ToByte(sheetNameList[i]);

 sheetName=System.Text.Encoding.Default.GetString(sheetNameByte);
 }
 return sheetName;
 }
 /// <summary>
 /// 只供方法GetSheetName()使用
 /// </summary>
 /// <returns></returns>
 private static int GetSheetIndex(byte[] FindTarget,byte[] FindItem)
 {
 int index=-1;

int FindItemLength=FindItem.Length;
 if(FindItemLength<1) return -1;
 int FindTargetLength=FindTarget.Length;
 if((FindTargetLength-1)<FindItemLength) return -1;

for(int i=FindTargetLength-FindItemLength-1;i>-1;i--)
 {
 System.Collections.ArrayList tmpList=new System.Collections.ArrayList();
 int find=0;
 for(int j=0;j<FindItemLength;j++)
 {
 if(FindTarget[i+j]==FindItem[j]) find+=1;
 }
 if(find==FindItemLength)
 {
 index=i;
 break;
 }
 }
 return index;
 }