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],"<font>");
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"<font>"则剔除"<font ???????>"和"</font>>"</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="<font>"
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;
}