private void Export(System.Web.UI.WebControls.DataGrid dg,string fileName,string typeName)
...{
System.Web.HttpResponse httpResponse = Page.Response;
httpResponse.AppendHeader
("Content-Disposition","attachment;filename="
+HttpUtility.UrlEncode(fileName,System.Text.Encoding.UTF8));
httpResponse.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");
httpResponse.ContentType = typeName;
System.IO.StringWriter tw = new System.IO.StringWriter() ;
System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter (tw);
dg.RenderControl(hw);
string filePath = Server.MapPath("..")+fileName;
System.IO.StreamWriter sw = System.IO.File.CreateText(filePath);
sw.Write(tw.ToString());
sw.Close();

DownFile(httpResponse,fileName,filePath);
httpResponse.End();
}

private 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;
}
}
}

为了方便大家Copy可以
看如下的代码,保证一样的

private void Export(System.Web.UI.WebControls.DataGrid dg,string fileName,string typeName)
{
System.Web.HttpResponse httpResponse = Page.Response;
httpResponse.AppendHeader("Content-Disposition","attachment;filename="+HttpUtility.UrlEncode(fileName,System.Text.Encoding.UTF8));
httpResponse.ContentEncoding=System.Text.Encoding.GetEncoding("GB2312");
httpResponse.ContentType = typeName;
System.IO.StringWriter tw = new System.IO.StringWriter() ;
System.Web.UI.HtmlTextWriter hw = new System.Web.UI.HtmlTextWriter (tw);
dg.RenderControl(hw);
string filePath = Server.MapPath("..")+fileName;
System.IO.StreamWriter sw = System.IO.File.CreateText(filePath);
sw.Write(tw.ToString());
sw.Close();

DownFile(httpResponse,fileName,filePath);
httpResponse.End();
}

private 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;
}
}[@more@]