文件下载
文件下载
public
static
bool
ResponseFile(HttpRequest _Request, HttpResponse _Response,
string
_fileName,
string
_fullPath,
long
_speed)
{
try
{
FileStream myFile
=
new
FileStream(_fullPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
BinaryReader br
=
new
BinaryReader(myFile);
try
{
_Response.AddHeader(
"
Accept-Ranges
"
,
"
bytes
"
);
_Response.Buffer
=
false
;
long
fileLength
=
myFile.Length;
long
startBytes
=
0
;
double
pack
=
10240
;
//
10K bytes
//
int sleep = 200;
//
每秒5次 即5*10K bytes每秒
int
sleep
=
(
int
)Math.Floor(
1000
*
pack
/
_speed)
+
1
;
if
(_Request.Headers[
"
Range
"
]
!=
null
)
{
_Response.StatusCode
=
206
;
string
[] range
=
_Request.Headers[
"
Range
"
].Split(
new
char
[] {
'
=
'
,
'
-
'
});
startBytes
=
Convert.ToInt64(range[
1
]);
}
_Response.AddHeader(
"
Content-Length
"
, (fileLength
-
startBytes).ToString());
if
(startBytes
!=
0
)
{
//
Response.AddHeader("Content-Range", string.Format(" bytes {0}-{1}/{2}", startBytes, fileLength-1, fileLength));
}
_Response.AddHeader(
"
Connection
"
,
"
Keep-Alive
"
);
_Response.ContentType
=
"
application/octet-stream;charset=gbk
"
;
_Response.AddHeader(
"
Content-Disposition
"
,
"
attachment;filename=
"
+
HttpUtility.UrlEncode(_fileName, System.Text.Encoding.UTF8));
br.BaseStream.Seek(startBytes, SeekOrigin.Begin);
int
maxCount
=
(
int
)Math.Floor((fileLength
-
startBytes)
/
pack)
+
1
;
for
(
int
i
=
0
; i
<
maxCount; i
++
)
{
if
(_Response.IsClientConnected)
{
_Response.BinaryWrite(br.ReadBytes(
int
.Parse(pack.ToString())));
Thread.Sleep(sleep);
}
else
{
i
=
maxCount;
}
}
}
catch
{
return
false
;
}
finally
{
br.Close();
myFile.Close();
}
}
catch
{
return
false
;
}
return
true
;
}
调用方法
ExportExcel excel
=
new
ExportExcel();
string
fileName
=
excel.Export(dt,
"
项目统计
"
, DataName);
string
path
=
Request.PhysicalApplicationPath
+
"
Excel\\
"
+
fileName
+
"
.xls
"
;
DownFile.ResponseFile(Page.Request, Page.Response, fileName
+
"
.xls
"
, path,
1024000
);
没搞清楚到底是什么原理，留下，等以后研究。