我正在尝试创建一个测试页面，其中包含一个HTML5 VIDEO标签，可以播放转换后的视频。我成功地将视频转换并在服务器上本地存储，但我希望能够通过另一个.aspx页面传输所有视频。
假设我有一个包含HTML代码和getvideo.aspx页面的player.aspx页面除了提供视频二进制文件之外什么都不做，我认为以下代码在我的player.aspx页面中可以正常工作：
<div style="text-align:center">
<video controls autoplay id="video1" width="920">
<source src="http://www.mywebsite.com/getvideo.aspx?getvideo=1" type="video/mp4">
Your browser does not support HTML5 video.
</video>
getvideo.aspx页面包含以下vb.net代码：
Response.clearheaders
Response.AddHeader("Content-Type", "video/mp4")
Response.AddHeader("Content-Disposition", "inline;filename=""newvideo.mp4""")
dim Err as string = ""
Dim iStream As System.IO.Stream
' Buffer to read 10K bytes in chunk:
Dim buffer(buffersize) As Byte
' Length of the file:
Dim length As Integer
' Total bytes to read:
Dim dataToRead As Long
' Identify the file to download including its path.
Dim filepath As String = "./outout/videos/newvideo.mp4"
' Identify the file name.
Dim filename As String = System.IO.Path.GetFileName(filepath)
' Open the file.
try
iStream = New System.IO.FileStream(filepath, System.IO.FileMode.Open, IO.FileAccess.Read, IO.FileShare.Read)
catch ex as exception
throw new exception("Could not create FileStream for [" & filepath & "], error follows." & vbcrlf & ex.toString)
end try
Try
' Total bytes to read:
dataToRead = iStream.Length
' Read the bytes.
While dataToRead > 0
' Verify that the client is connected.
If system.web.httpcontext.current.Response.IsClientConnected Then
' Read the data in buffer
length = iStream.Read(buffer, 0, buffersize)
' Write the data to the current output stream.
system.web.httpcontext.current.Response.OutputStream.Write(buffer, 0, length)
' Flush the data to the HTML output.
system.web.httpcontext.current.Response.Flush()
ReDim buffer(buffersize) ' Clear the buffer
dataToRead = dataToRead - length
Else
'prevent infinite loop if user disconnects
dataToRead = -1
End If
End While
Catch ex As Exception
' Trap the error, if any.
err = "Error accessing " & filepath & " : " & ex.tostring
Finally
If IsNothing(iStream) = False Then
' Close the file.
iStream.Close()
End If
End Try
if err<>"" then throw new exception( err )
我在页面输出上的所有内容都是一个HTML视频播放器（chrome的基本播放器），它似乎超时并且PLAY按钮变为灰色。 Chrome开发者工具中的网络工具显示它正在下载45mb并获得200响应代码。这告诉我它工作正常。虽然我收到状态为“已取消”的第二个GET请求？
如果我访问www.mywebsite.com/output/videos/myvideo.mp4，那么这在浏览器中播放正常，因此我知道IIS配置为正确流式传输视频。
此外，如果我将响应内容处置更改为“附件”，则浏览器在转到我的ASPX页面时会正确强制下载视频，但这也无法在HTML播放器上正确播放。是否有一些“聪明”的HTML5 VIDEO标签正在阻止.aspx文件通过.net提供视频？或者我错过了回复标题？
谢谢！
答案 0 :(得分：3)
固定！
这里的问题可能与范围请求的HTML5视频实现有关。如果不在用于发送视频的页面中支持范围请求，它们将无法工作。
Scott Mitchell的这篇非常有用的帖子让我了解了这个案例： http://dotnetslackers.com/articles/aspnet/Range-Specific-Requests-in-ASP-NET.aspx
另一篇来自Chris Coulson的帖子，它提供了C＃中的解决方案实现！ http://blogs.visigo.com/chriscoulson/easy-handling-of-http-range-requests-in-asp-net/
我发现的代码Chris的vb.net端口如下所示，实现它只是将它放在你的页面中：
system.web.httpcontext.current.Response.ContentType = "video/" & convertFormat.toString
RangeDownload(convertedVideo, system.web.httpcontext.current)
VB.NET代码：
private sub RangeDownload( fullpath as string, context as HttpContext)
dim size as long
dim start as long
dim theend as long
dim length as long
dim fp as long =0
using reader as new StreamReader(fullpath)
size = reader.BaseStream.Length
start = 0
theend = size - 1
length = size
'/ Now that we've gotten so far without errors we send the accept range header
'* At the moment we only support single ranges.
'* Multiple ranges requires some more work to ensure it works correctly
'* and comply with the spesifications: http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
'*
'* Multirange support annouces itself with:
'* header('Accept-Ranges: bytes');
'*
'* Multirange content must be sent with multipart/byteranges mediatype,
'* (mediatype = mimetype)
'* as well as a boundry header to indicate the various chunks of data.
'*/
context.Response.AddHeader("Accept-Ranges", "0-" + size)
'// header('Accept-Ranges: bytes')
'// multipart/byteranges
'// http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
if (not String.IsNullOrEmpty(context.Request.ServerVariables("HTTP_RANGE"))) then
dim anotherStart as long = start
dim anotherEnd as long = theend
dim arr_split as string() = context.Request.ServerVariables("HTTP_RANGE").Split("=") 'new char[] { Convert.ToChar("=") })
dim range as string = arr_split(1)
'// Make sure the client hasn't sent us a multibyte range
if (range.IndexOf(",") > -1) then
'// (?) Shoud this be issued here, or should the first
'// range be used? Or should the header be ignored and
'// we output the whole content?
context.Response.AddHeader("Content-Range", "bytes " & start & "-" & theend & "/" & size)
throw new HttpException(416, "Requested Range Not Satisfiable")
end if
'// If the range starts with an '-' we start from the beginning
'// If not, we forward the file pointer
'// And make sure to get the end byte if spesified
if (range.StartsWith("-")) then
'// The n-number of the last bytes is requested
anotherStart = size - Convert.ToInt64(range.Substring(1))
else
arr_split = range.Split("-")
anotherStart = Convert.ToInt64(arr_split(0))
dim temp as long = 0
if (arr_split.Length > 1 andalso Int64.TryParse(arr_split(1).ToString(), temp)) then
anotherEnd = Convert.ToInt64(arr_split(1))
else
anotherEnd = size
end if
end if
'/* Check the range and make sure it's treated according to the specs.
' * http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
' */
'// End bytes can not be larger than $end.
if (anotherEnd > theend) then
anotherEnd = theend
else
anotherEnd = anotherEnd
end if
'// Validate the requested range and return an error if it's not correct.
if (anotherStart > anotherEnd or anotherStart > size - 1 or anotherEnd >= size) then
context.Response.AddHeader("Content-Range", "bytes " + start + "-" + theend + "/" + size)
throw new HttpException(416, "Requested Range Not Satisfiable")
end if
start = anotherStart
theend = anotherEnd
length = theend - start + 1 '// Calculate new content length
fp = reader.BaseStream.Seek(start, SeekOrigin.Begin)
context.Response.StatusCode = 206
end if
end using
'// Notify the client the byte range we'll be outputting
context.Response.AddHeader("Content-Range", "bytes " & start & "-" & theend & "/" & size)
context.Response.AddHeader("Content-Length", length.ToString())
'// Start buffered download
context.Response.WriteFile(fullpath, fp, length)
context.Response.End()
end sub