发送邮件使用的FileStream ASPNET大文件时，500MB OutOfMemoryException异常 [英] OutOfMemoryException when send big file 500MB using FileStream ASPNET
问题描述
我使用的文件流的读取大文件（> 500 MB）和我得到的OutOfMemoryException异常。
I'm using Filestream for read big file (> 500 MB) and I get the OutOfMemoryException.
我用Asp.net，.NET 3.5，WIN2003，IIS 6.0
I use Asp.net , .net 3.5, win2003, iis 6.0
我想这在我的应用程序：
I want this in my app:
从Oracle读取数据
Read DATA from Oracle
Uncom preSS文件中使用的FileStream和bzip2
Uncompress file using FileStream and BZip2
阅读文件uncom pressed并将其发送到asp.net页面下载。
Read file uncompressed and send it to asp.net page for download.
当我从磁盘读取文件，失败！并获得内存不足...
When I read file from disk, Fails !!! and get OutOfMemory...
。我的code是：
using (var fs3 = new FileStream(filePath2, FileMode.Open, FileAccess.Read))
{
byte[] b2 = ReadFully(fs3, 1024);
}
// http://www.yoda.arachsys.com/csharp/readbinary.html
public static byte[] ReadFully(Stream stream, int initialLength)
{
// If we've been passed an unhelpful initial length, just
// use 32K.
if (initialLength < 1)
{
initialLength = 32768;
}
byte[] buffer = new byte[initialLength];
int read = 0;
int chunk;
while ((chunk = stream.Read(buffer, read, buffer.Length - read)) > 0)
{
read += chunk;
// If we've reached the end of our buffer, check to see if there's
// any more information
if (read == buffer.Length)
{
int nextByte = stream.ReadByte();
// End of stream? If so, we're done
if (nextByte == -1)
{
return buffer;
}
// Nope. Resize the buffer, put in the byte we've just
// read, and continue
byte[] newBuffer = new byte[buffer.Length * 2];
Array.Copy(buffer, newBuffer, buffer.Length);
newBuffer[read] = (byte)nextByte;
buffer = newBuffer;
read++;
}
}
// Buffer is now too big. Shrink it.
byte[] ret = new byte[read];
Array.Copy(buffer, ret, read);
return ret;
}
现在，我指定我的问题更好。
Now, I specify my issue better.
Uncom preSS文件中使用的FileStream和bzip2是确定的，一切是正确的。
Uncompress file using FileStream and BZip2 is OK, all is right.
问题是以下内容：
阅读盘发大文件（> 500 MB）的字节[]和发送字节下载它响应（asp.net）。
Read fat big file in disk (> 500 MB) in byte[] and send bytes to Response (asp.net) for download it.
在使用
<一个href=\"http://www.yoda.arachsys.com/csharp/readbinary.html\">http://www.yoda.arachsys.com/csharp/readbinary.html
public static byte[] ReadFully
我得到的错误：OutOfMemoryException异常...
I get the error: OutOfMemoryException...
如果不是流（的FileStream，MemoryStream的，...）效果更佳BufferedStream
If better BufferedStream than Stream (FileStream, MemoryStream, ...) ??
使用BufferedStream，我可以读的700 MB大的文件？ （使用BufferedStream下载大文件的任何样本code源代码）
Using BufferedStream , Can I read big file of 700 MB ?? (any sample code source using BufferedStream for download big file)
我觉得，这是一个问题：不是如何阅读500MB的文件到内存？ ，但是，如何将大文件发送到ASPNET响应流？
I think, this is the question: Not "how to read a 500mb file into memory?" , But "how to send a large file to the ASPNET Response stream?"
我发现这个code。通过Cheeso：
I found this code by Cheeso:
using (var fs = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{
Response.BufferOutput= false; // to prevent buffering
byte[] buffer = new byte[1024];
int bytesRead = 0;
while ((bytesRead = fs.Read(buffer, 0, buffer.Length)) > 0)
{
Response.OutputStream.Write(buffer, 0, bytesRead);
}
}
这是好code 17高性能的任何改进？
Is it good code ?? any improvements for high performance ??
一个collegue说我，用
A collegue say me, use
Response.TransmitFile(filePath);
现在，另一个问题，更好的TransmitFile或code。通过Cheeso ??
Now, another question, better TransmitFile or code by Cheeso ??
许多年前，在MSDN杂志出现伟大的文章有关，但我不能访问<一个href=\"http://msdn.microsoft.com/msdnmag/issues/06/09/WebDownloads/\">http://msdn.microsoft.com/msdnmag/issues/06/09/WebDownloads/,
Many years ago, in msdn magazine appears great article about it but I cannot access http://msdn.microsoft.com/msdnmag/issues/06/09/WebDownloads/,
我觉得页面已被删除：（我很伤心吧（我很高兴，如果有人给我完整的文章+ code）
I think the page was deleted :'( I'm very sad about it (I'm happy if anyone send me the complete article + code)
任何建议，意见，样本code源??
Any suggestions, comments, sample code source??
推荐答案
我创建的下载页面，允许用户下载多达4GB的（可能更多）几个月前。这是我的工作片段：
I've created download page which allows user to download up to 4gb (may be more) few months ago. Here is my working snippet:
private void TransmitFile(string fullPath, string outFileName)
{
System.IO.Stream iStream = null;
// Buffer to read 10K bytes in chunk:
byte[] buffer = new Byte[10000];
// Length of the file:
int length;
// Total bytes to read:
long dataToRead;
// Identify the file to download including its path.
string filepath = fullPath;
// Identify the file name.
string filename = System.IO.Path.GetFileName(filepath);
try
{
// Open the file.
iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open,
System.IO.FileAccess.Read, System.IO.FileShare.Read);
// Total bytes to read:
dataToRead = iStream.Length;
Response.Clear();
Response.ContentType = "application/octet-stream";
Response.AddHeader("Content-Disposition", "attachment; filename=" + outFileName);
Response.AddHeader("Content-Length", iStream.Length.ToString());
// Read the bytes.
while (dataToRead > 0)
{
// Verify that the client is connected.
if (Response.IsClientConnected)
{
// Read the data in buffer.
length = iStream.Read(buffer, 0, 10000);
// Write the data to the current output stream.
Response.OutputStream.Write(buffer, 0, length);
// Flush the data to the output.
Response.Flush();
buffer = new Byte[10000];
dataToRead = dataToRead - length;
}
else
{
//prevent infinite loop if user disconnects
dataToRead = -1;
}
}
}
catch (Exception ex)
{
throw new ApplicationException(ex.Message);
}
finally
{
if (iStream != null)
{
//Close the file.
iStream.Close();
}
Response.Close();
}
}
这篇关于发送邮件使用的FileStream ASPNET大文件时，500MB OutOfMemoryException异常的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
