How to open a file from Memory Stream

问题

Is it possible to open a file directly from a MemoryStream opposed to writing to disk and doing Process.Start() ? Specifically a pdf file? If not, I guess I need to write the MemoryStream to disk (which is kind of annoying). Could someone then point me to a resource about how to write a MemoryStream to Disk?

回答1:

It depends on the client :) if the client will accept input from stdin you could push the dta to the client. Another possibility might be to write a named-pipes server or a socket-server - not trivial, but it may work.

However, the simplest option is to just grab a temp file and write to that (and delete afterwards).

var file = Path.GetTempFileName();
using(var fileStream = File.OpenWrite(file))
{
    var buffer = memStream.GetBuffer();
    fileStream.Write(buffer, 0, (int)memStream.Length);
}

Remember to clean up the file when you are done.

回答2:

Path.GetTempFileName() returns file name with '.tmp' extension, therefore you cant't use Process.Start() that needs windows file association via extension.

回答3:

If by opening a file, you mean something like starting Adobe Reader for PDF files, then yes, you have to write it to a file. That is, unless the application provides you with some API do that.

One way to write a stream to file would be:

using (var memoryStream = /* create the memory stream */)
using (var fileStream = File.OpenWrite(fileName))
{
    memoryStream.WriteTo(fileStream);
}

来源：https://stackoverflow.com/questions/6236602/how-to-open-a-file-from-memory-stream

标签

file

file-io

memorystream