c# Cannot access file because it is being used by another process

Question

I am Trying To Write To A File After Creating It. And It Cannot access it, this is my code:

                string[] name = file.Split('.');
                HttpWebRequest FileRequest = (HttpWebRequest)WebRequest.Create(URL + name[0] + ".html");
                FileRequest.UserAgent = "FSL File Getter Agent";

                using (HttpWebResponse response = (HttpWebResponse)FileRequest.GetResponse())
                using (Stream stream = response.GetResponseStream())
                using (StreamReader reader = new StreamReader(stream))
                {
                    File.Create("C:\\Users\\" + System.Security.Principal.WindowsIdentity.GetCurrent().Name.Split('\\')[1] + "\\FSL\\" + Item + "\\" + file);
                    File.WriteAllText("C:\\Users\\" + System.Security.Principal.WindowsIdentity.GetCurrent().Name.Split('\\')[1] + "\\FSL\\" + Item + "\\" + file, reader.ReadToEnd());
                }

This Is The Stack Trace:

The process cannot access the file 'C:\Users\Winksplorer\FSL\TestPRG\main.py' because it is being used by another process.
Stack Trace:
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.StreamWriter.CreateFile(String path, Boolean append, Boolean checkHost)
   at System.IO.StreamWriter..ctor(String path, Boolean append, Encoding encoding, Int32 bufferSize, Boolean checkHost)
   at System.IO.File.InternalWriteAllText(String path, String contents, Encoding encoding, Boolean checkHost)
   at System.IO.File.WriteAllText(String path, String contents)
   at FSL.Program.GetPKG(String URL, String Item) in Z:\FSL\Program.cs:line 85
   at FSL.Program.Main(String[] args) in Z:\FSL\Program.cs:line 30

Pro tip: check what methods return before you use them.

ProgrammingLlama
– ProgrammingLlama

2021-11-12 01:30:50 +00:00
Commented Nov 12, 2021 at 1:30 — ProgrammingLlama
– ProgrammingLlama, Commented Nov 12, 2021 at 1:30

halfer · Accepted Answer · 2021-11-12 19:33:51Z

2

File.Create returns a FileStream for which you are happily ignoring. The result of this action is holding a handle to the file open which will not get disposed in a timely manner. Furthermore, you are then trying to use another method File.WriteAllText to write to that file using a different file handle which results in the error you see.

The solve to this is to use the FileStream you originally created, however even better, just use one of the streams CopyTo Methods

using var stream = response.GetResponseStream();
using var fs = File.Create(...)
stream.CopyTo(fs);

_{Disclaimer : There are async versions to these methods and many other ways to achieve the same thing. This wasn't tested, and was not meant to be the bastion of perfect code. It's only a tribute... in short, research the methods you use.}

edited Nov 12, 2021 at 19:33

halfer

20.2k20 gold badges110 silver badges207 bronze badges

answered Nov 12, 2021 at 1:19

TheGeneral

82k9 gold badges111 silver badges151 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

c# Cannot access file because it is being used by another process

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related