Can't write to file immediately after creation

Question

In the following code:

if (File.Exists(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/data.dat"))
{
    File.AppendAllText(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/data.dat", temp);
}
else
{
    File.Create(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/data.dat");
    File.SetAttributes(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/data.dat", FileAttributes.Hidden);
    File.AppendAllText(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/data.dat", temp);
}

for some reason, the first time this code is run, it creates the file just fine, but does not write to it, and it will not until i exit the app, and re-run it. the 2nd, 3rd, and so on runs work just fine, its just the initial that's screwy. any ideas? file names and directories are random since i was just testing something so you should be able to change those to whatever you want if you're testing something. Thanks in advance

What's the full exception text/exact problem? – Kieren Johnstone Jan 09 '12 at 08:04 — Kieren Johnstone, Jan 09 '12 at 08:04
Piotr Auguscik(below) answered it. there was no exception. – user1138208 Jan 09 '12 at 08:08 — user1138208, Jan 09 '12 at 08:08

Peter PAD · Answer 1 · 2012-01-09T10:48:54.197

You should put .Close() after File.Create

File.Create(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/data.dat").Close();

Read more at MSDN File.WriteAllText

score 6 · Answer 2 · answered Jan 09 '12 at 08:05

6

File.Create is returning you stream to file you might want to close it before you try to reopen it again.

answered Jan 09 '12 at 08:05

Piotr Auguscik

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score 4 · Answer 3 · answered Jan 09 '12 at 08:06

File.AppendAllText() will create the file if it does not already exist, so you could just do:

File.AppendAllText(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/data.dat", temp);         
File.SetAttributes(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData) + "/data.dat", FileAttributes.Hidden);

See if that helps :)

score 3 · Answer 4 · answered Jan 09 '12 at 08:06

3

Skip creating the file, the AppendAllText method creates it anyway if it's not there. I'm guessing the file.create might leave a file lock or file handle open.

answered Jan 09 '12 at 08:06

linkerro

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1

No need to guess. File.Create() does keep a handle open until the stream created is closed/disposed. – ThunderGr Apr 11 '14 at 04:01

Can't write to file immediately after creation

4 Answers4