Can't delete temp files because of errors

Question

I'm getting an unhandled exception of type System.IO.IOException occurring in mscorlib.dll because the file I'm trying to delete is being used by another process.

I want it to skip the used files.

private void button1_Click(object sender, EventArgs e)
{
    System.IO.DirectoryInfo directory = 
        new System.IO.DirectoryInfo(@"C:\Users\fatih\AppData\Local\Temp");

    foreach (System.IO.FileInfo file in directory.GetFiles()) file.Delete();
    foreach (System.IO.DirectoryInfo subDirectory in directory.GetDirectories()) 
        subDirectory.Delete(true);
}

You can't delete a file that is currently being used by another application. I think the error message is pretty clear. — Matias Cicero, Sep 08 '16 at 19:22
some other program has it open. close all programs and then try. ... you probably have it open in your dev environment. — Hogan, Sep 08 '16 at 19:22
Check that you don't also have it open in the preview pane of windows explorer. — RSSM, Sep 08 '16 at 19:27
Then just wrap it in a `try { // try and delete } catch { // do nothing }` block... Google (other search engines available) is your friend :) — Geoff James, Sep 08 '16 at 19:29
[Why are you deleting other application's files](http://meta.stackexchange.com/questions/66377)? They're not yours, you know. Is it OK for my app to delete all you files? — Dour High Arch, Sep 08 '16 at 20:33

score 7 · Answer 1 · edited Sep 27 '16 at 17:02

7

If it's not important that you delete everything, use:

private void button1_Click(object sender, EventArgs e)
{
    string directory = @"C:\Users\fatih\AppData\Local\Temp";
    deleteDirectory(directory);
}
private void deleteDirectory(string directory){
    foreach (string file in Directory.GetFiles(directory)) 
    {
        try{
             File.Delete(file);
        }
        catch(Exception e0){
        Console.WriteLine(e0.Message+"\n"+e0.Source);//not necessary but nice to learn from
        }
    }
    foreach (string direc in Directory.GetDirectories(directory)) {
          deleteDirectory(direc);
          Directory.Delete(direc,true);
    }
}

This will simply skip over any file or directory that has a problem and delete everything else.

edited Sep 27 '16 at 17:02

Raktim Biswas

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answered Sep 08 '16 at 19:30

Shannon Holsinger

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since i dont understand much of this what is the e1 and e0 it also gives me a error – Fatih Tkale Sep 08 '16 at 19:34
Severity Code Description Project File Line Warning CS0168 The variable 'e1' is declared but never used CSCleaner D:\Programming\Visual Studio\CSCleaner\CSCleaner\Form1.cs 40 – Fatih Tkale Sep 08 '16 at 19:36
Try it now with the above changes – Shannon Holsinger Sep 08 '16 at 19:37
@ShannonHolsinger You're missing brackets on your second foreach – CDspace Sep 08 '16 at 19:41
Much obliged, @CDspace - that's what I get for typing in the box and using OP's pasted text. Fatih - this should work for you now. If not, let me know what error – Shannon Holsinger Sep 08 '16 at 19:43
IT WORKED THANKKKS <3 – Fatih Tkale Sep 08 '16 at 19:46
@ShannonHolsinger I figured I'd let you edit it, in case you meant different nestings of the loops, I'm not sure if `Directory.GetFiles` is recursive or not. If not, you might have to adjust your loops to get all the files in subdirectories as well – CDspace Sep 08 '16 at 19:46
Nah I don't think he wanted recursion. I appreciate the head's up. – Shannon Holsinger Sep 08 '16 at 19:47
@FatihTkale In case it's needed, see recursive traversal here http://stackoverflow.com/a/929277/1007939 – CDspace Sep 08 '16 at 19:48
Doesn't true include all files and subs for Directory.Delete? @FatihTkale - do you have sub-sub directories you need to get rid of, or is it all just one layer deep – Shannon Holsinger Sep 08 '16 at 19:48
it deletes temp folders aswell – Fatih Tkale Sep 08 '16 at 19:50
Cool - glad to help! Sorry for all the edits, but in the end it worked out. – Shannon Holsinger Sep 08 '16 at 19:51
actually it dont hmmm – Fatih Tkale Sep 08 '16 at 19:52
Ok - so you're saying there are still folders left after you run this that you don't want anymore? – Shannon Holsinger Sep 08 '16 at 19:58
yeah there are temp folders – Fatih Tkale Sep 08 '16 at 19:59
Ok I added recursion. That should work. If not, we'll see what the error is. – Shannon Holsinger Sep 08 '16 at 20:06
Don't worry - we'll get you there. It's the end of my day and I'm a bit frazzled, but we'll get this figured out no worries. – Shannon Holsinger Sep 08 '16 at 20:16
@FatihTkale sigh, just try the last code snippet in my answer... if it doesn't work, i will say no more. – Kelso Sharp Sep 08 '16 at 20:27
@KelsoSharp - Directory.Delete didn't work - that's why we're here. Well, it didn't work on the subs. We didn't try it on the Temp folder because he doesn't want to delete that. If it didn't work on subs, it won't work on root. So we need to find out what's getting thrown. – Shannon Holsinger Sep 08 '16 at 20:35
@FatihTkale Is it the same error? With this answer, if a file in a sub-directory is being used, it won't delete that file or the sub-directory it's in, that might be all you're noticing – CDspace Sep 08 '16 at 20:43
Yeah next step is to take out the try/catch and let the exceptions fly (poor man's debugging) – Shannon Holsinger Sep 08 '16 at 20:56
ultimately he should not be trying to delete things outside his app domain, he should not be storing items in a directory that is not exclusive to his app. if he was to use a custom directory that he created and storied his files in, this would never have been an issue at all – Kelso Sharp Sep 08 '16 at 21:04
Agreed. I'm closing my eyes and hoping it's some kind of utility or something. Ya never know... – Shannon Holsinger Sep 08 '16 at 21:06
heey i got it to work the thing was it just was using the folders :/ – Fatih Tkale Sep 09 '16 at 12:19
You mean it leaves the folders and you want them gone? – Shannon Holsinger Sep 09 '16 at 13:20

Kelso Sharp · Answer 2 · 2016-09-08T20:13:44.233

-2

Use the static versions of the directory and file methods, you cannot use a foreach on file.delete the way you are doing it because you are trying to do a delete operation on the thing you are looping through.

foreach (var file in Directory.GetFiles(directory))
{
   File.Delete(file);
}

Update: I did not notice the subdirectory delete, that is your issue, if you want to just delete everything including the directory you are on, then you are working too hard.

Directory.Delete(Directory, true);

Will wipe out the directory and all the subdirectories and files in the directory passed in.

Since you are still having issues, and everyone seems to think I am wrong here, I will give you the code to past into your solution.

private void button1_Click(object sender, EventArgs e)
{
   string directory = @"C:\Users\fatih\AppData\Local\Temp")
   Directory.Delete(directory, true);  
}

IF there is an outside process hanging on to the file this will not work, otherwise it will do what you want it to do

edited Sep 08 '16 at 20:13

answered Sep 08 '16 at 19:29

Kelso Sharp

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If you have an issue with my answer be a man and comment why. Not just mark it down. – Kelso Sharp Sep 08 '16 at 19:38
Not you, I know :) – Kelso Sharp Sep 08 '16 at 19:50
Did you test my code? I bet you didn't The reason he was getting the error in the first place is because the is trying to delete a file in a foreach loop that is part of the foreach loop, AND that is the same problem with deleting the sub directories, you cannot remove an item from a collection while looping through the same collection, what do you think has a reference to the file??? My completely removes that issue. If you can prove otherwise show me. – Kelso Sharp Sep 08 '16 at 19:57
@MichalHainc Also you are wrong, using the Static version of the Directory and File object requires you to pass in the path to the directory and file respectively and therefor have no reference to the directory or file he is trying to delete, so no it will not give him the same error. – Kelso Sharp Sep 08 '16 at 20:05
1

@Kelso [Directory.GetFiles](https://msdn.microsoft.com/en-us/library/07wt70x2(v=vs.110).aspx) returns a string array, which _is not_ modified real-time as files are deleted, so your argument is invalid – CDspace Sep 08 '16 at 20:15
@CDspace yes but notice the capital D on Directory that is the static version of the method, and you are correct, in the asker's question, he is looping through a list of FileInfo object and trying to delete them which you cannot do in a foreach that references the fileinfo collection you are looping on. it throws because you HAVE a reference to the file because its the file you are trying to delete – Kelso Sharp Sep 08 '16 at 20:21
1

@Kelso and your solution would prevent an `InvalidOperation` which occurs when trying to modify a managed list or the like. Whereas `Directory.GetFiles` still returns an array. I just tried OPs code on a folder without any files opened, and it worked. From the OP _i want it to skip the used files_, which only needs a try-except, like is said in the comments and Shannon's answer. – CDspace Sep 08 '16 at 20:38
@CDspace but he doesn't want to skip them, he wants to wipe out everything from that directory and down – Kelso Sharp Sep 08 '16 at 20:48
@MichalHainc I never said that it didn't work but its a lot more work than is needed for something simple, did you try my code? He is doing something in 30 lines of code that I was able to do in 2 lines, and his solution at this point leaves temp files still there if there are any references from the foreach loop. – Kelso Sharp Sep 08 '16 at 20:50
@Kelso In the post, and a comment, OP explicitly said he want's to skip them, and secondly, if the files are open in another process (the issue at hand, reading the OP again), your method still fails – CDspace Sep 08 '16 at 20:50
Hmm... there is an issue with trying to use DirectoryInfo and FileInfo to delete files in a foreach loop, throws a file in use error, even if the file is not in use by another application, in normal circumstances, you should never try and delete files from a directory that other applications use without explicitly identifying the file, and I made that assumption here. Since he is deleting files from a public folder, it very well could be another app holding the reference and I think that over all has been the confusion – Kelso Sharp Sep 08 '16 at 20:59

Can't delete temp files because of errors

2 Answers2