How do I make my code skip something if there is an error C# .NET

Question

This is really hard for me because I dont know the correct term used for this but essentially what I want to accomplish is.. If my code cant execute it jumps over and tried the next thing.. Not sure if I need to use a try & catch loop but here it goes.

As you can see I am trying to delete stuff from my temp folder with a press of a button and it throws me a error on my PC saying that

Access to the path "file name" is denied.

I would like the code to overlook that and jump to the next file and try that one or even better just give the code access to delete the file, not if the file is in use of course.

Is this possible?

private void label6_Click(object sender, EventArgs e)
{
    string tempPath = Path.GetTempPath();
    DirectoryInfo di = new DirectoryInfo(tempPath);

    foreach (FileInfo file in di.GetFiles())
    {
        file.Delete();
    }
}

Yes it is possible. And you're on the right path, I think. – Broots Waymb May 06 '16 at 15:13 — Broots Waymb, May 06 '16 at 15:13

score 6 · Answer 1 · answered May 06 '16 at 15:10

6

foreach (FileInfo file in di.GetFiles())
{
    try
    {
        file.Delete();
    }
    catch(Exception e)
    {
        // Log error.
    }
}

answered May 06 '16 at 15:10

mariocatch

8,305
8
50
71

4

`catch(Exception e)` - never put such code again (catching all errors), `catch(IOException e)` – Dmitry Bychenko May 06 '16 at 15:11
2

It's ok to use in some critical running cases. Blindly dismissing it is just as bad. – mariocatch May 06 '16 at 15:12
I wient with that code but I removed the e from catch (Exception e), you said that it will log the error, where exactly would it log the error? – Alexander. Matt May 06 '16 at 15:23
You can use the `e` variable to get the Exception information and do with it as you please. Such as logging it to the Console. – mariocatch May 06 '16 at 15:25

score 3 · Answer 2 · answered May 06 '16 at 15:18

Just catch required exceptions (and in your case ignore them):

private void label6_Click(object sender, EventArgs e)
{
    string tempPath = Path.GetTempPath();
    DirectoryInfo di = new DirectoryInfo(tempPath);

    foreach (FileInfo file in di.GetFiles())
    {
        try 
        { 
            file.Delete();
        }
        catch (IOException) 
        {
            // ignore all IOExceptions:
            //   file is used (e.g. opened by some other process)
        }
        catch (SecurityException) {
            // ignore all SecurityException: 
            //   no permission
        } 
        catch (UnauthorizedAccessException) 
        {
            // ignore all UnauthorizedAccessException: 
            //   path is directory
            //   path is read-only file 
        }
    }
}

score 1 · Answer 3 · answered May 06 '16 at 15:15

1

What you want is a very common programming feature called Exception Handling, or Error Handling. Using this feature allows you to tell the code what to do if an exception is thrown. In C# (and most languages), you use a try-catch block. At it's most basic, it looks like:

try
{
    file.Delete();
}
catch(Exception e)
{
    //log error or display to user
}

//execution continues

If file.Delete() throws an exception, the exception will be 'caught' in the catch block, and you can then examine the exception and take action accordingly, before continuing on.

Some resources:

Microsoft Documentation on Exception Handling
Eric Lippert's thoughts on Exception Handling (this is crucial for beginners in my opinion)

answered May 06 '16 at 15:15

Jonesopolis

25,034
12
68
112

how do I make it so if it hits an error it just moves on to the next item int he directory? – Alexander. Matt May 06 '16 at 15:42
@Alexander.Matt you would wrap the entire try/catch in some sort of loop – Jonesopolis May 06 '16 at 15:44
Any specific loop you would recommend? – Alexander. Matt May 06 '16 at 15:47

score 0 · Answer 4 · edited May 23 '17 at 10:28

0

You need to catch the exception and make a descision on whether to exit the loop

see this question - How handle an exception in a loop and keep iterating?

edited May 23 '17 at 10:28

Community

1
1

answered May 06 '16 at 15:07

Richard

1,804
16
22

score 0 · Answer 5 · answered May 06 '16 at 15:09

0

First you should add condition checking for what could raise an error. If there are other conditions that you can't control in your code then add a try-catch statement.

answered May 06 '16 at 15:09

wajiro_91

170
1
9

How do I make my code skip something if there is an error C# .NET

5 Answers5