Should Dispose() or Finalize() be used to delete temporary files?

Question

I have a class that makes use of temporary files (Path.GetTempFileName()) while it is active. I want to make sure these files do not remain on the user\'s hard driv

Answer 1

A nice way is suggested by David M. Kean on the MSDN entry on Path.GetTempFileName. He creates a wrapper class implementing IDisposable that will automatically remove the file:

public class TemporaryFile : IDisposable
{
    private bool _isDisposed;

    public bool Keep { get; set; }
    public string Path { get; private set; }

    public TemporaryFile() : this(false)
    {
    }

    public TemporaryFile(bool shortLived)
    {
        this.Path = CreateTemporaryFile(shortLived);
    }

    ~TemporaryFile()
    {
        Dispose(false);
    }

    public void Dispose()
    {
        Dispose(false);
        GC.SuppressFinalize(this);
    } 

    protected virtual void Dispose(bool disposing)
    {
        if (!_isDisposed)
        {
            _isDisposed = true;

            if (!this.Keep)
            {
                TryDelete();   
            }
        }
    }

    private void TryDelete()
    {
        try
        {
            File.Delete(this.Path);
        }
        catch (IOException)
        {
        }
        catch (UnauthorizedAccessException)
        {
        }
    }

    public static string CreateTemporaryFile(bool shortLived)
    {
        string temporaryFile = System.IO.Path.GetTempFileName();

        if (shortLived)
        { 
            // Set the temporary attribute, meaning the file will live 
            // in memory and will not be written to disk 
            //
            File.SetAttributes(temporaryFile, 
                File.GetAttributes(temporaryFile) | FileAttributes.Temporary);
        }

        return temporaryFile;
    }
}

Using the new class is easy, just type the following:

using (TemporaryFile temporaryFile = new TemporaryFile())
{
    // Use temporary file
}

If you decide, after constructing a TemporaryFile, that you want to prevent it from being deleted, simply set the TemporaryFile.Keep property to true:

using (TemporaryFile temporaryFile = new TemporaryFile()) 
{ 
    temporaryFile.Keep = true; 
}