Deleting files in use 
<p>I created a simple program to delete temporary files in C# (for fun, not a major project) and am running into locked files (in use) issues.  How do you normally either exclude those files? For reference I am receiving the error:</p>

<p>The process cannot access the file 'ExchangePerflog_8484fa31c65c7a31cfcccd43.dat' because it is being used by another process.</p>

<p>Code:</p>

<pre><code>static void Main(string[] args)
    {
        string folderPath = string.Empty;
        folderPath = System.Environment.GetEnvironmentVariable("temp");
        deleteFilesInDirectory(folderPath);
    }

    public static void deleteFilesInDirectory(string folderPath) 
    {

        try
        {
            var dir = new DirectoryInfo(folderPath);
            dir.Attributes = dir.Attributes &amp; ~FileAttributes.ReadOnly;
            dir.Delete(true);
            MessageBox.Show(folderPath + " has been cleaned.");
        }
        catch (System.IO.IOException ex)
        {
            MessageBox.Show(ex.Message); 
            return;

        } 
    }     
</code></pre>
