R – quick way to generate a <%@Register…%> line for a user control

Updated NOTE on this solution: Checking with FileAccess.ReadWrite will fail for Read-Only files so the solution has been modified to check with FileAccess.Read.

ORIGINAL: I've used this code for the past several years, and I haven't had any issues with it.

Understand your hesitation about using exceptions, but you can't avoid them all of the time:

protected virtual bool IsFileLocked(FileInfo file)
{
    try
    {
        using(FileStream stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None))
        {
            stream.Close();
        }
    }
    catch (IOException)
    {
        //the file is unavailable because it is:
        //still being written to
        //or being processed by another thread
        //or does not exist (has already been processed)
        return true;
    }

    //file is not locked
    return false;
}

Your only possible solutions are to:

• Move the control out of the directory its currently sharing with outer.ascx, or
• Re-register the control inside of the outer.ascx like you already mentioned
• Re-write them in code as controls in a separate library

I personally think moving is the easiest, if it will work for your solutions. Second would be re-registering, even though annoying. Abstracting them out into a full code library is probably not worth the effort if this is the only reason you are doing it.