how to validate Access a file in C#

private bool CheckDirectoryWriteAccess(string dirPath)
{
    bool result = false;
    // check for directory access
    if (System.IO.Directory.Exists(dirPath))
    {
        try
        {
            // initalize temp filenam
            string filename = System.DateTime.Now.ToString("yyyymmdd_hhmmss_fff") + ".tmp";
            // try to create temp file
            System.IO.File.Create(dirPath + filename).Close();
            // check file exists and set return result
            if (System.IO.File.Exists(dirPath + filename))
            {
                result = true;
            }
            // delete temp file
            System.IO.File.Delete(dirPath + filename);                    
        }
        catch (UnauthorizedAccessException ex)
        {
            // code to handle UnauthorizedAccessException
        }
        catch (Exception ex)
        {
            // code to handle all other exceptions
        }

    }
    return result;
}