CrystalMpq.Explorer.MainForm.treeView_AfterSelect C# (CSharp) Method

        private void treeView_AfterSelect(object sender, TreeViewEventArgs e)
        {
            MpqFile file = e.Node.Tag as MpqFile;

            if (file == null)
            {
                directoryViewer.RootNode = e.Node;

                SetViewer(directoryViewer);

                //saveAsToolStripMenuItem.Enabled = false;
                //saveAsToolStripButton.Enabled = false;

                fileNameToolStripStatusLabel.Text = "";
            }
            else
            {
                string ext = Path.GetExtension(file.Name).ToLowerInvariant();
                FileViewer fileViewer;

                //saveAsToolStripMenuItem.Enabled = true;
                //saveAsToolStripButton.Enabled = true;
                if (fileViewerAssociations.TryGetValue(ext, out fileViewer))
                {
                    try
                    {
                        SetViewer(fileViewer);
                        fileViewer.File = file;
                    }
                    catch (Exception ex) { ErrorDialog(ex.ToString()); }
                }
                else
                    SetViewer(null);
                fileNameToolStripStatusLabel.Text = file.Name;
            }
            propertiesToolStripMenuItem1.Enabled = true;
            propertiesToolStripButton.Enabled = true;
        }