ScreenToGif.Modern.con_MoveDownwards_Click C# (CSharp) Method

        private void con_MoveDownwards_Click(object sender, EventArgs e)
        {
            StopPreview();

            //A frame need to be selected.
            if (tvFrames.SelectedNode == null) return;
            //If != 0 means that is the Main Node.
            if (tvFrames.SelectedNode.GetNodeCount(false) != 0) return;
            //This action can't be applied to the bottom frame.
            if (tvFrames.SelectedNode.Index == tvFrames.Nodes[0].Nodes.Count - 1) return;

            //Copy, RemoveAt, Insert;
            var aux = _listFramesEdit[trackBar.Value];
            var auxDelay = _listDelayEdit[trackBar.Value];
            var auxNode = tvFrames.Nodes[0].Nodes[trackBar.Value];

            _listFramesEdit.RemoveAt(trackBar.Value);
            _listDelayEdit.RemoveAt(trackBar.Value);
            tvFrames.Nodes[0].Nodes.RemoveAt(trackBar.Value);

            _listFramesEdit.Insert(trackBar.Value + 1, aux);
            _listDelayEdit.Insert(trackBar.Value + 1, auxDelay);
            tvFrames.Nodes[0].Nodes.Insert(trackBar.Value + 1, auxNode);

            tvFrames.SelectedNode = tvFrames.Nodes[0].Nodes[trackBar.Value + 1];
            SelectFrame(trackBar.Value + 1);

            DelayUpdate();
            GC.Collect();
        }