private void fileList_MouseDoubleClick(object sender, MouseEventArgs e) { if (fileList.SelectedItems.Count == 0 || fileList.SelectedItems[0] == null) { return; } if (fileList.SelectedItems[0].Tag is FileItem File) { IFileFormat Node = GetFileFormatFromExtension(File.Extension); if (Node != null) { if (Node is IModelContainerFormat ModelFormat) { Node.Open(File); ModelViewer.SetModel(ModelFormat.ToGenericModel()); } } } }