public static Thread showFilesInTreeView(this API_AmazonS3 amazonS3, TreeView treeView, string folderName) { treeView.backColor("LightPink"); // we need to run the next code in a separate thread or the treeView.backColor update doesn't show if (folderName.valid()) { return(O2Thread.mtaThread( () => { treeView.clear(); var files = amazonS3.files(folderName); foreach (var file in files) { var url = "{0}/{1}/{2}".format(amazonS3.defaultS3Server, folderName, file); treeView.add_Node(file, url.uri()); } treeView.backColor("White"); })); } return(null); }