TreeList columns have the same order as fields in data objects. You can use the columns array to specify a different order. To reorder a column at runtime, change its visibleIndex property.
Users can drag and drop column headers to reorder columns. To enable this feature, set the allowColumnReordering property to true. If you do not want users to drag a specific column, disable its allowReordering property. In this demo, users cannot drag the Full Name column.