This sample demonstrates visibility of the Tree Grid lines that separates the rows and columns. In this sample, you can change the gridline from the properties panel.
The gridLines property is used to control the line visibility that separates the rows and columns. Tree Grid allows us to display the following grid lines, Default - Shows the Horizontal line. None - Shows no line. Both - Shows both Horizontal and Vertical lines. Horizontal - Shows the Horizontal line. Vertical - Shows the Vertical line. In this demo, you can modify the visibility of gridlines by selecting values in the dropdown. More information on the grid lines can be found in documentation section