1.Buttons
Grid layout Group,Set group of Buttons vertical by one column,
but The Size is hard to arrange.So
1>Create new GameObject in canvas with component of rect transform and Grid
layout Group.
2>Then Create several Buttons under the Gameobject
3>scale the gameobject smaller to available size
4>then turn off the component Grid layout Group,then
arrange the rect transform to adapt to the shape of Grid group of buttons,center to it's center.
5>move the gameobject to the available position
6>then put the component Grid layout Group of the
GameObject
to the target panel.
7>Arrange the anchors of each button to adapt to the target rect
transform.