Panel grid layout content size and and flicker

Hello,

I have this structure:

PanelContainer (with Mask and ScrollRect scripts)

---- PanelItems (with GridLayout script)

First problem: PanelItems have 20 buttons, set to be displayed in 2 rows, and I've set padding and spacing in GridLayout. Is there a way to have the cell size automatically expand to have the two rows fit in the PanelContainer? I managed to do that with a script to calculate the cellsize, is there a cleaner way?

Second problem: Buttons images are set at runtime, in Start() with this code: foreach (Transform child in panelItems.transform) { UnityEngine.UI.Image image = child.GetComponent(); image.sprite = (Sprite)Resources.Load("Icons/Thumbnails/" + listObjectsAR[i].name, typeof (Sprite)); } It works, but all the panel flickers for a second, how can I solve this? I tried to make the panel invisible, fill the buttons, and make it visible again, but if I deactivate it I lose access to the components, GetComponent returns null. Is there another way to make the panel invisible? Or reduce the flicker?

Thanks