Version: 2017.1
public float preferredWidth ;

Description

The preferred width this layout element should be allocated if there is sufficient space.

The preferredWidth can be set to -1 to remove the size.

using UnityEngine;
using System.Collections;
using UnityEngine.UI; // Required when using UI elements.

public class ExampleClass : MonoBehaviour { public Transform MyContentPanel;

//Sets the flexible height on on all children in the content panel. public void Start() { //Assign all the children of the content panel to an array. LayoutElement[] myLayoutElements = MyContentPanel.GetComponentsInChildren<LayoutElement>();

//For each child in the array change its LayoutElement's preferred width size to 250. foreach (LayoutElement element in myLayoutElements) { element.preferredWidth = 250f; } } }