How to get the width + height of a RectTransform controlled by a Grid Layout Group?

Question

There is a RectTransform being controlled by a Grid Layout Group or some other Layout Group, because of this, the sizeDelta, anchorMin/Max, offsetMin/Max, rect, members all return 0, 0 but in the Inspector it does indeed show the width and height for the transform, but it is inaccessable.

I want to be able to get the w + h without knowing if the RectTransform is being controlled by a layout group.

Can anyone help? Thanks!

Answer 1

Answer by EParent · May 16, 2015 at 01:30 AM

I have the same problem

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Answer 2

Answer by mikest · Aug 04, 2016 at 12:41 PM

i see this is old and i was searching for a better answer myself. The problem is that the Unity UI doesn't know the size until all the elements are drawn (which with a grid makes no sense but whatever) so you can use a coroutine with a 1 frame delay to wait for the draw and then get the values from the rect.

 using UnityEngine;
 using System.Collections;
 
 public class GridElementWidth : MonoBehaviour {
     
     private float width;
     private RectTransform rt;
 
     void Start () {
 
         rt = GetComponent<RectTransform>();
         setWidth();
 
     }
 
     private void setWidth () {
         
         StartCoroutine(delayWidth());
 
     }
 
     private IEnumerator delayWidth () {
 
         yield return 0;
 
         width = rt.rect.width;
 
     }
 
 }

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wedgiebee · Oct 13, 2016 at 01:21 AM 3

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Ins$$anonymous$$d of a one frame delay, have you tried using Canvas.ForceUpdateCanvases()? So in start you could try

 void Start()
 {
     Canvas.ForceUpdateCanvase();
     rt = GetComponent<RectTransform>();
     width = rt.rect.width;
 }

yale3d wedgiebee · Jul 03 at 02:19 PM 0

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Actually, this is the correct solution. Thank you - eternal life and free beer for you, my friend!

mikest · Oct 23, 2016 at 02:14 PM 0

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Yep, that worked :) to allow for getting the width but (as always) a new problem immediately emerged. Clearing the grid children and adding more results in the transform.childCount returning the destroyed children and the newly added children if they both happen in the same frame. So trying to dynamically resize a grid still doesn't work right unless the grid had no children in that frame. [EDIT] calling transform.DetachChildren() after destroying resolves this issue with the childCount

Answer 3

Answer by caicai1355 · Jun 28, 2019 at 07:50 PM

 transform.parent.GetComponent<GridLayoutGroup>().cellSize

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How to get the width + height of a RectTransform controlled by a Grid Layout Group?

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