thewar_client/Client/Assets/1_Script/GridLayoutGroupSet.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class GridLayoutGroupSet : MonoBehaviour
{
    [ContextMenu("Test")]
    public void Test()
    {
        RectTransform rt = gameObject.GetComponent<RectTransform>();
        Debug.Log(rt.sizeDelta);
    }
}