smart-bow-infrared/Assets/BowArrow/Scripts/Expand/SB_EventSystem/MouseConfirm/CircleRayCastChecker.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;

public class CircleRayCastChecker : MonoBehaviour, ICanvasRaycastFilter
{
    public float radius;

    public bool IsRaycastLocationValid(Vector2 sp, Camera eventCamera)
    {
        RectTransformUtility.ScreenPointToLocalPointInRectangle(transform as RectTransform, sp, eventCamera,
            out Vector2 localPos);
        float dis = Vector3.Distance(localPos, Vector3.zero);
        return dis <= radius;
    }
}