Unity 2D，GameObject居中

using UnityEngine;

public class CenterOnScreen : MonoBehaviour
{
    void Start()
    {
        CenterOnScreenHelper();
    }

    void CenterOnScreenHelper()
    {
        Vector3 screenPosition = Camera.main.WorldToScreenPoint(transform.position);
        screenPosition.x = (Screen.width - spriteRenderer.bounds.size.x) / 2;
        screenPosition.y = (Screen.height - spriteRenderer.bounds.size.y) / 2;
        transform.position = Camera.main.ScreenToWorldPoint(screenPosition);
    }
}

using UnityEngine;

public class CenterOnParent : MonoBehaviour
{
    void Start()
    {
        CenterOnParentHelper();
    }

    void CenterOnParentHelper()
    {
        if (transform.parent != null)
        {
            Vector3 parentSize = transform.parent.GetComponent<RectTransform>().sizeDelta;
            Vector3 localPosition = new Vector3(parentSize.x / 2, parentSize.y / 2, 0);
            transform.localPosition = localPosition;
        }
    }
}