Unity/GameObject

子供のオブジェクト取得

GameObject child = obj.transform.Find("Child1Image").gameObject;

子供のオブジェクト一覧取得

Transform transforms  = obj.GetComponentInChildren<Transform>();
if (transforms.childCount == 0) {
    return;
}
foreach (Transform transform in transforms)
{
    GameObject body = transform.gameObject;
    Debug.Log("body.name=" + body.name);
}

配下のオブジェクトすべて取得

public void AllUnderObject(GameObject obj)
{
    Transform transforms = obj.GetComponentInChildren<Transform>();
    if (transforms.childCount > 0)
    {
        foreach (Transform transform in transforms)
        {
            AllUnderObject(transform.gameObject); // 再帰処理
        }
    }
}

参考：http://sonnahiga.blog.fc2.com/blog-entry-18.html

非アクティブへ

obj.SetActive(true);

オブジェクトより手前に

Transform trans1 = GameObject.Find("Object1").transform;
trans1.SetSiblingIndex(0);

ボタンなどが貼り付けられてるクラスからGameObject取得

GameObject btnObj = GameObject.Find("Button");
Button btn = btnObj.GetComponent<Button>();
GameObject obj = btn.gameObject;

こちらも参照

Unity/Csharp/オブジェクト操作 [ｼｮｰﾄｶｯﾄ]