using UnityEngine;

using System.Collections;  

public class Test : MonoBehaviour

{

    IEnumerator Start ()

    {

        yield return StartCoroutine(login());  

        Debug.Log("CCCCCCCCCCCCC");  

        Destroy(this.gameObject);

    }  

    IEnumerator login ()

    {

        Debug.Log("AAAAAAAAAAAAAAAAA");  

        yield return new WaitForSeconds(0);  

        Debug.Log("BBBBBBBBBBBBBBBBB");

    }

}

------print--------

AAAAAAAAAAA

BBBBBBBBBBB

CCCCCCCCCCC

using UnityEngine;

using System.Collections;  

public class Test : MonoBehaviour

{

    void Start ()

    {

        StartCoroutine(login());  

        Debug.Log("CCCCCCCCCCCCC");  

        Destroy(this.gameObject);

    }  

    IEnumerator login ()

    {

        Debug.Log("AAAAAAAAAAAAAAAAA");  

        yield return new WaitForSeconds(0);  

        Debug.Log("BBBBBBBBBBBBBBBBB");

    }

}

------print--------

AAAAAAAAAAA

CCCCCCCCCCC