使 IEnumerator 以某种方式返回值的解决方法

Question

在我的Unity游戏中，您可以在地形表面上放置各种对象，并且当放置新对象时，我需要将时间戳保存在文件中。我有保存系统工作，在一些帮助下，我能够从服务器获取时间戳。似乎您必须使用 IEnumerator 才能从服务器获取数据，但这给我带来了一个新问题。由于IEnumerator不是一个函数，它不能简单地返回任何东西。而且由于它无法返回任何内容，因此我需要一种解决方法，将时间戳从IEnumerator传递回请求的位置。我计划如何获得时间戳：

 int _timestamp = ServerTime.Get();

所以我可以轻松地像

gameObject.GetComponent<_DrillStats>().timestamp = _timestamp;
gameObject.GetComponent<_OtherStats>().timestamp = _timestamp;
gameObject.GetComponent<_EvenMoreStats>().timestamp = _timestamp;

以下是接收时间戳的完整代码：

using UnityEngine;
using System;
using System.Collections;
public class ServerTime : MonoBehaviour
{
    private static ServerTime localInstance;
    public static ServerTime time { get { return localInstance; } }
    private void Awake()
    {
        if (localInstance != null && localInstance != this)
        {
            Destroy(this.gameObject);
        }
        else
        {
            localInstance = this;
        }
    }
    public static void Get()
    {
        if (time == null)
        {
            Debug.Log("Script not attached to anything");
            GameObject obj = new GameObject("TimeHolder");
            localInstance = obj.AddComponent<ServerTime>();
            Debug.Log("Automatically Attached Script to a GameObject");
        }
        time.StartCoroutine(time.ServerRequest());
    }
    IEnumerator ServerRequest()
    {
        WWW www = new WWW("http://www.businesssecret.com/something/servertime.php");
        yield return www;
        if (www.error == null) 
        {
            int _timestamp = int.Parse (www.text);
            // somehow return _timestamp
            Debug.Log (_timestamp);
        }
        else
        {
            Debug.LogError ("Oops, something went wrong while trying to receive data from the server, exiting with the following ERROR: " + www.error);
        }
    }
}

Answer 1

这就是我在评论部分的意思：

public static void Get(Action<int> callback)
{
    if (time == null)
    {
        Debug.Log("Script not attached to anything");
        GameObject obj = new GameObject("TimeHolder");
        localInstance = obj.AddComponent<ServerTime>();
        Debug.Log("Automatically Attached Script to a GameObject");
    }
    time.StartCoroutine(time.ServerRequest(callback));
}
IEnumerator ServerRequest(Action<int> callback)
{
    WWW www = new WWW("http://www.businesssecret.com/something/servertime.php");
    yield return www;
    if (www.error == null)
    {
        int _timestamp = int.Parse(www.text);
        // somehow return _timestamp
        callback(_timestamp);
        Debug.Log(_timestamp);
    }
    else
    {
        Debug.LogError("Oops, something went wrong while trying to receive data from the server, exiting with the following ERROR: " + www.error);
    }
}

我使两个函数都Action<int>作为参数。

美国证券总局：

将ServerTime.Get();替换为：

ServerTime.Get((myTimeStamp) =>
{
    Debug.Log("Time Stamp is: " + myTimeStamp);
    gameObject.GetComponent<_DrillStats>().timestamp = myTimeStamp;
    gameObject.GetComponent<_OtherStats>().timestamp = myTimeStamp;
    gameObject.GetComponent<_EvenMoreStats>().timestamp = myTimeStamp;
});

Answer 2

您可以将时间戳保存到字段中，并在协程完成后访问它。

您可以使用带有布尔标志的 while 循环来等待协程完成。