使用 WebClient 在 Unity3d 中下载大文件

Question

我正在寻找有关使用 WebClient 在 Unity3d 中下载大型 (100mg+) 文件的任何想法。 WWW 异步运行，除了它返回内存错误并使应用程序崩溃之外，它是完美的，所以我已经转向此处概述的解决方案：

how to download a file from url and save in location using unity3d in C sharp?

这就像一个梦除了它会关闭我的应用程序中的所有脚本，直到下载完成。在下载进行的同时，我似乎什至无法运行加载栏。我已经尝试通过添加一个协程来处理下载来处理这个问题，但到目前为止，没有运气。

任何帮助将不胜感激。我的代码目前（经过多次迭代）看起来像：

C#

 void Update()
    {
    //Sets up the timer so I can use it to watch the debugging
        timer += Time.deltaTime;
        Debug.Log (timer);

//Checks to see if the file was already downloaded and saved.  If not, it begins downloading.
    if (FileExists == 0 && timer >= 5) {
        StartCoroutine ("DOWNLOAD");

    } 
//If the file already exists, it jumps straight to the next scene.
    else if (FileExists == 1) {
        Application.LoadLevelAsync ("Different_Level");
    }

    //These are the buttons.  One should stop the download if the player decides they don't want to wait.
    if (Input.GetMouseButtonUp (0)) {

        RaycastHit rc_hit;
        Ray hud_ray = Camera.main.ScreenPointToRay (Input.mousePosition);

    if (Physics.Raycast (hud_ray, out rc_hit, Mathf.Infinity, 1 << LayerMask.NameToLayer ("HUD"))) {

    if (rc_hit.transform.gameObject == b_BackButton) {

        StopCoroutine ("EN_Loop");
        Application.LoadLevelAsync ("Other_Level"); 
                            }
                    }
            }

}

//This is what should happen when the video is done downloading
void AllDone ()

{
    Debug.Log ("Download Complete");
    Application.LoadLevelAsync ("Next_Level");
}

////This is the coroutine I created int he hopes that I could get the download to run in the background.
IEnumerator DOWNLOAD()
{
    Debug.Log("downloading_EN");
    WebClient client = new WebClient();
    client.DownloadFile ("http://ServerInfo.net/moviefile.mp4", Application.persistentDataPath + "/" + "moviefile.mp4");
    yield return null;

    AllDone ();

}

Answer 1

尝试使用 WebClient.DownloadFileAsync 不锁定主线程（因此您的其他脚本仍将运行）并使用 WebClient.DownloadFileCompleted 事件来了解它何时完成。

使用 WebClient 无需使用协程，请确保只调用该方法一次：

void DownloadFile()
{
    WebClient client = new WebClient();
    client.DownloadFileCompleted += new System.ComponentModel.AsyncCompletedEventHandler( DownloadFileCompleted );
    client.DownloadFileAsync ((new Uri ("http://ServerInfo.net/moviefile.mp4", Application.persistentDataPath + "/" + "moviefile.mp4"));
}

void DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
{
    if (e.Error == null)
    {
        AllDone ();
    }
}

有关 DownloadFileAsync 的更多信息：

https://msdn.microsoft.com/en-us/library/system.net.webclient.downloadfileasync%28v=vs.110%29.aspx

还有 DownloadFileCompleted 事件：

https://msdn.microsoft.com/en-us/library/system.net.webclient.downloadfilecompleted%28v=vs.110%29.aspx