如何下载 AssetBundle 并将其保存在设备中

Question

我正在使用 LoadFromCacheOrDownload 函数，我只是不确定如何才能从 unity 内部下载资产包，然后将资产包加载到设备中的本地。谢谢！这是我目前使用的代码：

using UnityEngine.UI;
using System;


public class LoadScenes : MonoBehaviour
{
public string sceneAssetBundle;
public string sceneName;
public string sName;
public string bName;
public string BundleURL;
public int version;
public int downloaded = 0;


IEnumerator Start() {
    if (downloaded == 0){
        using (WWW www = WWW.LoadFromCacheOrDownload (BundleURL, version)) {
            yield return www;
            if (www.error != null)
                throw new Exception ("WWW download had an error:" + www.error);
            if (www.error == null) {
                AssetBundle bundle = www.assetBundle;
            }
        }
            if (Caching.ready == true) {
                downloaded = 1;
                yield return InitializeLevelAsync (sceneName, true);

            }
        }
    }


public void getScene(string sName){
    sceneName = sName;

}

public void getBundle(string bName){
    sceneAssetBundle = bName;

}


public IEnumerator InitializeLevelAsync (string levelName, bool isAdditive)
{
    // This is simply to get the elapsed time for this phase of AssetLoading.
    float startTime = Time.realtimeSinceStartup;

    // Load level from assetBundle.
    AssetBundleLoadOperation request = AssetBundleManager.LoadLevelAsync(sceneAssetBundle, levelName, isAdditive);
    if (request == null)
        yield break;
    yield return StartCoroutine(request);

    // Calculate and display the elapsed time.
    float elapsedTime = Time.realtimeSinceStartup - startTime;
    Debug.Log("Finished loading scene " + levelName + " in " + elapsedTime + " seconds" );
}
}

Answer 1

您应该使用 PlayerPrefs 了解资产何时下载，在尝试再次下载之前检查它是否已下载。这是一个例子

if (PlayerPrefs.GetInt("AssetLoaded", 0) == 0)
{
    //Save that we have down loaded Asset 
    PlayerPrefs.SetInt("AssetLoaded", 1);
    Debug.Log("Asset has NOT been downloaded. Downloading....");

    //DOWNLOAD ASSET HERE
    //.......
}
else
{
    Debug.Log("Asset already loaded. Can't download it again!");
}

将其与您问题中的代码合并：

IEnumerator Start() {
    if (PlayerPrefs.GetInt("AssetLoaded", 0) == 0){
        Debug.Log("Asset has NOT been downloaded. Downloading....");
        using (WWW www = WWW.LoadFromCacheOrDownload (BundleURL, version)) {
            yield return www;
            if (www.error != null)
                throw new Exception ("WWW download had an error:" + www.error);
            if (www.error == null) {
                AssetBundle bundle = www.assetBundle;
            }
        }
            if (Caching.ready == true) {
                downloaded = 1;
                //Save that we have down loaded Asset 
                PlayerPrefs.SetInt("AssetLoaded", 1);
                yield return InitializeLevelAsync (sceneName, true);

            }
        }else
          {
             Debug.Log("Asset already loaded. Can't download it again! Loading it instead");
             yield return InitializeLevelAsync (sceneName, true);
          }
    }

要重置它，只需调用 PlayerPrefs.DeleteKey("AssetLoaded");。

Answer 2

我认为您不想使用 LoadFromCacheOrDownload 函数，因为显然它会将您想要下载的任何内容保存在缓存内存中，这是您不想要的，因为该内存只能加载而不能通过代码。

对我来说最好的解决方案是使用 WebClient。

它是如何工作的？

您必须导入 C# System.Net 库（使用 System.Net;）
由于下载文件不是立竿见影的事情，你必须使用协程，它可以让你等到文件下载完成。

如何在代码中下载 AssetBundle 或任何文件

using System.Collections;
using UnityEngine;
using System;
using System.Net; //Most important Library

public class DownloadClass: MonoBehaviour
{
        //Your URL path
        string url = "https://yourUrl.com/fileName.extension";

        //Create a WebRequest instance
        Uri uri = new Uri(url);

        //Create a Client instance to download the WebRequest
        WebClient client = new WebClient();

        //Suscribe to the event ProgressChanged
        client.DownloadProgressChanged += Client_DownloadProgressChanged;

        //Create your coroutine to download your AssetBundle or any file (mp3, jpeg, etc)
        public IEnumerator DownLoadAsset()
        {
                //Start download and specify the save path
                client.DownloadFileAsync(uri, Application.persistentDataPath + "/yourPath/fileName");

                while(client.IsBusy)   // Wait until the file download is complete
                        yield return null;

                //Now your file is completely downloaded and saved
        }

        //Create your ProgressChanged "Listener"
        private void Client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
        {
                //Show download progress
                Debug.Log("Download Progress: " + e.ProgressPercentage);
        }

}

如何在代码中加载 AssetBundle 或任何文件

using System.Collections;
using UnityEngine;
using System;

public class LoadClass : MonoBehaviour
{
        //Variable to hold the asset bundle
        private AssetBundle bundle;

        public void LoadAsset()
        {
                //Check to load the bundle only once
                if (bundle != null)
                        bundle.Unload(true);

                //Load an AssetBundle in a specific path
                bundle = AssetBundle.LoadFromFile(Application.persistentDataPath + "/yourPath/fileName");

                //Your file is Now loaded, you can access to your data              
        }
}

如何在代码中删除 AssetBundle 或任何文件

using System.Collections;
using UnityEngine;
using System;
using System.IO;  //Most important Library

public class DeleteClass : MonoBehaviour
{
        public void DeleteAsset()
        {
                //If the file exits, Delete the file
                if (File.Exists(Application.persistentDataPath + "/yourPath/fileName"))
                        File.Delete(Application.persistentDataPath + "/yourPath/fileName");

                //Your file was delete from memory
        }
}

我希望这个解决方案对你有用。

如何下载 AssetBundle 并将其保存在设备中

How to Download an AssetBundle and then save it in the device

c#

assets

unity3d

assetbundle