public override bool Update()
{
if (operation != null)
{
return(false);
}
AssetBundleRes bundle = AssetsBundleManager.GetLoadedAssetBundle(assetBundleName, out downloadingError);
if (bundle != null)
{
if (isAdditive)
{
operation = SceneManager.LoadSceneAsync(sceneName);
}
else
{
operation = SceneManager.LoadSceneAsync(sceneName);
}
return(false);
}
else
{
return(true);
}
}
/// <summary>
/// 如果尚未下载，则设置给定资产包的下载操作。
/// </summary>
protected static bool LoadAssetBundleInternal(string _assetbundleName, bool _isLoadingManifest)
{
AssetBundleRes asset = null;
mLoadedAssetBundles.TryGetValue(_assetbundleName, out asset);
if (asset != null)
{
asset.mReferencedCount++;
return(true);
}
//我们是否需要考虑引用的WWW数量？
//在演示中，我们永远不会有重复的WWW，因为我们在调用另一个LoadAssetAsync（）/ LoadLevelAsync（）之前等待LoadAssetAsync（）/ LoadLevelAsync（）完成。
//但在实际情况中，用户可以多次调用LoadAssetAsync（）/ LoadLevelAsync（），然后等待它们完成，这可能有重复的WWW。
if (mDownloadingBundles.Contains(_assetbundleName))
{
return(true);
}
string assetBaseDownloadingURL = GetAssetBundleBaseDownloadingURL(_assetbundleName);
if (assetBaseDownloadingURL.ToLower().StartsWith("odr://"))
{
new ApplicationException("Can't load bundle " + _assetbundleName + " through ODR: this Unity version or build target doesn't support it.");
}
else if (assetBaseDownloadingURL.ToLower().StartsWith("res://"))
{
new ApplicationException("Can't load bundle " + _assetbundleName + " through asset catalog: this Unity version or build target doesn't support it.");
}
else
{
UnityWebRequest rq = null;
//WWW download = null;
if (!assetBaseDownloadingURL.EndsWith("/"))
{
assetBaseDownloadingURL += "/";
}
string url = assetBaseDownloadingURL + _assetbundleName;
//对于manifest assetbundle，总是下载它，因为我们没有哈希值。
rq = UnityWebRequest.Get(url);
//if (_isLoadingManifest)
//else
// rq = // WWW.LoadFromCacheOrDownload(url, mAssetBundleManifest.GetAssetBundleHash(_assetbundleName), 0);
// mProgressOperations.Add(new AssetBundleFromWeb(_assetbundleName,download));
}
mDownloadingBundles.Add(_assetbundleName);
return(false);
}
/// <summary>
/// 如果需要更多Update调用，则返回true。
/// </summary>
/// <returns></returns>
public override bool Update()
{
if (request != null)
{
return(false);
}
AssetBundleRes assetBundleRes = AssetsBundleManager.GetLoadedAssetBundle(assetBundleName, out downloadingError);
if (assetBundleRes != null)
{
///@TODO: 当资产包下载失败时，会抛出异常。
request = assetBundleRes.assetbundle.LoadAssetAsync(assetName, this.type);
return(false);
}
else
{
return(true);
}
}
/// <summary>
/// 下载完成后调用，实例化AssetBundleRes
/// </summary>
protected override void FinishDownload()
{
error = mWww.error;
if (!string.IsNullOrEmpty(error))
{
return;
}
AssetBundle _assetBundle = mWww.assetBundle;
if (_assetBundle == null)
{
error = string.Format("{0} 无效assetbundle资源", AssetbundleName);
}
else
{
assetBundleRes = new AssetBundleRes(mWww.assetBundle);
}
mWww.Dispose();
mWww = null;
}
/// <summary>
/// 检索先前通过LoadAssetBundle请求的资产包。
/// 如果尚未下载资产包或其中一个依赖项，则返回null。
/// </summary>
/// <param name="_assetbundleName"></param>
/// <param name="error"></param>
/// <returns></returns>
public static AssetBundleRes GetLoadedAssetBundle(string _assetbundleName, out string error)
{
if (mDownloadingErrors.TryGetValue(_assetbundleName, out error))
{
return(null);
}
AssetBundleRes loadedAB = null;
mLoadedAssetBundles.TryGetValue(_assetbundleName, out loadedAB);
if (loadedAB == null)
{
return(null);
}
string[] dependcies = null;
if (!mDependencies.TryGetValue(_assetbundleName, out dependcies))
{
return(loadedAB);
}
//确保加载所有依赖项
foreach (string dependcie in dependcies)
{
if (mDownloadingErrors.TryGetValue(dependcie, out error))
{
return(null);
}
//等待所有依赖的assetsBundle被加载。
AssetBundleRes dependentBundle;
mLoadedAssetBundles.TryGetValue(dependcie, out dependentBundle);
if (dependentBundle == null)
{
return(null);
}
}
return(loadedAB);
}