一个AssetBundle同时只能加载一次，所以实际使用中一般会伴随着AssetBundle包的管理。
下面是一个简单的AssetBundle管理器，提供了同步和异步加载函数：
using UnityEngine;
using System.Collections;
using System.Collections.Generic; public class AssetBundleManager
{
public static AssetBundleManager Instace
{
get
{
if (_instace == null) _instace = new AssetBundleManager();
return _instace;
}
}
private static AssetBundleManager _instace = null; private AssetBundleManifest manifest = null;
private Dictionary<string, AssetBundle> dicAssetBundle = new Dictionary<string, AssetBundle>(); // filename : Assets全路径，比如Assets/Prefab/***.prefab
public AssetBundle GetAssetBundle(string filePath)
{
AssetBundle ab = null;
dicAssetBundle.TryGetValue(AssetsNameToBundleName(filePath), out ab);
return ab;
} // 加载manifest，用来处理关联资源
public void LoadManifest()
{
AssetBundle bundle = AssetBundle.LoadFromFile(MainifestFilePath());
manifest = bundle.LoadAsset<AssetBundleManifest>("AssetBundleManifest");
// 压缩包直接释放掉
bundle.Unload(false);
bundle = null;
} // filename : Assets全路径，比如Assets/Prefab/***.prefab
public AssetBundle Load(string filename)
{
string bundleName = AssetsNameToBundleName(filename);
if (dicAssetBundle.ContainsKey(bundleName))
{
return dicAssetBundle[bundleName];
} string[] dependence = manifest.GetAllDependencies(bundleName);
for (int i = ; i < dependence.Length; ++i)
{
LoadInternal(dependence[i]);
} return LoadInternal(bundleName);
} // filename : Assets全路径，比如Assets/Prefab/***.prefab
public IEnumerator LoadAsync(string filename)
{
string bundleName = AssetsNameToBundleName(filename);
if (dicAssetBundle.ContainsKey(bundleName))
{
yield break;
} string[] dependence = manifest.GetAllDependencies(bundleName);
for (int i = ; i < dependence.Length; ++i)
{
yield return LoadInternalAsync(dependence[i]);
} yield return LoadInternalAsync(bundleName);
} public void Unload(string filename, bool force = false)
{
string bundleName = AssetsNameToBundleName(filename); AssetBundle ab = null;
if (dicAssetBundle.TryGetValue(bundleName, out ab) == false) return; if (ab == null) return; ab.Unload(force);
ab = null;
dicAssetBundle.Remove(bundleName);
} public void UnloadUnusedAssets()
{
Resources.UnloadUnusedAssets();
System.GC.Collect();
} public void Release()
{
foreach(var pair in dicAssetBundle)
{
var bundle = pair.Value;
if(bundle != null)
{
bundle.Unload(true);
bundle = null;
}
}
dicAssetBundle.Clear();
} private AssetBundle LoadInternal(string bundleName)
{
if (dicAssetBundle.ContainsKey(bundleName))
{
return dicAssetBundle[bundleName];
} AssetBundle bundle = AssetBundle.LoadFromFile(BundleNameToBundlePath(bundleName));
dicAssetBundle.Add(bundleName, bundle);
return bundle;
} private IEnumerator LoadInternalAsync(string bundleName)
{
if (dicAssetBundle.ContainsKey(bundleName))
{
yield break;
} AssetBundleCreateRequest req = AssetBundle.LoadFromFileAsync(BundleNameToBundlePath(bundleName));
yield return req; dicAssetBundle.Add(bundleName, req.assetBundle);
} // 名字依赖于存放目录
private string MainifestFilePath()
{
return Application.dataPath + "/StreamingAssets/StreamingAssets";
} // Assets/Prefab/***.prefab --> assets.prefab.***.prefab.assetbundle
private string AssetsNameToBundleName(string file)
{
string f = file.Replace('/', '.');
f = f.ToLower();
f += ".assetbundle";
return f;
} // assets.prefab.***.prefab.assetbundle --> C:/***path***/assets.prefab.***.prefab.assetbundle
private string BundleNameToBundlePath(string bundleFilename)
{
return System.IO.Path.Combine(Application.dataPath + "/StreamingAssets/", bundleFilename);
} }
当然bundle也可以通过WWW或其他的方式来加载，这一块Unity5到没有什么变化，具体使用方式可以参考我以前的博客。