初步整理并且学习unity3d资源加载方法，预计用时两天完成入门学习Unity3d常用两种加载资源方案：Resources.Load和AssetBundle
Resources.Load就是从一个缺省打进程序包里的AssetBundle里加载资源而一般AssetBundle文件需要你自己创建，运行时动态加载，
可以指定路径和来源的。其实场景里所有静态的对象也有这么一个加载过程，只是Unity后台替你自动完成
一：Resources.Load：使用这种方式加载资源，首先需要下Asset目录下创建一个名为Resources的文件夹，这个命名是U3D规定的方式，然后把资源文件放进去，
当然也可以在Resources中再创建子文件夹，当然在代码加载时需要添加相应的资源路径，下面是一个简demo，两个预设，Cube和Sphere，
其中Cube放在Resource中的Prebs中，而Sphere放在Resources跟目录下，下面分别实现Resources.Load资源的加载
using UnityEngine;
using System.Collections; public class LoadResDemo : MonoBehaviour { private string cubePath = "Prebs/MyCubePreb";
private string spherePath = "MySpherePreb";
void Start () {
//把资源加载到内存中
Object cubePreb = Resources.Load(cubePath, typeof(GameObject));
//用加载得到的资源对象，实例化游戏对象，实现游戏物体的动态加载
GameObject cube = Instantiate(cubePreb) as GameObject; //以下同理实现Sphere的动态实例化
//把资源加载到内存中
Object spherePreb = Resources.Load(spherePath, typeof(GameObject));
//用加载得到的资源对象，实例化游戏对象，实现游戏物体的动态加载
GameObject sphere = Instantiate(spherePreb) as GameObject;
} void Update () { }
}
将上面的脚本附加到某个游戏对象上，在运行游戏时就可以看到场景中动态创建的上面的游戏对象了
上面是第一种使用Resources.Load()的方式动态加载游戏对象的，然而在项目中更长用的却是第二种使用AssetBundle的方式动态加载游戏对象。
使用AssetBundle打包预设或者场景可以将与其相关的所有资源打包，这样很好地解决资源的依赖问题，使得我们可以方便的加载GameObject
首先需要打包资源：
using UnityEngine;
using System.Collections;
using UnityEditor;
using System.IO;
public class AesstBundleTest : MonoBehaviour { [MenuItem("Custom Bundle/Create Bundel Main")]
public static void creatBundleMain()
{
//获取选择的对象的路径
Object[] os = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);
bool isExist = Directory.Exists(Application.dataPath + "/StreamingAssets");
if (!isExist)
{
Directory.CreateDirectory(Application.dataPath + "/StreamingAssets");
}
foreach (Object o in os)
{
string sourcePath = AssetDatabase.GetAssetPath(o); string targetPath = Application.dataPath + "/StreamingAssets/" + o.name + ".assetbundle";
if (BuildPipeline.BuildAssetBundle(o, null, targetPath, BuildAssetBundleOptions.CollectDependencies))
{
print("create bundle cuccess!");
}
else
{
print("failure happen");
}
AssetDatabase.Refresh();
}
}
[MenuItem("Custom Bundle/Create Bundle All")]
public static void CreateBundleAll()
{
bool isExist = Directory.Exists(Application.dataPath + "/StreamingAssets");
if (!isExist)
{
Directory.CreateDirectory(Application.dataPath + "/StreamingAssets");
}
Object[] os = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);
if (os == null || os.Length == )
{
return;
}
string targetPath = Application.dataPath + "/StreamingAssets/" + "All.assetbundle";
if (BuildPipeline.BuildAssetBundle(null, os, targetPath, BuildAssetBundleOptions.CollectDependencies))
{
print("create bundle all cuccess");
}
else
{
print("failure happen");
}
AssetDatabase.Refresh();
} }
把上面的代码放在Editor中，在菜单栏中就可以看见自定的菜单项，选中需要打包的预设，就可以把对应的预设打包并输出到StreamAssets中了
然后是动态加载资源：
using UnityEngine;
using System.Collections; public class LoadBundleTest : MonoBehaviour {
//不同平台下StreamingAssets的路径是不同的，这里需要注意一下。
public static readonly string PathURL =
#if UNITY_ANDROID
"jar:file://" + Application.dataPath + "!/assets/";
#elif UNITY_IPHONE
Application.dataPath + "/Raw/";
#elif UNITY_STANDALONE_WIN || UNITY_EDITOR
"file://" + Application.dataPath + "/StreamingAssets/";
#else
string.Empty;
#endif // Update is called once per frame
void Update () { } void OnGUI()
{
if (GUILayout.Button("Load Bundle Main"))
{
string path_shpere = PathURL + "MySpherePreb.assetbundle";
StartCoroutine(loadBundleMain(path_shpere)); string path_cube = PathURL + "MyCubePreb.assetbundle";
StartCoroutine(loadBundleMain(path_cube));
print(path_cube);
} if (GUILayout.Button("Load Bundle All"))
{
StartCoroutine(loadBundleAll(PathURL + "All.assetbundle"));
}
} private IEnumerator loadBundleMain(string path)
{
WWW bundle = new WWW(path);
// yield return bundle;
Instantiate(bundle.assetBundle.mainAsset);
bundle.assetBundle.Unload(false);
yield return ;
} private IEnumerator loadBundleAll(string path)
{
WWW bundle = new WWW(path);
yield return bundle;
Instantiate(bundle.assetBundle.Load("MyCubePreb"));
Instantiate(bundle.assetBundle.Load("MySpherePreb"));
yield return ;
}
}