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为了熟悉一下资源加载的API,做了一个加载图片的小demo,实现了4种加载图片方式,并且把同步与异步做了区分。
使用unity开发游戏的过程中,资源的加载一直都是需要重点关注的。unity一共提供了5种资源加载的方式,分别是Resources(只能加载Resources目录中的资源),AssetBundle(只能加载AB资源,当前设备允许访问的路径都可以),WWW(可以加载任意处资源,包括项目外资源(如远程服务器)),AssetDatabase(只能加载Assets目录下的资源,但只能用于Editor),UnityWebRequest(可以加载任意处资源,是WWW的升级版本)。关于加载的的具体方法建议直接看Unity的API,讲解的比较明白,这里提一下同步与异步加载的意思与优缺点:
同步:并不是按字面意思的同时或一起,而是指协同步调,协助、相互配合。是按先后顺序执行在发出一个功能调用时,在没有得到返回结果之前一直在等待,不会继续往下执行。异步:刚好和同步相反,也就是在发出一个功能调用时,不管没有没得到结果,都继续往下执行,异步加载至少有一帧的延迟。
同步的优点:管理方便,资源准备好可以及时返回。缺点:没有异步快。
异步的优点:速度快与主线程无关。缺点:调用比较麻烦,最好的做法是使用回调。
在UnityWebRequest和WWW的使用过程中使用了回调,为了方便以后自己使用,贴一下代码:
- public interface IResourcesLoadingMode {
- void ResourcesLoading<T>(T t,string path, bool IsAsync) where T:UnityEngine.Object;
- void ResourcesUnLoading<T>(T t)where T:UnityEngine.Object;
-
- }
然后是资源加载的基类:
- public class ResourcesLoadingMode : IResourcesLoadingMode
- {
- public Image Img;
- public MonoBehaviour MB;
-
- public virtual void ResourcesLoading<T>(T t,string path, bool IsAsync) where T:UnityEngine.Object
- {
- throw new NotImplementedException();
- }
-
- public virtual void ResourcesUnLoading<T>(T t) where T : UnityEngine.Object
- {
- throw new NotImplementedException();
- }
- }
这里的monoBehaviour是因为整个资源加载器没有继承MonoBehaviour,在异步加载的时候可以把上层控制层的MonoBehavior拿过来,以便可以调用协程实现异步加载。这是一种解决方案,在老大的教导下采用了第二种使用回调函数的方案。
Resouces方式:
- public override void ResourcesLoading<T>(T t,string path, bool IsAsync)
- {
-
- if (IsAsync == false)
- {
- T load = Resources.Load<T>(path);
- t = load;
- Debug.Log("===="+path+"====");
- if (t.GetType() == Img.sprite.GetType())
- {
- Img.sprite = t as Sprite;
- Resources.UnloadAsset(t);
- }
- }
- else
- {
- T load = Resources.LoadAsync<T>(path).asset as T;
- t = load;
- if (t.GetType() == Img.sprite.GetType())
- {
- Img.sprite = t as Sprite;
- Resources.UnloadAsset(t);
- }
- }
- }
AssetDatabase方式:
- public override void ResourcesLoading<T>(T t,string path, bool IsAsync)
- {
- if (IsAsync==false)
- {
- //s=string.Format( "Assets/Image/{0}.jpg",Index.ToString())
- T load = AssetDatabase.LoadAssetAtPath<T>(path);
- Debug.Log(path);
- t = load;
- Debug.Log(t.name);
- if (t.GetType() == Img.sprite.GetType())
- {
- Img.sprite = t as Sprite;
- Resources.UnloadAsset(t);
- }
- else
- {
- Debug.Log(t.name);
- }
- }
-
- else
- {
- Debug.Log("assetdatabase没有异步加载");
- }
- }
WWW方式:
- public override void ResourcesLoading<T>(T t,string path,bool isAsync)
- {
- if (isAsync == true)
- {
- // MB.StartCoroutine(WWWLoad());
- }
- else
- {
- Debug.Log("----WWW没有同步加载----");
- }
- }
-
- public override void ResourcesUnLoading<T>(T t)
- {
- base.ResourcesUnLoading<T>(t);
-
- }
-
- public static IEnumerator WWWLoad(string url, Action<WWW>callback)
- {
- Debug.Log("----WWW协程调用----");
- //string url = string.Format(@"file://{0}/{1}.jpg", Application.streamingAssetsPath, Index.ToString());
- WWW www = new WWW(url);
- yield return www;
- callback.Invoke(www);
- yield return null;
- }
WWW方式的回调(上层的逻辑来决定需要加载什么资源,写在回调函数里):
-
- /// <summary>
- /// WWW回调函数
- /// </summary>
- /// <param name="obj"></param>
- private void WWWcallback(object obj)
- {
- WWW www = obj as WWW;
- Texture2D tex = www.texture;
- BG.sprite = Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), Vector2.zero);
- Debug.Log("----callback调用----");
- www.Dispose();
- }
UnityWebRequest方式:
- public override void ResourcesLoading<T>(T t,string path,bool isAsync)
- {
-
- if (isAsync==false)
- {
- Debug.Log("unityWebRequest没有同步加载");
- }
- }
-
- public override void ResourcesUnLoading<T>(T t)
- {
- base.ResourcesUnLoading<T>(t);
- }
-
- public static IEnumerator UnityWebRequestLoad(string url,Action<UnityWebRequest>callback)
- {
- //string url =string.Format( @"file://{0}/{1}.jpg", Application.streamingAssetsPath,Index.ToString());
- UnityWebRequest webRequest = UnityWebRequestTexture.GetTexture(url);
- yield return webRequest.SendWebRequest();
- if (webRequest.isNetworkError || webRequest.isHttpError)
- {
- Debug.Log(webRequest.error);
- }
- else
- {
- callback.Invoke(webRequest);
- yield return null;
- //Texture2D tex = DownloadHandlerTexture.GetContent(webRequest);
- //Img.sprite = Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), Vector2.zero);
- }
- }
- }
UnityWebRequest的回调:
- /// <summary>
- /// UnityWebRequest回调函数
- /// </summary>
- /// <param name="obj"></param>
- private void unityWebRequestcallback(object obj)
- {
- UnityWebRequest request = obj as UnityWebRequest;
- Texture2D tex = DownloadHandlerTexture.GetContent(request);
- BG.sprite = Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), Vector2.zero);
- request.Dispose();
- }
最后的业务层代码也贴一点核心的方法:
-
- using System.Collections;
- using System.Collections.Generic;
- using UnityEngine;
- using UnityEngine.Networking;
- using UnityEngine.UI;
-
- public class ModeControl : MonoBehaviour {
-
-
- public bool IsAsync; //是否异步加载
- public Image BG;
- public ResourcesModeEnum ModeEnum; //资源加载类型
- private bool Next;
-
- ResourcesLoadingMode mode = null;
- Mode_Resources resourcesMode = null;
- Mode_AssetDatabase assetDatabaseMode = null;
- Mode_WWW wwwMode = null;
- Mode_UnityWebRequest unityWebRequestMode = null;
-
-
- private int textureIndex=1; // 图片路径索引
-
-
- void Awake()
- {
- resourcesMode = new Mode_Resources();
- assetDatabaseMode = new Mode_AssetDatabase();
- wwwMode = new Mode_WWW();
- unityWebRequestMode = new Mode_UnityWebRequest();
- }
-
-
- private IEnumerator PreviousPageBtnClick(ResourcesModeEnum modeEnum)
- {
- changeColor = true;
- yield return new WaitForSeconds(1);
- Next = false;
- ResourceModeChoice(modeEnum);
- colorChange = true;
- Debug.Log("----上一页按钮点击----");
- }
- private IEnumerator NextPageBtnClick(ResourcesModeEnum modeEnum)
- {
- changeColor = true;
- yield return new WaitForSeconds(1);
- Next = true;
- ResourceModeChoice(modeEnum);
- colorChange = true;
- Debug.Log("----下一页按钮点击----");
-
- }
-
- /// <summary>
- /// 资源加载方式公共方法
- /// </summary>
- /// <param name="modeEnum">资源类型</param>
- private void ResourceModeChoice(ResourcesModeEnum modeEnum)
- {
- switch (modeEnum)
- {
- case ResourcesModeEnum.ResourcesMode:
- mode = resourcesMode;
- ChangePage();
- mode.ResourcesLoading(BG.sprite,textureIndex.ToString(), IsAsync);
- break;
- case ResourcesModeEnum.WWWMode:
- mode = wwwMode;
- ChangePage();
- StartCoroutine(Mode_WWW.WWWLoad(string.Format(@"file://{0}/{1}.jpg", Application.streamingAssetsPath, textureIndex.ToString()), WWWcallback));
- break;
- case ResourcesModeEnum.AssetDatabaseMode:
- mode = assetDatabaseMode;
- ChangePage();
- mode.ResourcesLoading(BG.sprite, string.Format("Assets/Image/{0}.jpg", textureIndex.ToString()), IsAsync);
- break;
- case ResourcesModeEnum.UnityWebMode:
- mode = unityWebRequestMode;
- ChangePage();
- StartCoroutine(Mode_UnityWebRequest.UnityWebRequestLoad(string.Format(@"file://{0}/{1}.jpg", Application.streamingAssetsPath, textureIndex), unityWebRequestcallback));
- break;
- case ResourcesModeEnum.NULL:
- mode.ResourcesUnLoading(BG.sprite);
- BG.sprite = null;
- break;
- default:
- break;
- }
- }
-
- /// <summary>
- /// 换页公共方法
- /// </summary>
- private void ChangePage()
- {
-
- if (Next == false) textureIndex--;
- if (Next == true) textureIndex++;
- mode.Img = BG;
- mode.MB = this.GetComponent<MonoBehaviour>();
- // mode.ResourcesLoading<Sprite>(BG.sprite, IsAsync);
-
- // mode.ResourcesUnLoading(BG.sprite);
- }
- private void ResourcesClick()
- {
- ModeEnum = ResourcesModeEnum.ResourcesMode;
- ResourceModeChoice(ModeEnum);
- SetTipText(TipText,"ResourcesMode");
- }
- private void AssetBundleBtnClick()
- {
- //TODO
- }
- private void WWWBtnClick()
- {
- if (IsAsync == false)
- {
- ModeEnum = ResourcesModeEnum.NULL;
- SetTipText(TipText, "WWW没有同步加载");
- }
- else
- {
- ModeEnum = ResourcesModeEnum.WWWMode;
- ResourceModeChoice(ModeEnum);
- SetTipText(TipText, "WWWMode");
- }
-
- }
- private void AssetDatabaseBtnClick()
- {
- if (IsAsync == false)
- {
- ModeEnum = ResourcesModeEnum.AssetDatabaseMode;
- ResourceModeChoice(ModeEnum);
- SetTipText(TipText, "AssetDatabaseMode");
- }
- else
- {
- ModeEnum = ResourcesModeEnum.NULL;
- SetTipText(TipText, "AssetDatabase没有异步加载");
- }
-
- }
- private void UnityWebRequestBtnClick()
- {
- if (IsAsync == false)
- {
- ModeEnum = ResourcesModeEnum.NULL;
- SetTipText(TipText, "UnityWebRequest没有同步加载");
- }
- else
- {
- ModeEnum = ResourcesModeEnum.UnityWebMode;
- ResourceModeChoice(ModeEnum);
- SetTipText(TipText, "UnityWebRequestMode");
- }
-
- }
- private void SynBtnClick()
- {
- IsAsync = false;
- SetTipText(IsAnsynText, "当前为同步加载方式");
- }
- private void AsynBtnClick()
- {
- IsAsync = true;
- SetTipText(IsAnsynText, "当前为异步加载方式");
- }
-
- /// <summary>
- /// WWW回调函数
- /// </summary>
- /// <param name="obj"></param>
- private void WWWcallback(object obj)
- {
- WWW www = obj as WWW;
- Texture2D tex = www.texture;
- BG.sprite = Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), Vector2.zero);
- Debug.Log("----callback调用----");
- www.Dispose();
- }
-
- /// <summary>
- /// UnityWebRequest回调函数
- /// </summary>
- /// <param name="obj"></param>
- private void unityWebRequestcallback(object obj)
- {
- UnityWebRequest request = obj as UnityWebRequest;
- Texture2D tex = DownloadHandlerTexture.GetContent(request);
- BG.sprite = Sprite.Create(tex, new Rect(0, 0, tex.width, tex.height), Vector2.zero);
- request.Dispose();
- }
-
- private void SetTipText(Text text,string str)
- {
- text.text = str;
- }
- }
这次的demo让我认识自己很多的不足,接口,类的继承,同步与异步,资源的卸载,还有很关键的一点,写的很多代码不能复用,在资源加载器写了具体的实现,这些东西应该放在上层业务层去决定你要什么资源就加载什么资源,把加载的类型和路径传进去就行了。下次千万注意,单一职责原则,可以很大的降低代码的耦合。 这只是个练习加载图片的小Demo,后面可以考虑拓展成一个通用的资源加载类。完整Demo放在了Github上,地址 https://github.com/hezhangqiang1/ResourceLoadingMode 如果这篇博客对你有点帮助,请帮忙点个Star,谢谢!
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