异步loadasset和instatiate现在支持async await 语法

LoadRequest和InstatiateRequest支持yield return

Assets/VersionFlow/Runtime/LoadAssetRequest.cs

@@ -1,10 +1,11 @@
 using System;
 using System.Collections;
+using System.Threading.Tasks;
 using UnityEngine;
 
 namespace VersionFlow.Runtime
 {
-    public abstract class LoadAssetRequest
+    public abstract class LoadAssetRequest : CustomYieldInstruction
     {
         protected IEnumerator enumerator;
         protected Coroutine coroutine;
@@ -13,14 +14,12 @@ namespace VersionFlow.Runtime
         public bool Error => IsDone && asset == null;
 
         internal UnityEngine.Object asset;
-        public event Action OnComplete;
 #if UNITY_EDITOR
         public string StackInfoInEditor;
 #endif
         public LoadAssetRequest(IEnumerator enumerator)
         {
             this.enumerator = enumerator;
-
 #if UNITY_EDITOR
             StackInfoInEditor = string.Empty;
             var st = new System.Diagnostics.StackTrace(true);
@@ -35,11 +34,6 @@ namespace VersionFlow.Runtime
 #endif
         }
 
-        protected void RaiseOnComplete()
-        {
-            OnComplete?.Invoke();
-        }
-
         internal void Start()
         {
             if (IsDone) return;
@@ -58,9 +52,10 @@ namespace VersionFlow.Runtime
             }
 
             asset = null;
-            IsDone = false;
+            IsDone = true;
-        }
 
+            RaiseTaskComplete();
+        }
 
 
         internal virtual IEnumerator Task()
@@ -76,41 +71,53 @@ namespace VersionFlow.Runtime
             IsDone = true;
             coroutine = null;
 
-            OnComplete?.Invoke();
+            RaiseTaskComplete();
         }
+
+        protected abstract void RaiseTaskComplete();
     }
 
     public class LoadAssetRequest<T> : LoadAssetRequest where T : UnityEngine.Object
     {
-        public T Asset => asset as T;
+        TaskCompletionSource<T> loadTaskSrc;
+        public T Asset
+        {
+            get
+            {
+                if (!IsDone)
+                {
+                    throw new Exception("Asset Load not Finish");                    
+                }
+                var result = asset as T;
+                return result;
+            }
+        }
+
 
 
         public LoadAssetRequest(IEnumerator enumerator) : base(enumerator)
         {
-
+            loadTaskSrc = new TaskCompletionSource<T>();
-        }
         }
 
-    public class InstantiateRequest : LoadAssetRequest<GameObject>
+        public Task<T> GetAsset()
+        {
+            return loadTaskSrc.Task;
+        }
+
+        protected override void RaiseTaskComplete()
+        {
+            if (Error)
+                loadTaskSrc.TrySetCanceled();
+            else
+                loadTaskSrc.TrySetResult(asset as T);
+        }
+
+        public override bool keepWaiting => !IsDone;
+    }
+
+    public sealed class InstantiateRequest : LoadAssetRequest<GameObject>
     {
         public InstantiateRequest(IEnumerator enumerator) : base(enumerator) { }
-
-        internal override IEnumerator Task()
-        {
-            yield return null;//等待一帧
-
-            while (enumerator.MoveNext()) yield return enumerator.Current;
-#if UNITY_EDITOR
-            if (enumerator.Current == null)
-            {
-                VersionFlowX.Error(StackInfoInEditor);
-            }
-#endif
-            asset = enumerator.Current as UnityEngine.Object;
-            IsDone = true;
-            coroutine = null;
-
-            RaiseOnComplete();
-        }
     }
 }