修改一下加载逻辑

Assets/Scripts/TextureLoadHelp.cs

@@ -107,10 +107,10 @@ public class TextureLoadHelp : MonoBehaviour
         {
             Debug.Log($"{ab_Name} downloading...wait");
             yield return new WaitUntil(() => loadingABList[ab_Name] > 0);
-            if (loadingABList.ContainsKey(ab_Name))
-            {
-                loadingABList.Remove(ab_Name);
-            }
+            // if (loadingABList.ContainsKey(ab_Name))
+            // {
+            //     loadingABList.Remove(ab_Name);
+            // }
         }
         AssetBundle tempAb;
         Texture2D tex;
@@ -130,7 +130,7 @@ public class TextureLoadHelp : MonoBehaviour
         else
         {
             //添加到正在下载
-            loadingABList.Add(ab_Name,0);
+            loadingABList.TryAdd(ab_Name,0);
             WWW www = WWW.LoadFromCacheOrDownload($"{Application.streamingAssetsPath}/{ab_Name}",0);
             yield return www;
             if (www.isDone)