playableasset retuned a null playably on instantiate

现象：

playableasset retuned a null playably on instantiate

使用AB包的形式加载场景，携带有TimeLine的功能无法播放

工程分析：

场景A：

只有下载AB包和加载场景功能

场景B:

具体功能场景，有TimeLine组件

原因分析：

由于Unity有代码裁剪功能，

当打包时，你的C#脚本或Unity的功能未使用

则打包时这些Dll库或脚本将不会被携带到APP中

扫描二维码关注公众号，回复： 16902543 查看本文章

解决方案：

使用link.xml

这是link.xml的介绍

托管代码剥离 - Unity 手册

新建一个link.xml文件，放入到Assets任意目录下。

这个类名不好用。。。

		<type fullname="UnityEngine.Playables.PlayableAsset" preserve="all"/>
		<type fullname="UnityEngine.Playables.PlayableBehaviour" preserve="all"/>
		<type fullname="UnityEngine.Playables.PlayableDirector" preserve="all"/>

将以下内容填入，剩余的根据自己工程删减或增加

	<assembly fullname="UnityEngine.Timeline">
		<namespace fullname="UnityEngine.Timeline" preserve="all"/>
	</assembly>

<linker>
	<assembly fullname="UnityEngine.UI" preserve="all"/>
	
	<assembly fullname="UnityEngine.CoreModule" preserve="all">
		<type fullname="UnityEngine.SpriteRenderer" preserve="all"/>
		<type fullname="UnityEngine.Playables.PlayableAsset" preserve="all"/>
		<type fullname="UnityEngine.Playables.PlayableBehaviour" preserve="all"/>
		<type fullname="UnityEngine.Playables.PlayableDirector" preserve="all"/>
	</assembly>
	
	<assembly fullname="UnityEngine.Timeline">
		<namespace fullname="UnityEngine.Timeline" preserve="all"/>
	</assembly>
	
	<assembly fullname="UnityEngine.PhysicsModule" preserve="all"/>
	<assembly fullname="UnityEngine.DirectorModule" preserve="all"/>
	<assembly fullname="UnityEngine.AnimationModule" preserve="all"/>
	<assembly fullname="UnityEngine.AudioModule" preserve="all"/>
	<assembly fullname="UnityEngine.TerrainPhysicsModule" preserve="all"/>
	<assembly fullname="UnityEngine.WindModule" preserve="all"/>

	<assembly fullname="UnityEngine.DirectorModule" preserve="all"/>
	
	<assembly fullname="UnityEngine.Video" preserve="all"/>
	
	<assembly fullname="UnityEngine.VideoModule" preserve="all">
		<type fullname="UnityEngine.Video.VideoPlayer" preserve="all"/>
		<type fullname="UnityEngine.Video.VideoClip" preserve="all"/>
	</assembly>
 
	<assembly fullname="Vuforia.UnityExtensions" preserve="all"/>
	<assembly fullname="VuforiaScripts" preserve="all"/>
	
	<assembly fullname="Unity.RenderPipelines.Universal.Runtime" preserve="all"/>
	
	<assembly fullname="Assembly-CSharp" preserve="all"/>
</linker>