每种实现的混合实体组件系统

Question

尝试测试Unity3d简单混合实体组件系统。 坚持执行ForEach

一共有三个脚本，第三个是问题

// ------------------------ //

 using UnityEngine;
 public class CupsuleParams : MonoBehaviour
 {
     public float speed = 3;
 }

// ----------------------- //

 using UnityEngine;
 public struct CupsuleComponent 
 {
     public Rigidbody rigidbody;
 }

// ----------------------- //

 using UnityEngine;
 using Unity.Entities;
 public class CupsuleSystem : ComponentSystem
 {
     protected override void OnUpdate()
     {
         // used to be correct before update of the ETC. And all the internet lessons do this way
         //foreach (CupsuleComponent component in GetEntities<CupsuleComponent>())
         //{
         //    component.rigidbody.AddForce(Vector3.up);
         //}

         // this shows error
         Entities.ForEach((Entity entities, CupsuleComponent component) =>
         {            
          component.rigidbody.AddForce(Vector3.up);         
         });
     }
 }