UnityEngineComponent Velocity错误如何解决？

Question

我对团结很陌生，并且遇到了这个错误。
我真的不知道该怎么做才能解决它，所以我希望有人可以帮助我。

  

UnityEngine.Component'不包含对类型为'UnityEngine.Component'的velocity' and no extension method力度的定义。您是否缺少装配参考？'

using UnityEngine;

namespace UnitySampleAssets._2D

public class PlatformerCharacter2D : MonoBehaviour
{
    private bool facingRight = true; // For determining which way the player is currently facing.

    [SerializeField] private float maxSpeed = 10f; // The fastest the player can travel in the x axis.
    [SerializeField] private float jumpForce = 400f; // Amount of force added when the player jumps.    

    [Range(0, 1)] [SerializeField] private float crouchSpeed = .36f;
                                                 // Amount of maxSpeed applied to crouching movement. 1 = 100%

    [SerializeField] private bool airControl = false; // Whether or not a player can steer while jumping;
    [SerializeField] private LayerMask whatIsGround; // A mask determining what is ground to the character

    private Transform groundCheck; // A position marking where to check if the player is grounded.
    private float groundedRadius = .2f; // Radius of the overlap circle to determine if grounded
    private bool grounded = false; // Whether or not the player is grounded.
    private Transform ceilingCheck; // A position marking where to check for ceilings
    private float ceilingRadius = .01f; // Radius of the overlap circle to determine if the player can stand up
    private Animator anim; // Reference to the player's animator component.


    private void Awake()
    {
        // Setting up references.
        groundCheck = transform.Find("GroundCheck");
        ceilingCheck = transform.Find("CeilingCheck");
        anim = GetComponent<Animator>();
    }


    private void FixedUpdate()
    {
        // The player is grounded if a circlecast to the groundcheck position hits anything designated as ground
        grounded = Physics2D.OverlapCircle(groundCheck.position, groundedRadius, whatIsGround);
        anim.SetBool("Ground", grounded);

        // Set the vertical animation
        anim.SetFloat("vSpeed", rigidbody2D.velocity.y);
    }


    public void Move(float move, bool crouch, bool jump)
    {


        // If crouching, check to see if the character can stand up
        if (!crouch && anim.GetBool("Crouch"))
        {
            // If the character has a ceiling preventing them from standing up, keep them crouching
            if (Physics2D.OverlapCircle(ceilingCheck.position, ceilingRadius, whatIsGround))
                crouch = true;
        }

        // Set whether or not the character is crouching in the animator
        anim.SetBool("Crouch", crouch);

        //only control the player if grounded or airControl is turned on
        if (grounded || airControl)
        {
            // Reduce the speed if crouching by the crouchSpeed multiplier
            move = (crouch ? move*crouchSpeed : move);

            // The Speed animator parameter is set to the absolute value of the horizontal input.
            anim.SetFloat("Speed", Mathf.Abs(move));

            // Move the character
            rigidbody2D.velocity = new Vector2(move*maxSpeed, rigidbody2D.velocity.y);

            // If the input is moving the player right and the player is facing left...
            if (move > 0 && !facingRight)
                // ... flip the player.
                Flip();
                // Otherwise if the input is moving the player left and the player is facing right...
            else if (move < 0 && facingRight)
                // ... flip the player.
                Flip();
        }
        // If the player should jump...
        if (grounded && jump && anim.GetBool("Ground"))
        {
            // Add a vertical force to the player.
            grounded = false;
            anim.SetBool("Ground", false);
            rigidbody2D.AddForce(new Vector2(0f, jumpForce));
        }
    }


    private void Flip()
    {
        // Switch the way the player is labelled as facing.
        facingRight = !facingRight;

        // Multiply the player's x local scale by -1.
        Vector3 theScale = transform.localScale;
        theScale.x *= -1;
        transform.localScale = theScale;
    }
}

}