Unity 错误：UnityEngine.Component' 不包含“速度”的定义

Question

我对 C# 很陌生，如果这很明显，请原谅我。

我按照this tutorial 中的步骤进行操作，但在第六步遇到了问题。它给出的错误是这样的：它给出的错误是这样的：

UnityEngine.Component' does not contain a definition for `velocity' and no extension method `velocity' of type `UnityEngine.Component' could be found. Are you missing an assembly reference?'

代码如下：

using UnityEngine;
using System.Collections;

public class RobotController : MonoBehaviour {
//This will be our maximum speed as we will always be multiplying by 1
public float maxSpeed = 2f;
//a boolean value to represent whether we are facing left or not
bool facingLeft = true;
//a value to represent our Animator
Animator anim;
// Use this for initialization
void Start () {
  //set anim to our animator
  anim = GetComponent<Animator>();

}

// Update is called once per frame
void FixedUpdate () {

  float move = Input.GetAxis ("Horizontal");//Gives us of one if we are moving via the arrow keys
  //move our Players rigidbody
  rigidbody2D.velocity = new Vector3 (move * maxSpeed, rigidbody2D.velocity.y);
  //set our speed
  anim.SetFloat ("Speed",Mathf.Abs (move));
  //if we are moving left but not facing left flip, and vice versa
  if (move < 0 && !facingLeft) {

   Flip ();
  } else if (move > 0 && facingLeft) {
   Flip ();
  }
}

//flip if needed
void Flip(){
  facingLeft = !facingLeft;
  Vector3 theScale = transform.localScale;
  theScale.x *= -1;
  transform.localScale = theScale;
}
}

错误在第23行：

rigidbody2D.velocity = new Vector3 (move * maxSpeed, rigidbody2D.velocity.y);

Answer 1

rigidbody2D 曾经是一个继承自 MonoBehaviour 的 Component 的变量。现在已弃用。

现在，您必须声明它并使用 GetComponent<Rigidbody>(); 对其进行初始化，就像您为 Start() 函数中的 Animator(anim) 变量所做的那样。此外，为了不将自己与旧变量混淆，我建议您将 rigidbody2D 重命名为其他名称。在下面的示例代码中，我将它重命名为rigid2D 并声明它。

如果您不重命名它，您可能会收到一条警告：

严重性代码描述项目文件行抑制状态 警告 CS0108 'RobotController.rigidbody2D' 隐藏继承的成员 'Component.rigidbody2D'。如果要隐藏，请使用 new 关键字。

public class RobotController: MonoBehaviour
{
    public float maxSpeed = 2f;
    //a boolean value to represent whether we are facing left or not
    bool facingLeft = true;
    //a value to represent our Animator
    Animator anim;

    //Declare rigid2D
    Rigidbody rigid2D;
    // Use this for initialization
    void Start()
    {
        //set anim to our animator
        anim = GetComponent<Animator>();

        //Initialize rigid2D
        rigid2D = GetComponent<Rigidbody>();
    }

    // Update is called once per frame
    void FixedUpdate()
    {

        float move = Input.GetAxis("Horizontal");//Gives us of one if we are moving via the arrow keys
                                                 //move our Players rigidbody
        rigid2D.velocity = new Vector3(move * maxSpeed, rigid2D.velocity.y);
        //set our speed
        anim.SetFloat("Speed", Mathf.Abs(move));
        //if we are moving left but not facing left flip, and vice versa
        if (move < 0 && !facingLeft)
        {

            Flip();
        }
        else if (move > 0 && facingLeft)
        {
            Flip();
        }
    }

    //flip if needed
    void Flip()
    {
        facingLeft = !facingLeft;
        Vector3 theScale = transform.localScale;
        theScale.x *= -1;
        transform.localScale = theScale;
    }
}

Answer 2

你只需在开始函数中创建一个刚体对象，

Rigidbody rigidbody = GetComponent<Rigidbody>();

如果您使用的是 2D 动画，请使用以下代码，

Rigidbody2D rigidbody = GetComponent<Rigidbody2D>();