Unity 2D 为什么我的角色在地面不平坦时不会跳跃？

Question

My character is bouncing on a flat surface, as shown in the picture. but it doesn't jump when the floor is crooked.I don't know what I'm doing wrong. my character is jumping on flat ground. but my character doesn't jump when the ground isn't flat.

My Jump Script here:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityStandardAssets.CrossPlatformInput;

public class WalkJumpFire : MonoBehaviour {

    public CharacterController2D kontroller;
    Rigidbody2D rb;
    float dirX;

    [SerializeField]
    float moveSpeed = 5f, jumpForce = 800f, bulletSpeed = 500f;

    bool facingRight = true;
    Vector3 localScale;

    public Transform barrel;
    public Rigidbody2D bullet;

    // Use this for initialization
    void Start () {
        localScale = transform.localScale;
        rb = GetComponent<Rigidbody2D> ();
    }

    // Update is called once per frame
    void Update () {
        dirX = CrossPlatformInputManager.GetAxis ("Horizontal");

        if (CrossPlatformInputManager.GetButtonDown ("Jump"))
            Jump ();

        if (CrossPlatformInputManager.GetButtonDown ("Fire1"))
            Fire ();
    }

    void FixedUpdate()
    {
        rb.velocity = new Vector2 (dirX * moveSpeed, rb.velocity.y);

    }

    void LateUpdate()
    {
        CheckWhereToFace ();
    }

    void CheckWhereToFace()
    {
        if (dirX > 0)
            facingRight = true;
        else
            if (dirX < 0)
                facingRight = false;
        if (((facingRight) && (localScale.x < 0)) || ((!facingRight) && (localScale.x > 0)))
            localScale.x *= -1;
        transform.localScale = localScale;
    }

    void Jump()
    {
        if (rb.velocity.y == 0)
            rb.AddForce (Vector2.up * jumpForce);
    }

    void Fire()
    {
        var firedBullet = Instantiate (bullet, barrel.position, barrel.rotation);
        firedBullet.AddForce (barrel.up * bulletSpeed);
    }
}

Answer 1

As @derHugo mentioned, use the condition of your rigidbody lying on the ground (via isGrounded method) to instigate your jump:

public bool isGrounded;  

//During collisions you would still want your object to jump, such as jumping while touching the corner of a wall, so:
void OnCollisionStay()
{
        isGrounded = true;
}  

//Your not able to jump right after collision: (Also add layers so your object can't pass through walls or entities in the game)
void OnCollisionExit()
{
        isGrounded = false;
}

//Jump only if your object is on ground:
void Jump()
{
       if(isGrounded)
       {
          rb.AddForce (Vector2.up * jumpForce);
          //set it to false again so you can't multi jump:
          isGrounded = false;
       }
}