unity二段跳不能实现，是哪里出了问题？

Question

using System.Collections;
using System.Collections.Generic;
using Unity.Jobs;
using UnityEngine;

public class Playercontrler : MonoBehaviour
{
public Rigidbody2D rbp;
public Collider2D cp;

public float speed;
public float jumpforce;
bool jump;
public float isjump;

public LayerMask G;
void Start()
{

}

void FixedUpdate()
{
    isjump = Input.GetAxis("Vertical");

    jpt();
    jpo();
}



void jpo()
{
    if(cp.IsTouchingLayers(G))
    {
        if (isjump==1)
        {
            rbp.velocity = new Vector2(rbp.velocity.x, jumpforce * Time.deltaTime);
            jump = false;

        }
        isjump = 0;
    }
}
void jpt()
{
    if(!cp.IsTouchingLayers(G))
    {
        if(isjump==1)
        {
            if (!jump)
            {
                rbp.velocity = new Vector2(rbp.velocity.x, jumpforce * Time.deltaTime);
            }
            jump = true;
        }
        isjump = 0;
    }
}

}

Answer 1

https://blog.csdn.net/tutuzuo/article/details/50757470