我的“如果”陈述无法按预期工作

Question

In my Unity C# game for Android, I want to detected when the closest gameobject to the character is the one im looking for (left), and, if the player of the game has not swiped left on the screen (swipeLeft), I want to change a value in my code called strike . But It is not working properly.

When Im in the game view the leftSwipe value does not work every time (It does when the if function is removed) and strike does not change at all. I would like to know how to fix this or is there is an alternative to this problem.

Here is the if statement:

if ((closestPlatform = left) && (leftSwipe = false)) { strike = 1; }

Here is the entire C# script:

using UnityEngine;
using System.Collections;

public class SwipeChecker : MonoBehaviour
{

    public float maxTime;
    public float minSwipeDistance;

    float startTime;
    float endTime;

    Vector3 startPos;
    Vector3 endPos;

    float swipeDistance;
    float swipeTime;
    public float swipeScore;

    public GameObject left;
    public GameObject right;
    public GameObject up;
    public GameObject down;
    public GameObject swipeChecker;
    public GameObject[] platforms = new GameObject[5];

    public bool leftSwipe;
    public bool didntSwipe;

    public float strike;



    public GameObject closestPlatform;





    // Use this for initialization

    public GameObject FindClosestPlatform()
    {
        GameObject[] gos;
        GameObject[] gos2;
        GameObject[] gos3;
        GameObject[] gos4;
        gos = GameObject.FindGameObjectsWithTag("platform");

        GameObject closest = null;
        float distance = Mathf.Infinity;
        Vector3 position = transform.position;
        foreach (GameObject go in gos)

        {
            Vector3 diff = go.transform.position - position;
            float curDistance = diff.sqrMagnitude;
            if (curDistance < distance)
            {
                closest = go;
                distance = curDistance;
            }
        }
        return closest;
    }

public IEnumerator wait()
    {
        leftSwipe = true;
        yield return new WaitForSeconds(0.5f);
        leftSwipe = false;
    }



    void Start()
    {

    }

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



        closestPlatform = FindClosestPlatform();


        if ((closestPlatform = left) && (leftSwipe = false))
        {
            strike = 1;
        }


        if (Input.touchCount > 0)
        {
            Touch touch = Input.GetTouch(0);

            if (touch.phase == TouchPhase.Began)
            {
                startTime = Time.time;
                startPos = touch.position;
            }
            else if (touch.phase == TouchPhase.Ended)
            {
                endTime = Time.time;
                endPos = touch.position;

                swipeDistance = (endPos - startPos).magnitude;
                swipeTime = endTime - startTime;

                if (swipeTime < maxTime && swipeDistance > minSwipeDistance)
                {
                    swipe();
                }
            }

        }

    }


    void swipe()
    {












            Vector2 distance = endPos - startPos;
            if (Mathf.Abs(distance.x) > Mathf.Abs(distance.y))
            {
                Debug.Log("Horizontal Swipe");
                if (distance.x > 0)
                {
                    Debug.Log("Right Swipe");
                }
                if (distance.x < 0)
                {
                    Debug.Log("Left Swipe");

                    StartCoroutine(wait());


                }

            }

            else if (Mathf.Abs(distance.x) < Mathf.Abs(distance.y))
            {
                Debug.Log("Vertical Swipe");
                if (distance.y > 0)
                {
                    Debug.Log("Up Swipe");
                }
                if (distance.y < 0)
                {
                    Debug.Log("Down Swipe");
                }
            }


        }




    }

Answer 1

if ((closestPlatform = left) && (leftSwipe = false)) { strike = 1; }

= is assignment. == is comparison.

This will always be false, as it assigns false to leftSwipe and then uses it as the operand to && .

You meant to write

if ((closestPlatform == left) && !leftSwipe) { strike = 1; }

Note that it is poor style to compare bools against true and false . Instead of if(x == true) just say if (x) . You wouldn't say "if the statement that it is raining is a true statement then close the window". You'd just say "if it is raining then close the window". Instead of if (x == false) just say if (!x) . You wouldn't say "if the statement that it is raining is a false statement then open the window". You'd say "if it is not raining then open the window". Keep it simple and you'll make fewer mistakes.

Answer 2

You're using assignment, not comparison.

if ((closestPlatform = left) && (leftSwipe = false)) { strike = 1; }

Replace "=" with "==".

Answer 3

您正在使用赋值运算符，而不是使用比较运算符。

if ((closestPlatform == left) && (leftSwipe == false)) { strike = 1; }