检测滑动手势方向 [英] Detect swipe gesture direction

问题描述

这是我的代码，可以尝试模拟滑动手势，因此当我构建到移动设备时，我知道它会工作.什么都没有记录，我对为什么它似乎不起作用感到困惑.我希望它在我刷过RTL(从右到左)或LTR(从左到右)的控制台中打印出来.我看不到我在做什么错.

That is my code to try and simulate a swipe gesture so when I build to mobile I know it will work. Nothing is being logged and I am confused on why it seems to not work. I want it to print out in the console that I either swiped RTL (Right to Left) or LTR (Left to right). I do not see what I am doing wrong.

void Update()
{
    if (Input.GetMouseButtonDown(0))
    {
        startPosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
    }
    if (Input.GetMouseButtonUp(0))
    {
        endPosition = Camera.main.ScreenToWorldPoint(Input.mousePosition);
    }

    if (startPosition != endPosition && startPosition != Vector3.zero && endPosition != Vector3.zero)
    {
        float deltaX = endPosition.x - startPosition.x;
        float deltaY = endPosition.y - startPosition.y;
        if ((deltaX > 5.0f || deltaX < -5.0f) && (deltaY >= -1.0f || deltaY <= 1.0f))
        {
            if (startPosition.x < endPosition.x)
            {
                print("LTR");
            }
            else
            {
                print("RTL");
            }
        }
        startPosition = endPosition = Vector3.zero;
    }
}

推荐答案

我可以在您的代码中发现一些问题.将Vector3与==或!=进行比较不是一个好主意.大概比较是可以的.您正在移动平台上使用Input.GetMouseButtonDown.

I can spot some few problems in your code. It's not a good idea to compare Vector3 with == or !=. Approximate comparison is fine. You are using Input.GetMouseButtonDown on a mobile platform.

您需要使用 Input.touches 来执行此操作.循环播放，将起始位置存储在 TouchPhase.Began 中在 TouchPhase.Ended 中.然后，您可以使用这两个变量来确定手指的方向.

You need to use Input.touches to do this. Loop over it, store the beginning position in TouchPhase.Began and then the end position in TouchPhase.Ended. You can then use both variables to figure it which direction the finger went.

即使未通过 TouchPhase.Moved .您可以通过启用detectSwipeOnlyAfterRelease布尔变量来禁用它.您还可以修改SWIPE_THRESHOLD的灵敏度.

The code below detects swipe direction even when the finger is not yet released with the help of TouchPhase.Moved. You can disable that by enabling the detectSwipeOnlyAfterRelease boolean variable. You can also modify SWIPE_THRESHOLD for sensitivity.

public class SwipeDetector : MonoBehaviour
{
    private Vector2 fingerDown;
    private Vector2 fingerUp;
    public bool detectSwipeOnlyAfterRelease = false;

    public float SWIPE_THRESHOLD = 20f;

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

        foreach (Touch touch in Input.touches)
        {
            if (touch.phase == TouchPhase.Began)
            {
                fingerUp = touch.position;
                fingerDown = touch.position;
            }

            //Detects Swipe while finger is still moving
            if (touch.phase == TouchPhase.Moved)
            {
                if (!detectSwipeOnlyAfterRelease)
                {
                    fingerDown = touch.position;
                    checkSwipe();
                }
            }

            //Detects swipe after finger is released
            if (touch.phase == TouchPhase.Ended)
            {
                fingerDown = touch.position;
                checkSwipe();
            }
        }
    }

    void checkSwipe()
    {
        //Check if Vertical swipe
        if (verticalMove() > SWIPE_THRESHOLD && verticalMove() > horizontalValMove())
        {
            //Debug.Log("Vertical");
            if (fingerDown.y - fingerUp.y > 0)//up swipe
            {
                OnSwipeUp();
            }
            else if (fingerDown.y - fingerUp.y < 0)//Down swipe
            {
                OnSwipeDown();
            }
            fingerUp = fingerDown;
        }

        //Check if Horizontal swipe
        else if (horizontalValMove() > SWIPE_THRESHOLD && horizontalValMove() > verticalMove())
        {
            //Debug.Log("Horizontal");
            if (fingerDown.x - fingerUp.x > 0)//Right swipe
            {
                OnSwipeRight();
            }
            else if (fingerDown.x - fingerUp.x < 0)//Left swipe
            {
                OnSwipeLeft();
            }
            fingerUp = fingerDown;
        }

        //No Movement at-all
        else
        {
            //Debug.Log("No Swipe!");
        }
    }

    float verticalMove()
    {
        return Mathf.Abs(fingerDown.y - fingerUp.y);
    }

    float horizontalValMove()
    {
        return Mathf.Abs(fingerDown.x - fingerUp.x);
    }

    //////////////////////////////////CALLBACK FUNCTIONS/////////////////////////////
    void OnSwipeUp()
    {
        Debug.Log("Swipe UP");
    }

    void OnSwipeDown()
    {
        Debug.Log("Swipe Down");
    }

    void OnSwipeLeft()
    {
        Debug.Log("Swipe Left");
    }

    void OnSwipeRight()
    {
        Debug.Log("Swipe Right");
    }
}

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