检测滑动手势方向

Question

这是我尝试模拟滑动手势的代码，因此当我构建到移动设备时，我知道它会起作用。没有任何记录，我对为什么它似乎不起作用感到困惑。我希望它在控制台中打印出来，我要么刷了RTL（从右到左）或LTR（从左到右）。我看不出我做错了什么。

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;
    }
}

Answer 1

我可以在您的代码中发现一些问题。将Vector3 与== 或!= 进行比较并不是一个好主意。近似比较就好了。您在移动平台上使用Input.GetMouseButtonDown。

您需要使用Input.touches 来执行此操作。循环遍历它，将开始位置存储在TouchPhase.Began 中，然后将结束位置存储在TouchPhase.Ended 中。然后，您可以使用这两个变量来确定手指的方向。

在TouchPhase.Moved 的帮助下，即使手指尚未释放，下面的代码也会检测滑动方向。您可以通过启用 detectSwipeOnlyAfterRelease 布尔变量来禁用它。你也可以修改SWIPE_THRESHOLD的敏感度。

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");
    }
}

Answer 2

感谢程序员，我使用了他的建议并编写了一个小组件，它可以与鼠标和触摸一起使用。鼠标将允许您在 PC 上调试应用程序。我还添加了以秒为单位的时间阈值，因为滑动不能太长。

using System;
using UnityEngine;
using UnityEngine.Events;

public class SwipeManager : MonoBehaviour {

  public float swipeThreshold = 50f;
  public float timeThreshold = 0.3f;

  public UnityEvent OnSwipeLeft;
  public UnityEvent OnSwipeRight;
  public UnityEvent OnSwipeUp;
  public UnityEvent OnSwipeDown;

  private Vector2 fingerDown;
  private DateTime fingerDownTime;
  private Vector2 fingerUp;
  private DateTime fingerUpTime;

  private void Update () {
    if (Input.GetMouseButtonDown(0)) {
      this.fingerDown = Input.mousePosition;
      this.fingerUp = Input.mousePosition;
      this.fingerDownTime = DateTime.Now;
    }
    if (Input.GetMouseButtonUp(0)) {
      this.fingerDown = Input.mousePosition;
      this.fingerUpTime = DateTime.Now;
      this.CheckSwipe();
    }
    foreach (Touch touch in Input.touches) {
      if (touch.phase == TouchPhase.Began) {
        this.fingerDown = touch.position;
        this.fingerUp = touch.position;
        this.fingerDownTime = DateTime.Now;
      }
      if (touch.phase == TouchPhase.Ended) {
        this.fingerDown = touch.position;
        this.fingerUpTime = DateTime.Now;
        this.CheckSwipe();
      }
    }
  }

  private void CheckSwipe() {
    float duration = (float)this.fingerUpTime.Subtract(this.fingerDownTime).TotalSeconds;
    if (duration > this.timeThreshold) return;

    float deltaX = this.fingerDown.x - this.fingerUp.x;
    if (Mathf.Abs(deltaX) > this.swipeThreshold) {
      if (deltaX > 0) {
        this.OnSwipeRight.Invoke();
        //Debug.Log("right");
      } else if (deltaX < 0) {
        this.OnSwipeLeft.Invoke();
        //Debug.Log("left");
      }
    }

    float deltaY = fingerDown.y - fingerUp.y;
    if (Mathf.Abs(deltaY) > this.swipeThreshold) {
      if (deltaY > 0) {
        this.OnSwipeUp.Invoke();
        //Debug.Log("up");
      } else if (deltaY < 0) {
        this.OnSwipeDown.Invoke();
        //Debug.Log("down");
      }
    }

    this.fingerUp = this.fingerDown;
  }
}

Answer 3

为更精确的控制器（和更少的代码！=D）修改了开发者的方法：

using System;
using UnityEngine;
using UnityEngine.Events;
using Utilities;

public class SwipeManager : MonoBehaviour {

  public float swipeThreshold = 40f;
  public float timeThreshold = 0.3f;

  public UnityEvent onSwipeLeft;
  public UnityEvent onSwipeRight;
  public UnityEvent onSwipeUp;
  public UnityEvent onSwipeDown;

  private Vector2 _fingerDown;
  private DateTime _fingerDownTime;
  private Vector2 _fingerUp;
  private DateTime _fingerUpTime;

  private void Update () {
    if (Input.GetMouseButtonDown(0)) {
      _fingerDown = Input.mousePosition;
      _fingerUp = Input.mousePosition;
      _fingerDownTime = DateTime.Now;
    }

    if (Input.GetMouseButtonUp(0)) {
      _fingerDown = Input.mousePosition;
      _fingerUpTime = DateTime.Now;
      CheckSwipe();
    }

    foreach (var touch in Input.touches) {
      if (touch.phase == TouchPhase.Began) {
        _fingerDown = touch.position;
        _fingerUp = touch.position;
        _fingerDownTime = DateTime.Now;
      }

      if (touch.phase == TouchPhase.Ended) {
        _fingerDown = touch.position;
        _fingerUpTime = DateTime.Now;
        CheckSwipe();
      }
    }
  }

  private void CheckSwipe() {
    var duration = (float)_fingerUpTime.Subtract(_fingerDownTime).TotalSeconds;
    var dirVector = _fingerUp - _fingerDown;

    if (duration > timeThreshold) return;
    if (dirVector.magnitude < swipeThreshold) return;

    var direction = dirVector.Rotation(180f).Round();

    print(direction);

    if (direction >= 45 && direction < 135) onSwipeUp.Invoke();
    else if (direction >= 135 && direction < 225) onSwipeRight.Invoke();
    else if (direction >= 225 && direction < 315) onSwipeDown.Invoke();
    else if (direction >= 315 && direction < 360 || direction >= 0 && direction < 45) onSwipeLeft.Invoke();
  }
}

Answer 4

我搜索了同样的东西，发现创建资产以方便滑动检测并与社区分享是合理的。所以这里是github。我的解决方案支持不同的用例，包括：8 方向滑动检测、4 方向、2 方向（左右或上下）、六边形网格上的滑动。所有列出的都包含为预设，但您也可以将其配置为检测任意数量的 Vector3 方向。所以 ti 真的很灵活。此外，您可以尝试WebGL build 或查看video tutorial。如果您尝试一下，请告诉我（通过 youtube 评论，或查看 github 上的联系人部分），它是否适合您的情况，是否足够舒适。

Answer 5

Try this Out.  
I hope this helps.




void Update(){
if (Input.GetMouseButtonDown(0)){
    startPosition = Input.mousePosition;
}
if (Input.GetMouseButtonUp(0)){
    float swipe = startPosition.x - Input.mousePosition.x;
}


        if (swipe < 0)
        {
            print("LTR");
        } else{
            print("RTL");
        }
    }

}
}