40

私のアプリには画像ビューがあります。その画像ビューにPANジェスチャを追加しています。

これは正常に機能しています。

画像ビューは横向きモードです。

ユーザーが右方向にパンしている間はラベルのカウントを増やし、ユーザーが左方向にパンしている間はそのカウントを減らしたい。

私はたくさんググったが、これに対する解決策を見つけられなかった。

ユーザーがパンしている方向（左/右）を検出する方法を教えてもらえますか？

4

7 に答える 7

94

ジェスチャレコグナイザのターゲットセレクタで、次を使用します- (CGPoint)velocityInView:(UIView *)view;。

- (void)panRecognized:(UIPanGestureRecognizer *)rec
{
    CGPoint vel = [rec velocityInView:self.view];
    if (vel.x > 0)
    {
        // user dragged towards the right
        counter++;
    }
    else
    {
        // user dragged towards the left
        counter--;
    }
}

追伸：この方法については、約1時間まで知りませんでした。3分前。Googleの最初のヒットの1つは、Appleの公式ドキュメントでした。

于 2012-08-02T12:25:23.943 に答える
37

このようなもの：

- (void)pan:(UIPanGestureRecognizer *)sender
{

    typedef NS_ENUM(NSUInteger, UIPanGestureRecognizerDirection) {
        UIPanGestureRecognizerDirectionUndefined,
        UIPanGestureRecognizerDirectionUp,
        UIPanGestureRecognizerDirectionDown,
        UIPanGestureRecognizerDirectionLeft,
        UIPanGestureRecognizerDirectionRight
    };

    static UIPanGestureRecognizerDirection direction = UIPanGestureRecognizerDirectionUndefined;

    switch (sender.state) {

        case UIGestureRecognizerStateBegan: {

            if (direction == UIPanGestureRecognizerDirectionUndefined) {

                CGPoint velocity = [sender velocityInView:recognizer.view];

                BOOL isVerticalGesture = fabs(velocity.y) > fabs(velocity.x);

                if (isVerticalGesture) {
                    if (velocity.y > 0) {
                        direction = UIPanGestureRecognizerDirectionDown;
                    } else {
                        direction = UIPanGestureRecognizerDirectionUp;
                    }
                }

                else {
                    if (velocity.x > 0) {
                        direction = UIPanGestureRecognizerDirectionRight;
                    } else {
                        direction = UIPanGestureRecognizerDirectionLeft;
                    }
                }
            }

            break;
        }

        case UIGestureRecognizerStateChanged: {
            switch (direction) {
                case UIPanGestureRecognizerDirectionUp: {
                    [self handleUpwardsGesture:sender];
                    break;
                }
                case UIPanGestureRecognizerDirectionDown: {
                    [self handleDownwardsGesture:sender];
                    break;
                }
                case UIPanGestureRecognizerDirectionLeft: {
                    [self handleLeftGesture:sender];
                    break;
                }
                case UIPanGestureRecognizerDirectionRight: {
                    [self handleRightGesture:sender];
                    break;
                }
                default: {
                    break;
                }
            }
        }

        case UIGestureRecognizerStateEnded: {
            direction = UIPanGestureRecognizerDirectionUndefined;   
            break;
        }

        default:
            break;
    }

}

- (void)handleUpwardsGesture:(UIPanGestureRecognizer *)sender
{
    NSLog(@"Up");
}

- (void)handleDownwardsGesture:(UIPanGestureRecognizer *)sender
{
    NSLog(@"Down");
}

- (void)handleLeftGesture:(UIPanGestureRecognizer *)sender
{
    NSLog(@"Left");
}

- (void)handleRightGesture:(UIPanGestureRecognizer *)sender
{
    NSLog(@"Right");
}
于 2014-02-04T12:41:42.087 に答える
20

Swiftでの私の以前の答え

public enum Direction: Int {
    case Up
    case Down
    case Left
    case Right

    public var isX: Bool { return self == .Left || self == .Right }
    public var isY: Bool { return !isX }
}

public extension UIPanGestureRecognizer {

    public var direction: Direction? {
        let velocity = velocityInView(view)
        let vertical = fabs(velocity.y) > fabs(velocity.x)
        switch (vertical, velocity.x, velocity.y) {
        case (true, _, let y) where y < 0: return .Up
        case (true, _, let y) where y > 0: return .Down
        case (false, let x, _) where x > 0: return .Right
        case (false, let x, _) where x < 0: return .Left
        default: return nil
        }
    }
}
于 2016-06-08T09:21:00.827 に答える
19

クリーンアップされたSwift5バージョンと、使用例を次に示します。

public enum PanDirection: Int {
    case up, down, left, right
    public var isVertical: Bool { return [.up, .down].contains(self) }
    public var isHorizontal: Bool { return !isVertical }
}

public extension UIPanGestureRecognizer {

   var direction: PanDirection? {
        let velocity = self.velocity(in: view)
        let isVertical = abs(velocity.y) > abs(velocity.x)
        switch (isVertical, velocity.x, velocity.y) {
        case (true, _, let y) where y < 0: return .up
        case (true, _, let y) where y > 0: return .down
        case (false, let x, _) where x > 0: return .right
        case (false, let x, _) where x < 0: return .left
        default: return nil
        }
    }

}

@IBAction func pan(_ recognizer: UIPanGestureRecognizer) {        
    if let direction = recognizer.direction {
        if direction.isVertical {
            //do what you want when pan is vertical
        } else if direction == .left {
            //do what you want when pan is left
        }
    }
}
于 2017-04-12T20:13:56.133 に答える
2

Swift3でAdamWaiteバージョンを書き直します 

public enum PanDirection: Int {
    case up,
    down,
    left,
    right

    public var isX: Bool {
        return self == .left || self == .right
    }

    public var isY: Bool {
        return !isX
    }
}

extension UIPanGestureRecognizer {
    var direction: PanDirection? {
        let velocity = self.velocity(in: view)
        let vertical = fabs(velocity.y) > fabs(velocity.x)
        switch (vertical, velocity.x, velocity.y) {
        case (true, _, let y):
            return y < 0 ? .up : .down

        case (false, let x, _):
            return x > 0 ? .right : .left
        }
    }
}
于 2017-03-27T15:03:56.597 に答える
1

上記のAdamのSwiftバージョンには誤りがあることに注意してください。.upはy<0の場合に戻り、.downはy> 0の場合に戻ります（これらは逆になります）。

それで：

//MARK: - Direction
internal enum Direction {
    case up
    case down
    case left
    case right
}

//MARK: - UIPanGestureRecognizer
internal extension UIPanGestureRecognizer {
    internal var direction: Direction? {
        let velocity = velocityInView(view)
        let isVertical = fabs(velocity.y) > fabs(velocity.x)

        switch (isVertical, velocity.x, velocity.y) {
            case (true, _, let y) where y < 0: return .up
            case (true, _, let y) where y > 0: return .down
            case (false, let x, _) where x > 0: return .right
            case (false, let x, _) where x < 0: return .left
            default: return nil
        }
    }
}
于 2016-07-09T07:58:39.000 に答える
0

判断するのvelocityは私には敏感すぎて、ユーザーは簡単にタッピング画面と小さな部分をパンすることを混ぜ合わせました。

だから私はカスタムを使用しますUIPanGestureRecognizer。スウィフト5

enum Orientation{
    case lhs, rhs, `default`
}



class HPan: UIPanGestureRecognizer {

    var first: CGPoint?
    var orient = .default

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesBegan(touches, with: event)

        state = .began
        first = touches.first?.location(in: view?.window)
    }


    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesMoved(touches, with: event)
        if state == .cancelled{
            return
        }
        if let location = touches.first?.location(in: view?.window), let begin = first{
          let magicDistance: CGFloat = 20
          if location.x - begin.x > magicDistance{
               orient = .rhs
               state = .ended
          }  
          else if begin.x - location.x > magicDistance{
               orient = .lhs
               state = .ended
          }  
        }

    }



    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesEnded(touches, with: event)
        state = .ended
    }



    override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent) {
        super.touchesCancelled(touches, with: event)
        state = .cancelled
    }


    override func reset() {
        super.reset()

        state = .possible
        isRight = false
        orient = .default
    }
}

このように呼び出します：

@objc func push(_ gesture: RightPan){
        if gesture.state == UIGestureRecognizer.State.ended{
            switch gesture.orient{
                case .lhs:
                     counter -= 1
                case .rhs:
                     counter += 1
                default:
                    ()        
            }
        }

    }
于 2019-12-08T16:25:30.023 に答える