Question

我知道UIRotateGestureRecognizer已经是iOS的一部分了。但这个手势需要两个手指。我如何才能实现一个只需要一根手指的类似手势识别器？在AppStore中有一款游戏 - Gyrotate有很好的实现。任何线索都值得赞赏。 THX。

Answer 1

Kirby Turner有一个完整的单指旋转手势识别器here。

Answer 2

这是代码 - 它可以在我的模拟器上运行。 Mark回答你是否正在寻找。

    // On new touch, start a new array of points
- (void) touchesBegan:(NSSet *) touches withEvent:(UIEvent *) event
{
    self.points = [NSMutableArray array];
    CGPoint pt = [[touches anyObject] locationInView:self];
    [self.points addObject:[NSValue valueWithCGPoint:pt]];
}

// Add each point to the array
- (void) touchesMoved:(NSSet *) touches withEvent:(UIEvent *) event
{
    CGPoint pt = [[touches anyObject] locationInView:self];
    [self.points addObject:[NSValue valueWithCGPoint:pt]];
    [self setNeedsDisplay];
}

// At the end of touches, determine whether a circle was drawn
- (void) touchesEnded:(NSSet *) touches withEvent:(UIEvent *) event
{
    if (!self.points) return;
    if (self.points.count < 3) return;

    // Test 1: The start and end points must be between 60 pixels of each other
    CGRect tcircle;
    if (distance(POINT(0), POINT(self.points.count - 1)) < 60.0f)
        tcircle = [self centeredRectangle];

    // Test 2: Count the distance traveled in degrees. Must fall within 45 degrees of 2 PI
    CGPoint center = CGPointMake(CGRectGetMidX(tcircle), CGRectGetMidY(tcircle));
    float distance = ABS(acos(dotproduct(centerPoint(POINT(0), center), centerPoint(POINT(1), center))));
    for (int i = 1; i < (self.points.count - 1); i++)
        distance += ABS(acos(dotproduct(centerPoint(POINT(i), center), centerPoint(POINT(i+1), center))));
    if ((ABS(distance - 2 * M_PI) < (M_PI / 4.0f))) circle = tcircle;

    [self setNeedsDisplay];
}

Answer 3

尝试浏览UIGestureRecognizer课程。您应该可以使用UIGestureRecognizerDelegate

对其进行自定义

Answer 4

我使用 OneFingerRotation ，比例，调整大小和关闭功能实施 IQStickerView

功能 的： -

1）一个手指旋转刻度。

2）单手调整大小。

3）启用/ Desable旋转，缩放，调整属性大小。

4）自动管理多个IQStickerView。

5）也可以使用UIScrollView。

6）快速响应。

github repositor在这里： - https://github.com/hackiftekhar/IQStickerView

Answer 5

使用平移手势识别器实现，这是使用手势识别器附加到的另一个UIView，但它应该与附加到您想要旋转的视图一起使用。

- (void) gestureRotateButtonPan:(UIPanGestureRecognizer*) gestureRecognizer {

    switch (gestureRecognizer.state) {
        case UIGestureRecognizerStatePossible:
            break;
        case UIGestureRecognizerStateBegan:
        {
            CGPoint location = [gestureRecognizer translationInView:[gestureRecognizer view]];
            _touchRotateStartPoint = [self convertPoint:location fromView:[gestureRecognizer view]];
        }
            break;
        case UIGestureRecognizerStateChanged:
        {
            CGPoint imageLocation = CGPointMake(self.mainImageView.transform.tx + self.mainImageView.center.x
                                                , self.mainImageView.transform.ty + self.mainImageView.center.y);
            CGPoint buttonLocation = [gestureRecognizer translationInView:self];
            buttonLocation.x += _touchRotateStartPoint.x;
            buttonLocation.y += _touchRotateStartPoint.y;

            CGFloat currentRotation = atan2(buttonLocation.y - imageLocation.y, buttonLocation.x - imageLocation.x)
                                        - atan2(_touchRotateStartPoint.y - imageLocation.y, _touchRotateStartPoint.x - imageLocation.x);

            CGFloat rotation = -(_lastRotation - currentRotation);
            CGAffineTransform currentTransform = self.mainImageView.transform;
            CGAffineTransform rotatedTransform = CGAffineTransformRotate(currentTransform, rotation);
            self.mainImageView.transform = rotatedTransform;

            [self setNeedsDisplay];
        }
            break;
        case UIGestureRecognizerStateCancelled:
        case UIGestureRecognizerStateEnded:
            _lastRotation = 0.0;
            break;
        case UIGestureRecognizerStateFailed:
            break;
        default:
            break;
    }
}

如何实现单指旋转手势识别器？

5 个答案: