Pan手势干扰卷轴

Question

我有三个视图控制器，它们是UIScrollView的一部分。我希望能够在三个视图之间滑动，尽管其中一个视图控制器有一个UIPanGestureRecognizer。我使用这个pan手势识别器，允许用户上下拖动手指来增加和降低矩形UIView的高度。因此，这个UIPanGestureRecognizer只需要知道向上/向下的摇摄，滚动视图可以使用水平摇摄。

这方面的一个例子是，就像主屏幕一样；你可以左右滑动，也可以向下滑动以获得聚光灯。我想要这种机制。

这是我的密码：

- (void)pan:(UIPanGestureRecognizer *)aPan; // When pan guesture is recognised
{
CGPoint location = [aPan locationInView:self.view]; // Location of finger on screen
CGRect secondRect = CGRectMake(210.0, 45.0, 70.0, 325.0); // Rectangles of maximimum bar area
CGRect minuteRect = CGRectMake(125.0, 45.0, 70.0, 325.0);
CGRect hourRect = CGRectMake(41.0, 45.0, 70.0, 325.0);

if (CGRectContainsPoint(secondRect, location)) { // If finger is inside the 'second' rectangle

    CGPoint currentPoint = [aPan locationInView:self.view];

    currentPoint.y -= 80;  // Make sure animation doesn't go outside the bars' rectangle

    if (currentPoint.y < 0) {
    currentPoint.y = 0;
    }
    else if (currentPoint.y > 239) {
    currentPoint.y = 239;
    }

    currentPoint.y = 239.0 - currentPoint.y;

    CGFloat pointy = currentPoint.y - fmod(currentPoint.y, 4.0);

    [UIView animateWithDuration:0.01f  // Animate the bars to rise as the finger moves up and down
                     animations:^{
                         CGRect oldFrame = secondBar.frame;
                         secondBar.frame = CGRectMake(oldFrame.origin.x, (oldFrame.origin.y - (pointy - secondBar.frame.size.height)), oldFrame.size.width, (pointy));
                     }];

    CGFloat result = secondBar.frame.size.height - fmod(secondBar.frame.size.height, 4.0);

    secondInt = (result / 4.0); // Update labels with new time

    self->secondLabel.text = [NSString stringWithFormat:@"%02d", secondInt];
}

对于三个独立的矩形UIViews，代码基本上是重复的。

如果有人能告诉我如何让主屏幕式的摇摄/滑动进入我的应用程序，那就太好了！！

Answer 1

好吧，下面是简短的答案：

您必须使用UIGestureRecognizer的方法-requireGestureRecognizerToFail:。

，这是一个很长的答案：

如果的pan手势识别器失败，您必须使滚动视图的pan手势识别器成功。然而，这个手势(TimerViewController的手势)应该只有当初始运动垂直时才能成功。如果是水平移动，则应该失败。要实现这一点，我们必须对UIPanGestureRecognizer进行子类化，并对其进行修改以满足这些需求。下面是您必须做的事情：

1. 无视你从我以前的回答中所做的改变
2. 将VerticalPanGestureRecognizer添加到项目中。
3. 如图所示修改TimerViewController。
4. 如图所示修改ScrollViewController。

VerticalPanGestureRecognizer.h

#import <UIKit/UIKit.h>
#import <UIKit/UIGestureRecognizerSubclass.h>

@interface VerticalPanGestureRecognizer : UIPanGestureRecognizer

@end

VerticalPanGestureRecognizer.m

#import "VerticalPanGestureRecognizer.h"

@interface VerticalPanGestureRecognizer ()

@property (nonatomic, assign) CGPoint origLoc;

@end

@implementation VerticalPanGestureRecognizer

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    self.origLoc = [[touches anyObject] locationInView:self.view.superview];
    [super touchesBegan:touches withEvent:event];
}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

    if (self.state == UIGestureRecognizerStatePossible) {
        CGPoint loc = [[touches anyObject] locationInView:self.view.superview];
        CGFloat deltaX = fabs(loc.x - self.origLoc.x);
        CGFloat deltaY = fabs(loc.y - self.origLoc.y);
        if (deltaY < deltaX)
            self.state = UIGestureRecognizerStateFailed;
    }

    [super touchesMoved:touches withEvent:event];
}

@end

TimerViewController.h

// Your imports here

@interface TimerViewController : UIViewController

{
    // Your ivars here
}

// Add the following property
@property (nonatomic, strong) UIPanGestureRecognizer *pan;

// Your methods here

@end

TimerViewController.m

#import "TimerViewController.h"
#import "VerticalPanGestureRecognizer.h"

@implementation TimerViewController
@synthesize pan = _pan;

// prefersStatusBarHidden method here

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil // Initialise view controller
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    if (self) {

        // Instantiate the pan gesture as "VerticalPanGestureRecognizer"
        self.pan = [[VerticalPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)]; // Create recogniser for a pan guesture
        self.pan.maximumNumberOfTouches = self.pan.minimumNumberOfTouches = 1;
        [self.view addGestureRecognizer:self.pan];
    }

    return self;
}

// The rest of your code here

@end

ScrollViewController.m

- (void)viewDidLoad
{
    // Your code here

    TimerViewController *tvc = [[TimerViewController alloc]init];
    CGRect frame = tvc.view.frame;
    frame.origin.x = 320;
    tvc.view.frame = frame;

    // Add the following line 
    [self.scrollView.panGestureRecognizer requireGestureRecognizerToFail:tvc.pan];

    [self addChildViewController:tvc];
    [self.scrollView addSubview:tvc.view];
    [tvc didMoveToParentViewController:self];

    // More code here
}

这种新方法非常有效。我测试过了。如果你还有其他问题，请告诉我。

干杯!

更新

为了回答你在评论上发布的问题，下面是你必须做的事情：

- (void)viewDidLoad
{
    [super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.

    BarsViewController *bvc = [[BarsViewController alloc]init];
    [self addChildViewController:bvc];
    [self.scrollView addSubview:bvc.view];
    [bvc didMoveToParentViewController:self];

    TimerViewController *tvc = [[TimerViewController alloc]init];
    CGRect frame = tvc.view.frame;
    frame.origin.x = 320;
    tvc.view.frame = frame;

    [self.scrollView.panGestureRecognizer requireGestureRecognizerToFail:tvc.pan];
    [self addChildViewController:tvc];
    [self.scrollView addSubview:tvc.view];
    [tvc didMoveToParentViewController:self];

    StopwatchViewController *svc = [[StopwatchViewController alloc] init];
    frame = svc.view.frame;
    frame.origin.x = 320*2;
    svc.view.frame = frame;

    [self addChildViewController:svc];
    [self.scrollView addSubview:svc.view];
    [svc didMoveToParentViewController:self];

    self.scrollView.contentSize = CGSizeMake(320*3, self.view.frame.size.height);
    self.scrollView.pagingEnabled = YES;

    [self.scrollView setShowsHorizontalScrollIndicator:NO];
}

再次，我测试了它，它是有效的。您只需为栏添加手势识别器即可。