旋转后禁用 UIScrollView 分页

Question

以下是我使用 UIScrollView 使用 AutoLayout 启用分页的 App Tour 代码 (Masonry) 它在纵向中工作正常，但是当我旋转分页时被禁用，因此在横向中不起作用。然后它在肖像模式下也不起作用。有人可以帮忙看看这里出了什么问题吗？

- (void)viewDidLoad {
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor clearColor];

    self.scrollView = [UIScrollView new];
    self.scrollView.backgroundColor = [UIColor clearColor];
    self.scrollView.scrollEnabled = YES;
    self.scrollView.pagingEnabled = YES;
    self.scrollView.delegate = self;
    self.scrollView.showsHorizontalScrollIndicator = NO;
    [self.view addSubview:self.scrollView];

    [self.scrollView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.edges.equalTo(self.view);
    }];

    UIImageView *esImageview1 = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"CommonResources.bundle/page1"]];
    esImageview1.contentMode = UIViewContentModeScaleAspectFit;
    esImageview1.backgroundColor = [UIColor clearColor];
    esImageview1.userInteractionEnabled = YES;
    [self.scrollView addSubview:esImageview1];

    [esImageview1 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.top.bottom.equalTo(self.scrollView);
        make.width.height.equalTo(self.view);
    }];

    UIImageView *esImageview2 = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"CommonResources.bundle/page2"]];
    esImageview2.contentMode = UIViewContentModeScaleAspectFit;
    esImageview2.backgroundColor = [UIColor clearColor];
    esImageview2.userInteractionEnabled = YES;
    [self.scrollView addSubview:esImageview2];

    [esImageview2 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(esImageview1.mas_right);
        make.top.bottom.equalTo(self.scrollView);
        make.width.height.equalTo(self.view);
    }];

    UIImageView *esImageview3 = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"CommonResources.bundle/page3"]];
    esImageview3.contentMode = UIViewContentModeScaleAspectFit;
    esImageview3.backgroundColor = [UIColor clearColor];
    esImageview3.userInteractionEnabled = YES;
    [self.scrollView addSubview:esImageview3];

    [esImageview3 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.equalTo(esImageview2.mas_right);
        make.top.bottom.equalTo(self.scrollView);
        make.width.height.equalTo(self.view);
    }];

    self.pageControl = [UIPageControl new];
    self.pageControl.numberOfPages = 3;
    self.pageControl.currentPage = 0;
    self.pageControl.backgroundColor = [UIColor clearColor];
    [self.view addSubview:self.pageControl];

    [self.pageControl mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.equalTo(self.view);
        make.height.equalTo(@40);
        make.top.equalTo(self.view).with.offset(40);
    }];

    UILabel *titleLabel = [UILabel new];
    titleLabel.text = @"App Tour";
    titleLabel.backgroundColor = [UIColor clearColor];
    titleLabel.textColor = [UIColor whiteColor];
    titleLabel.font = [UIFont fontWithName:@"Helvetica-Light" size:16];
    titleLabel.textAlignment = NSTextAlignmentCenter;
    [self.view addSubview:titleLabel];

    [titleLabel mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.right.equalTo(self.view);
        make.height.equalTo(@40);
        make.top.equalTo(self.view).with.offset(20);
    }];

    UIButton *doneButton = [UIButton new];
    [doneButton.titleLabel setFont:[UIFont fontWithName:@"Helvetica-Light" size:16]];
    [doneButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [doneButton setTitleColor:[UIColor grayColor] forState:UIControlStateHighlighted];
    [doneButton setTitle:@"Done" forState:UIControlStateNormal];
    [doneButton addTarget:self action:@selector(doneButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
    doneButton.backgroundColor = [UIColor clearColor];
    [self.view addSubview:doneButton];

    [doneButton mas_makeConstraints:^(MASConstraintMaker *make) {
        make.right.equalTo(self.view);
        make.height.equalTo(@40);
        make.width.equalTo(@70);
        make.top.equalTo(self.view).with.offset(20);
    }];
}

- (void)doneButtonPressed:(id)sender {
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (void)viewDidLayoutSubviews {
    [super viewDidLayoutSubviews];
    self.scrollView.contentSize = CGSizeMake(self.view.frame.size.width*self.pageControl.numberOfPages, self.view.frame.size.height);
}

- (void)scrollViewDidScroll:(UIScrollView *)sender {
    CGFloat pageWidth = self.scrollView.frame.size.width;
    int page = floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
    self.pageControl.currentPage = page;
}

Answer 1

我猜它被另一个视图或类似的东西掩盖了。尝试继承 UIScrollView 并实现以下方法来检查它是否完全响应您的触摸。

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    NSLog(@"OMG TOUCHES WORK, NOW WHAT?");
}

您可以通过强制它在前面轻松检查它是否被掩盖。在包含 UIScrollView 的 UIViewController 中的回调中调用这行代码进行旋转。它应该可以解决问题。您可能必须为控制器子类化 UIView 并将此方法放在 didLayoutSubviews 方法中，不太确定，这取决于您的实现。

[self.view bringSubViewToFront:self.scrollView];

还要检查旋转前后的框架和边界，看看是否有什么不合适的地方

Answer 2

我只是想在 didRotateFromInterfaceOrientation 委托中重置 Scrollview 的内容大小。不知道为什么，因为当我旋转时，videDidLayoutSubview 已经在我已经重置内容大小的地方被调用了。

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    self.scrollView.contentSize = CGSizeMake(self.view.frame.size.width*self.pageControl.numberOfPages, self.view.frame.size.height);
}