iphone - 从 FlipsideViewController 返回后 UIScrollView 无响应

Question

我写了一个简单的例子，我有一个实用程序项目，上面有一个 UIScrollView。当我单击信息按钮翻转屏幕并返回时，UIScrollView 现在没有响应。不仅如此，我还特意将滚动条放在左上角的 Interface Builder 中，然后以编程方式将其设置在中间。当我从反面回来时，它向上移动到左上角并且没有反应。为什么？

这是我的.h 文件:

  #import "POCFlipsideViewController.h"

    @interface POCMainViewController : UIViewController <POCFlipsideViewControllerDelegate, UIScrollViewDelegate>

    @property (nonatomic,retain) IBOutlet UIScrollView *scroller;
    @end

这是我的.m文件

#import "POCMainViewController.h"

@interface POCMainViewController ()

@end

@implementation POCMainViewController


@synthesize scroller =_scroller;

- (void)viewDidAppear:(BOOL)animated
{

     [_scroller setContentSize:CGSizeMake(80.0f, 320.0f)];
     [_scroller setFrame:CGRectMake(120, 131, 80, 214)];

    [super viewDidAppear:animated];
}

- (void)viewDidLoad
{
    _scroller.delegate = self;
    _scroller.showsVerticalScrollIndicator = NO;
    _scroller.decelerationRate = UIScrollViewDecelerationRateFast;

    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - Flipside View

- (void)flipsideViewControllerDidFinish:(POCFlipsideViewController *)controller
{
    [self dismissViewControllerAnimated:YES completion:nil];
}

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([[segue identifier] isEqualToString:@"showAlternate"]) {
        [[segue destinationViewController] setDelegate:self];
    }
}

@end

其余部分是直接来自 Xcode 的样板。

Answer 1

我发现 UIScrollView 的罪魁祸首通常是自动布局。在 Storyboard 中，突出显示主视图 Controller 下的 View 元素，然后在右侧栏中打开“显示文件检查器”窗口。在“Interface Builder 文档”下，取消选择“使用自动布局”，看看是否能解决您的问题。