ios - Objective-C - 在验证数据时使用 subview 阻止触摸或手势

Question

我想要一个 UIView 来阻止响应手势的 subview 。主要目的是在服务器中验证数据时阻止用户界面的触摸和手势。处理请求后，它将从顶部移除阻塞 UIView。

如何做到这一点？到目前为止，我有以下内容:

@interface TableViewController ()
    @property (weak, nonatomic) IBOutlet UITableView *table;
    @property (strong, nonatomic) IBOutlet UIView *blockingScreen;
    ....
@end

实现:

@implementation PlayListViewController

    - (void)viewDidLoad
    {
        [super viewDidLoad];
        _table.dataSource      = self;
        _table.delegate        = self;

        // Blocking screen should take all the screen. 
        // Unfortunately, when it is displayed it gets the table size , ??
        _blockingScreen = [[UIView alloc] initWithFrame:CGRectMake(0,0,
                                         [[UIScreen mainScreen] applicationFrame].size.width,
                                         [[UIScreen mainScreen], applicationFrame].size.height)];

        _blockingScreen.userInteractionEnabled = NO;

        [self loadGestureRecognizer];
    }

    - (void) loadGestureRecognizer
    {
        // Long press gesture recognizer declaration
        UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressGestureRecognized:)];

        // Swipe gesture recognizer declaration
        UISwipeGestureRecognizer *swipeLeftGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipeGestureRecognizer:)];
        swipeLeftGesture.direction = UISwipeGestureRecognizerDirectionLeft;

        // Attach gesture recognizers
        [_songsTable addGestureRecognizer:longPress];
        [_songsTable addGestureRecognizer:swipeLeftGesture];
    }

    // At some point, the gesture recognizer will be invoked
    // In this case when swiping a table row
    - (IBAction)swipeGestureRecognizer:(UISwipeGestureRecognizer *)sender 
    {
        // Do things
        ...

       // Preparing for doing Http request
       // I want to display the blockingScreen on top of all views
       // so no gestures are recognized.
       [_table addSubview:_blockingScreen];
       [_blockingScreen setBackgroundColor:[UIColor blackColor]];
       _blockingScreen.alpha = 0.3;

       // Bring to front
       [_table bringSubviewToFront:_blockingScreen];

       // To avoid gesture recognition I'm forced to do the following
       _table.userInteractionEnabled = NO;
    }
@end

在某些时候，滑动手势将调用 swipeGestureRecognizer。那很好用。 blockingScreen 似乎位于表格 View 的顶部(仅视为表格)并且不会阻止任何手势。

我是 objective-c 和 xcode 的新手，所以欢迎提供解释、教程或外部资源。我已经在 SO 中阅读了一些其他答案，例如 How to disable touch input to all views except the top-most view? , Container View Receives Touches Instead of Subview on iPad并尝试:

_blockingScreen.userInteractionEnabled = NO;

也为了

_blockingScreen.userInteractionEnabled = YES; 

并没有发现任何区别。

有人知道吗？

Answer 1

这可以通过在执行处理时忽略交互事件来更容易地完成。

[[UIApplication sharedApplication] beginIgnoringInteractionEvents];

// Do all the things

[[UIApplication sharedApplication] endIgnoringInteractionEvents];

更多信息在 documentation .