如何使用两个单独的 UIBarButtonItem 禁用/启用 UIPanGestureRecognizer？

Posted 2023-03-16

【中文标题】如何使用两个单独的 UIBarButtonItem 禁用/启用 UIPanGestureRecognizer？

【英文标题】：How to disable/enable a UIPanGestureRecognizer with two separate UIBarButtonItems?

【发布时间】：2015-11-09 05:19:36

【问题描述】：

我正在尝试通过单击“保存”按钮关闭UIPanGestureRecognizer。然后，我试图通过单击“编辑”按钮重新打开这个UIPanGestureRecognizer。我可以用下面的代码弄清楚如何关闭它们：

- (IBAction)saveButton:(id)sender 

buttonCount ++;
if (buttonCount > 0) 

    for (_buttonField in self.view.subviews) 
        _buttonField.gestureRecognizers = nil;

        _buttonField.layer.borderColor = [UIColor blackColor].CGColor;


    
    
    

然而，我有两个问题。首先，这是关闭所有手势识别器，我不想这样做。其次，我不知道如何重新打开它们。为此，我尝试了以下方法：

- (IBAction)editButton:(id)sender 

buttonCount ++;
if (buttonCount > 0) 

    if ([[UIColor colorWithCGColor:_buttonField.layer.borderColor] isEqual:[UIColor whiteColor]]) 

    for (_buttonField in self.view.subviews) 
        _buttonField.gestureRecognizers = YES;

    

但是，我在设置为 YES 的代码行上收到错误。

这是我的完整代码集供参考：

@implementation FieldGoalChartViewController





-(void)viewDidLoad
[super viewDidLoad];








- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(nullable UIEvent *)event 
UITouch *aTouch = [touches anyObject];

CGRect buttonRect = self.buttonField.frame;


CGPoint point = [aTouch locationInView:self.buttonField.superview];



if (!CGRectContainsPoint(buttonRect, point)) 
        _buttonField.layer.borderColor = [UIColor blackColor].CGColor;
        _draggedView.layer.borderColor = [UIColor blackColor].CGColor;
    for (_buttonField in self.view.subviews) 
        _buttonField.layer.borderColor = [UIColor blackColor].CGColor;

    

    


    

- (void)longPress:(UILongPressGestureRecognizer*)gesture 
if ( gesture.state == UIGestureRecognizerStateBegan ) 
    gesture.view.layer.borderColor = [UIColor whiteColor].CGColor;


    UIAlertController * alert=   [UIAlertController
                                  alertControllerWithTitle:@"Would you like to delete the selected rep(s)?"
                                  message:nil
                                  preferredStyle:UIAlertControllerStyleAlert];

    UIAlertAction* deleteButton = [UIAlertAction
                                actionWithTitle:@"Delete"
                                style:UIAlertActionStyleDefault
                                handler:^(UIAlertAction * action)

                                   
                                       for (_buttonField in self.view.subviews) 
                                           if ([[UIColor colorWithCGColor:_buttonField.layer.borderColor] isEqual:[UIColor whiteColor]]) 

                                               [_buttonField removeFromSuperview];

                                           
                                       

                                    [alert dismissViewControllerAnimated:YES completion:nil];

                                ];
    UIAlertAction* cancelButton = [UIAlertAction
                               actionWithTitle:@"Cancel"
                               style:UIAlertActionStyleDefault
                               handler:^(UIAlertAction * action)
                                   






                                   [alert dismissViewControllerAnimated:YES completion:nil];

                               ];

    [alert addAction:deleteButton];
    [alert addAction:cancelButton];

    [self presentViewController:alert animated:YES completion:nil];
    
    




    - (void)panWasRecognized:(UIPanGestureRecognizer *)panner 

    

    panner.view.layer.borderColor = [UIColor whiteColor].CGColor;


   _draggedView = panner.view;

    CGPoint offset = [panner translationInView:_draggedView.superview];
    CGPoint center = _draggedView.center;
    _draggedView.center = CGPointMake(center.x + offset.x, center.y + offset.y);
    _draggedView.layer.masksToBounds =YES;
    _buttonField.layer.borderWidth = 3.0f;




    // Reset translation to zero so on the next `panWasRecognized:` message, the
    // translation will just be the additional movement of the touch since now.
    [panner setTranslation:CGPointZero inView:_draggedView.superview];

    

    



-(void)buttonTouched:(UIButton*)sender forEvent:(id)tap 
NSSet *touches = [tap allTouches];
UITouch *touch = [touches anyObject];
UITouchPhase *phase = touch.phase;
touch.view.layer.borderColor = [UIColor whiteColor
                                ].CGColor;



-(void)doubleTapped:(UIButton*)sender forEvent:(id)twoTaps 
NSSet *touches = [twoTaps allTouches];
UITouch *touch = [touches anyObject];
UITouchPhase *phase = touch.phase;
touch.view.layer.borderColor = [UIColor blackColor].CGColor;


- (IBAction)saveButton:(id)sender 

buttonCount ++;
if (buttonCount > 0) 

    for (_buttonField in self.view.subviews) 
        _buttonField.gestureRecognizers = nil;

        _buttonField.layer.borderColor = [UIColor blackColor].CGColor;


    
    
  

- (IBAction)editButton:(id)sender 

buttonCount ++;
if (buttonCount > 0) 

    if ([[UIColor colorWithCGColor:_buttonField.layer.borderColor] isEqual:[UIColor whiteColor]]) 

    for (_buttonField in self.view.subviews) 
        _buttonField.gestureRecognizers = YES;

    





- (IBAction)addRepButton:(UIBarButtonItem *)newRep 

self.labelCounter++;

buttonCount ++;
if (buttonCount > 0 )


    _buttonField = [[UIButton alloc]initWithFrame:CGRectMake(300, 300, 28, 28)];
    [_buttonField setTitle:[NSString stringWithFormat:@"%i", self.labelCounter]forState:UIControlStateNormal];
    [_buttonField setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
    _buttonField.contentHorizontalAlignment = UIControlContentHorizontalAlignmentCenter;
    _buttonField.userInteractionEnabled = YES;
    _buttonField.layer.cornerRadius = 14;
    _buttonField.layer.borderColor = [UIColor blackColor].CGColor;
    _buttonField.layer.borderWidth = 3.0f;
    _buttonField.titleLabel.font = [UIFont boldSystemFontOfSize:13];
    [_buttonField setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    _buttonField.layer.backgroundColor = [UIColor blackColor].CGColor;
    _buttonField.layer.masksToBounds = YES;

    //Pan gesture declared in button
    UIPanGestureRecognizer *panner = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panWasRecognized:)];
    [_buttonField addGestureRecognizer:panner];

    //Long Press gesture declared in button
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];
    [self.buttonField addGestureRecognizer:longPress];

    //Touch down inside declared in button
    [self.buttonField addTarget:self action:@selector(buttonTouched:forEvent:) forControlEvents:UIControlEventTouchDown];

    //Double Tap inside declared in button
    [self.buttonField addTarget:self action:@selector(doubleTapped:forEvent:) forControlEvents:UIControlEventTouchDownRepeat];

    [self.view addSubview:(_buttonField)];















@end

我想知道如何通过点击我的“保存”UIBarButton 来专门关闭UIPanGestureRecognizer，然后通过点击我的“编辑”UIBarButton 来关闭UIPanGestureRecognizer。

【问题讨论】：

您可以启用/禁用 PanGestureRecognizer，只需将其启用属性设置为 YES 或 NO。

如果m文件中设置了手势可以这样做吗

是的。 “启用”只是每个手势识别器的一个属性，参见 developer.apple.com/library/ios/documentation/UIKit/Reference/…>。

这是我用来禁用平移手势属性的代码- (IBAction)saveButton:(id)sender buttonCount ++; if (buttonCount > 0) for (_buttonField in self.view.subviews) UIPanGestureRecognizer *panner = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panWasRecognized:)]; panner.enabled = NO;

知道为什么这没有触发吗？

【参考方案1】：

如果您在 IB 中添加了 Pan 手势，那么您可以创建 outlet 并使用手势实例上的 enabled 属性来启用和禁用手势，很简单。

panGestureRecognizer.enabled = NO; (or)
panGestureRecognizer.enabled = YES;

【讨论】：

这确实有道理，但是当我将手势添加到按钮并将其称为禁用时，它在模拟器中不起作用。

我试图通过在 .h 中声明它来解决这个问题，但我无法弄清楚