Question

我想要在UISlider附加UIButton的情况下连续更改UILongPressGestureRecognizer的值。现在，我只接到我的UILongPressGestureRecognizer代表的电话，然后触摸起来（开始/结束）。

我是否可以在不占用用户界面的情况下从UIGestureRecognizerStateBegan执行操作UIGestureRecognizerStateEnded？正如所料，使用while()循环不起作用。

Answer 1

以下是如何完成您所需要的工作示例。我测试了它，效果很好。

所有这些代码都在* .m文件中。这是一个非常简单的类，只是扩展UIViewController。

#import "TSViewController.h"

@interface TSViewController ()

@property (nonatomic, strong) NSTimer *longPressTimer;

@end

@implementation TSViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressGesture:)];
    [self.view addGestureRecognizer:longPress];
}

-(void)longPressGesture:(UILongPressGestureRecognizer*)longPress {

    // The long press gesture recognizer has been, well, recognized
    if (longPress.state == UIGestureRecognizerStateBegan) {

        if (self.longPressTimer) {
            [self.longPressTimer invalidate];
            self.longPressTimer = nil;
        }

        // Here you can fine-tune how often the timer will be fired. Right
        // now it's been fired every 0.5 seconds
        self.longPressTimer = [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(longPressTimer:) userInfo:nil repeats:YES];
    }

    // Since a long press gesture is continuous you have to detect when it has ended
    // or when it has been cancelled
    if (longPress.state == UIGestureRecognizerStateEnded || longPress.state == UIGestureRecognizerStateCancelled) {
        [self.longPressTimer invalidate];
        self.longPressTimer = nil;
    }
}

-(void)longPressTimer:(NSTimer*)timer {

    NSLog(@"User is long-pressing");
}

@end

希望这有帮助！

对UILongPressGestureRecognizer的持续时间执行操作

1 个答案: