對UILongPressGestureRecognizer的持續時間執行操作

Question

我想改變的值UISlider而連續UIButton有UILongPressGestureRecognizer正在舉行連接到它。 現在我只是在觸地和觸摸（開始/結束）時調用我的UILongPressGestureRecognizer委托。

我是否可以在不占用UI的情況下執行UIGestureRecognizerStateBegan到UIGestureRecognizerStateEnded的操作？ 正如所料，使用while()循環不起作用。

Answer 1

這是一個如何實現您正在尋找的工作示例。 我測試了它，效果很好。

所有這些代碼都在* .m文件中。 這是一個非常簡單的類，只是擴展了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

希望這可以幫助！