我正在为iPhone编写Objective-C程序.
我正在尝试实现UILongPressGestureRecognizer,并且无法让它按照我想要的方式运行.
我想做的很简单：
回应屏幕上按下的触摸.
无论何时触摸移动和触摸开始,UILongPressGestureRecognizer都能正常工作,但如果我在同一个地方按住触摸,则没有任何反应.
为什么？
我怎样才能处理触摸开始,而不是移动,并保持在完全相同的位置？
这是我目前的代码.
// Configure the press and hold gesture recognizer touchAndHoldRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(touchAndHold:)]; touchAndHoldRecognizer.minimumPressDuration = 0.1; touchAndHoldRecognizer.allowableMovement = 600; [self.view addGestureRecognizer:touchAndHoldRecognizer];
解决方法
您描述的行为,即手动识别器在您不移动时不会再接收到处理程序的调用,这是标准行为.移动时这些手势的状态属性是UIGestureRecognizerStateChanged类型,因此如果事情没有改变,则不会调用您的处理程序.
你可以
>在调用UIGestureRecognizerStateBegan状态的手势识别器时,启动重复计时器;
>在调用状态为UIGestureRecognizerStateCancelled,UIGestureRecognizerStateFailed或UIGestureRecognizerStateEnded的手势识别器时,然后使计时器无效并释放;
>确保手势识别器方法在某些类属性中保存您正在查找的任何值(例如,locationInView的值或其他)
所以,可能是这样的：
@interface ViewController ()
@property (nonatomic) CGPoint location;
@property (nonatomic,strong) NSTimer *timer;
@end
@implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
UILongPressGestureRecognizer *gesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleGesture:)];
gesture.minimumPressDuration = 0.1;
gesture.allowableMovement = 600;
[self.view addGestureRecognizer:gesture];
}
- (void)handleTimer:(NSTimer *)timer
{
[self someMethod:self.location];
}
- (void)handleGesture:(UIGestureRecognizer *)gesture
{
self.location = [gesture locationInView:self.view];
if (gesture.state == UIGestureRecognizerStateBegan)
{
self.timer = [NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(handleTimer:) userInfo:nil repeats:YES];
}
else if (gesture.state == UIGestureRecognizerStateCancelled ||
gesture.state == UIGestureRecognizerStateFailed ||
gesture.state == UIGestureRecognizerStateEnded)
{
[self.timer invalidate];
self.timer = nil;
}
[self someMethod:self.location];
}
- (void)someMethod:(CGPoint)location
{
// move whatever you wanted to do in the gesture handler here.
NSLog(@"%s",__FUNCTION__);
}
@end
