Iphone NaN回答说,正在尝试接触点
好吧,我(对我来说)遇到了一个非常奇怪的问题。我的视图中有一个150x150按钮,我在该按钮上添加了一个Iphone NaN回答说,正在尝试接触点,iphone,objective-c,location,touch,uigesturerecognizer,Iphone,Objective C,Location,Touch,Uigesturerecognizer,好吧,我(对我来说)遇到了一个非常奇怪的问题。我的视图中有一个150x150按钮,我在该按钮上添加了一个ui长按手势识别器,因为我需要知道按下按钮时按钮被按下的位置。我的代码如下所示: -(CGPoint)detectedTouch:(UILongPressGestureRecognizer *)sender { CGPoint touchPoint = [sender locationInView:button]; return touchPoint; } -(void
ui长按手势识别器
,因为我需要知道按下按钮时按钮被按下的位置。我的代码如下所示:
-(CGPoint)detectedTouch:(UILongPressGestureRecognizer *)sender {
CGPoint touchPoint = [sender locationInView:button];
return touchPoint;
}
-(void)myAction {
CGPoint touchPoint = [self detectedTouch:myGestureRecognizer];
NSLog(@"touchPoint = %f, %f", touchPoint.x, touchPoint.y);
//do stuff
}
switch (sender.state){
case UIGestureRecognizerStatePossible:
NSLog(@"possible");
break;
case UIGestureRecognizerStateFailed:
NSLog(@"Failed!");
break;
... All Cases wanted
default:
break;
}
现在,当按钮处于正常视图时,一切正常。但是,当按钮位于滚动视图上时,它只在按下按钮约一秒钟后才起作用。如果你释放得太快,日志会告诉我:
touchPoint = nan, nan
如果您能帮助解决此问题,我们将不胜感激
UIgestureRecognitor
在其生命周期中具有各种状态,例如可能、已识别、已失败、已结束和已取消。我会尝试在状态的识别器方法中放入一个switch语句,看看哪个语句可以更好地缩小问题的范围。它看起来像这样:
-(CGPoint)detectedTouch:(UILongPressGestureRecognizer *)sender {
CGPoint touchPoint = [sender locationInView:button];
return touchPoint;
}
-(void)myAction {
CGPoint touchPoint = [self detectedTouch:myGestureRecognizer];
NSLog(@"touchPoint = %f, %f", touchPoint.x, touchPoint.y);
//do stuff
}
switch (sender.state){
case UIGestureRecognizerStatePossible:
NSLog(@"possible");
break;
case UIGestureRecognizerStateFailed:
NSLog(@"Failed!");
break;
... All Cases wanted
default:
break;
}
我不知道内部细节,但如果失败/取消,它可能不会在视图中选择位置
下面是关于手势识别器子类化的文档以及可能发生的状态
我试图重现您的问题,但没有成功。起初,我认为手势识别器可能会干扰scrollView滚动手势识别器,但事实似乎并非如此。以下是我的代码:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
UILongPressGestureRecognizer *recognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongHold:)];
// [scrollView addGestureRecognizer:recognizer];
UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 100, 2000)];
lbl.text = @"lorem ipsum......";
lbl.numberOfLines = 0;
scrollView.contentSize = CGSizeMake(lbl.frame.size.width, lbl.frame.size.height);
[scrollView addSubview:lbl];
btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = CGRectMake(0, 0, 150, 150);
[btn addGestureRecognizer:recognizer];
[scrollView addSubview:btn];
v = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];
v.backgroundColor = [UIColor yellowColor];
v.hidden = YES;
[scrollView addSubview:v];
}
- (void) handleLongHold:(UILongPressGestureRecognizer*) recognizer {
NSLog(@"long tap handled");
v.hidden = NO;
v.center = [recognizer locationInView:btn];
}
顺便说一句,我无意中发现了您的问题,正在寻找一种从手势识别器选择器中找到接触点的方法-locationInView方法帮助了我,希望这段代码能帮助您。好的,谢谢,但不知怎的,我的问题与scrollView有关。获取触摸点的目的是以不同的方式设置按钮的动画,具体取决于您触摸按钮的位置。为了测试,我移除了我检查触摸位置的部分,并在按下按钮时使其沿y轴向下移动,在不再按下按钮时将其移回原始位置。在常规视图中,它按预期工作,但在滚动视图中,它仅在延迟后工作(如上所述),并且动画不是流体。有什么想法吗?