问题描述
iOS7 &iOS8
iOS7 & iOS8
我需要在 UIScrollview 中禁用两指或三指滚动.
I need to disable 2 or three fingers scrolling in UIScrollview.
我试过了:
[self.scrollView.panGestureRecognizer setMaximumNumberOfTouches:1];
[self.scrollView.panGestureRecognizer setMinimumNumberOfTouches:1];
但它没有效果.仍然可以用两根手指滚动.
But it has no effect. It is still possible to scroll with 2 fingers.
如果我尝试将 max 和 min 设置为 2.一个手指滚动被禁用但 3 个手指滚动可能:(
If i tried to set max and min to 2. One finger scrolling was disabled but 3 fingers scrolling possible :(
我也试过了，但没有成功:
I tried this too, but without success:
for (UIGestureRecognizer* pan in self.scrollView.gestureRecognizers) {
OTTNSLog(@"touches: %ld", (unsigned long)pan.numberOfTouches);
if ([pan isKindOfClass:[UIPanGestureRecognizer class]])
{
UIPanGestureRecognizer *mpanGR = (UIPanGestureRecognizer *) pan;
mpanGR.minimumNumberOfTouches = 1;
mpanGR.maximumNumberOfTouches = 1;
}
if ([pan isKindOfClass:[UISwipeGestureRecognizer class]])
{
UISwipeGestureRecognizer *mswipeGR = (UISwipeGestureRecognizer *) pan;
mswipeGR.numberOfTouchesRequired = 1;
}
}
有人知道，它是如何解决这个问题的吗?
Does anybody know, how it solve this ?
谢谢.
推荐答案
问题:
当 UIPanGestureRecognizer 是 UIScrollView 的底层时 - 不幸的是，这也会影响 UIPageViewController - maximumNumberOfTouches 未按预期运行，minimumNumberOfTouches 但是总是正确地限制下限.
When the UIPanGestureRecognizer is underlying a UIScrollView - which unfortunately does also effect UIPageViewController - the maximumNumberOfTouches is not behaving as expected, the minimumNumberOfTouches however always limits the lower end correctly.
在监控这些参数时，它们会报告正确的值——它们似乎在做自己的工作——只是 UIScrollView 本身不尊重它们并忽略它们的设置！
When monitoring these parameters they report back correct values - they seem to do their job - it's just that UIScrollView itself doesn't honor them and ignores their settings!
解决方案:
将 minimumNumberOfTouches 设置为所需的值，例如1 和 - 非常重要 - maximumNumberOfTouches 到 2 !!!
Set the minimumNumberOfTouches to the desired value e.g. 1 and - very importantly - the maximumNumberOfTouches to 2 !!!
myScrollView.panGestureRecognizer.minimumNumberOfTouches = 1;
myScrollView.panGestureRecognizer.maximumNumberOfTouches = 2;
在滚动视图的@interface 声明中符合 UIGestureRecognizerDelegate 协议.您不必为 UIScrollView 设置 panGestureRecognizer.delegate ！！！委托已经设置，因为 UIScrollView 需要是它自己的 pan/pinchGestureRecognizer 的委托.
Conform to the UIGestureRecognizerDelegate protocol in your scrollView's @interface declaration. You don't have to set the panGestureRecognizer.delegate for a UIScrollView!!! The delegate is already set because UIScrollView requires to be the delegate of its own pan/pinchGestureRecognizer.
然后实现UIGestureRecognizer委托方法:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
NSLog(@"%d", gestureRecognizer.numberOfTouches);
NSLog(@"%@", gestureRecognizer.description);
if (gestureRecognizer == self.panGestureRecognizer) {
if (gestureRecognizer.numberOfTouches > 1) {
return NO;
} else {
return YES;
}
} else {
return YES;
}
}
}
<小时>
更安全的版本:
如果您有一个自定义的 scrollView 类并且想要非常安全，您还可以再添加一行代码来消除与其他 scrollView 的歧义:
If you have a custom scrollView class and wanna be on the VERY safe side you can also add one more line of code to disambiguate against other scrollViews:
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
NSLog(@"%d", gestureRecognizer.numberOfTouches);
NSLog(@"%@", gestureRecognizer.description);
if ([gestureRecognizer.view isMemberOfClass:[MY_CustomcrollView class]]) {
if (gestureRecognizer == self.panGestureRecognizer) {
if (gestureRecognizer.numberOfTouches > 1) {
return NO;
} else {
return YES;
}
} else {
return YES;
}
} else {
return YES;
}
}
<小时>
附加信息:
NSLog 告诉您触摸的次数.如果您将 min 和 max 设置为相同的值(如上例中的 1)，if-loop 永远不会被触发... ;-)
The NSLogs tell you the number of touches. If you set both the min and max to the same value (like 1 in the example above) the if-loop would never be triggered... ;-)
这就是为什么 maximumNumberOfTouches 必须至少为 minimumNumberOfTouches + 1
That is why maximumNumberOfTouches has to be at least minimumNumberOfTouches + 1
panGestureRecognizer.minimumNumberOfTouches = 1;
panGestureRecognizer.maximumNumberOfTouches = minimumNumberOfTouches + 1;
<小时>
极客部分:
for (UIView *view in self.view.subviews) {
if ([view isKindOfClass:[UIScrollView class]]) {
NSLog(@"myPageViewController - SCROLLVIEW GESTURE RECOGNIZERS: %@", view.gestureRecognizers.description);
((UIPanGestureRecognizer *)view.gestureRecognizers[1]).minimumNumberOfTouches = 1;
((UIPanGestureRecognizer *)view.gestureRecognizers[1]).maximumNumberOfTouches = 2;
}
}
这是访问负责 UIPageViewController 分页的底层滚动视图的方法.将此代码放在例如UIPageViewController(自身)的viewDidLoad:.
如果您根本无法访问滚动视图 - 就像动态 UITableViewCell 中的 UIPageViewController 在运行时发生创建和单元重用并且没有插座可以在其 contentViews 上设置 - 在 UIScrollView 上放置一个类别并在那里覆盖委托方法.不过要小心！这会影响您的应用程序中的每个滚动视图 - 所以要像上面的更安全"示例中那样进行适当的自省(类检查)...... ;-)
If you don't have access to the scrollView at all - like for a UIPageViewController in a dynamic UITableViewCell where creation and cell reuse happens at runtime and no outlets can be set on its contentViews - put a category on UIScrollView and override the delegate method there. But be careful! This effects every scrollView in your application - so do proper introspection (class-checking) like in my 'EVEN SAFER' example above... ;-)
旁注:
不幸的是，同样的技巧不适用于 UIScrollView 上的 pinchGestureRecognizer 因为它不公开 min/maxNumberOfTouches 属性.当被监控时，它总是报告 2 次触摸(你显然需要捏) - 所以它的内部 min/maxNumberOfTouches 似乎都设置为2 - 即使 UIScrollView 不遵守其自己的设置并继续愉快地用任意数量的手指(超过 2 个)捏合.所以没有办法将捏合限制在有限数量的手指上......
Unfortunately the same trick doesn't work with the pinchGestureRecognizer on UIScrollView because it doesn't expose a min/maxNumberOfTouches property. When monitored it always reports 2 touches (which you obviously need to pinch) - so its internal min/maxNumberOfTouches seem to have been set both to 2 - even if UIScrollView isn't honoring its own settings and keeps happily pinching with any numbers of fingers (more than 2). So there is no way to restrict pinching to a limited amount of fingers...
这篇关于UIScrollView 只能用一根手指滚动的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！