我一直在寻找一种禁用垂直反弹的方法,以获取uiscrollview,但仅在底部。我仍然需要在顶部弹跳。
找不到任何东西。这可能吗?
预先感谢!
使用uiscrollviewDelegate方法scrollViewDidScroll
检查滚动浏览的内容偏移,并或更少检查用户是否试图超越滚动视图的底端。然后,只需使用它将滚动返回到滚动视图的末端即可。它发生得如此迅速,以至于您甚至无法说出滚动视图完全弹跳或延伸超出其范围。
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (scrollView.contentOffset.y >= scrollView.contentSize.height - scrollView.frame.size.height) {
[scrollView setContentOffset:CGPointMake(scrollView.contentOffset.x, scrollView.contentSize.height - scrollView.frame.size.height)];
}
}
在swift中禁用垂直反弹:
func scrollViewDidScroll(scrollView: UIScrollView) {
if scrollView.contentOffset.y < 0 {
scrollView.contentOffset.y = 0
}
}
在Swift中禁用垂直反弹:
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.contentOffset.y > scrollView.contentSize.height - scrollView.bounds.height {
scrollView.contentOffset.y = scrollView.contentSize.height - scrollView.bounds.height
}
}
基于0x7fffffff的答案,我创建了一个类:
verticalbouncecontrol.h
#import <UIKit/UIKit.h>
@interface VerticalBounceControl : NSObject
@property (nonatomic, assign) BOOL bounce;
- (id) initWithScrollView:(UIScrollView*)scrollView bounceAtTop:(BOOL)bounceAtTop bounceAtBottom:(BOOL)bounceAtBottom;
@end
verticalbouncecontrol.m
#import "VerticalBounceControl.h"
@interface VerticalBounceControl ()
@property (nonatomic, retain) UIScrollView* scrollView;
@property (nonatomic, assign) BOOL bounceAtTop;
@property (nonatomic, assign) BOOL bounceAtBottom;
@end
@implementation VerticalBounceControl
- (id) initWithScrollView:(UIScrollView*)scrollView bounceAtTop:(BOOL)bounceAtTop bounceAtBottom:(BOOL)bounceAtBottom {
self = [super init];
if(self) {
self.bounce = YES;
self.scrollView = scrollView;
self.bounceAtTop = bounceAtTop;
self.bounceAtBottom = bounceAtBottom;
[self.scrollView addObserver:self forKeyPath:@"contentOffset" options:NSKeyValueObservingOptionNew context:NULL];
}
return self;
}
- (void) dealloc {
[self.scrollView removeObserver:self forKeyPath:@"contentOffset"];
self.scrollView = nil;
}
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
if ([keyPath isEqualToString:@"contentOffset"]) {
if (self.bounce && ((self.scrollView.contentOffset.y<=0 && self.bounceAtTop) || (self.scrollView.contentOffset.y>=self.scrollView.contentSize.height-1 && self.bounceAtBottom))) {
self.scrollView.bounces = YES;
} else {
self.scrollView.bounces = NO;
}
}
}
@end
可以使用呼叫者是UIScrollView
的代表,可以使用:
VerticalBounceControl* bounceControl = [[VerticalBounceControl alloc] initWithScrollView:anyScrollView bounceAtTop:YES bounceAtBottom:NO];
这样,您可以为您不想更改其委托的UIScrollView
S具有这种反弹行为(例如UIWebView
的一个)。
再次,谢谢 @0x7ffffffff解决方案!
swift 3:
这仅在底部禁用垂直反弹:
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.contentOffset.y > scrollView.contentSize.height - scrollView.bounds.height {
scrollView.contentOffset.y = scrollView.contentSize.height - scrollView.bounds.height
}
}
当滚动到底部时,让我们禁用bounces
。
scrollView.bounces = scrollView.contentOffset.y < scrollView.contentSize.height - scrollView.frame.height
我将fabsf()
添加到0x7fffffff♦的解决方案也可以满足负(向下)滚动:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (fabsf(scrollView.contentOffset.y) >= scrollView.contentSize.height - scrollView.frame.size.height) {
[scrollView setContentOffset:CGPointMake(scrollView.contentOffset.x, scrollView.contentSize.height - scrollView.frame.size.height)];
}
}
我一直在寻找一种解决方案,以使底部弹跳仅用于比设备更宽的滚动浏览,因为我使用的是分页。这些都不适合我,但我找到了一种方法。我以为我应该分享这一点,因为我浪费了两天才能做到这一点。我正在使用Swift 4,但是如果您知道如何转换它,则适用于目标C,如果您有两者都有经验,那应该很容易。
这在带有设备屏幕框架的滚动浏览中起作用。
-
添加变量以了解Scrollview的当前页面。
var currentPage : Int!
-
设置初始值
currentPage = 0
-
滚动后更新
currentPage
public func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) { let width = scrollView.frame.size.width let page = (scrollView.contentOffset.x + (0.5 * width)) / width currentPage = Int(page) }
-
过滤底部滚动和更新contentoffset
public func scrollViewDidScroll(_ scrollView: UIScrollView) { if CGFloat(currentPage) * screenWidth < scrollView.contentOffset.x || CGFloat(currentPage) * screenWidth < scrollView.contentOffset.y || (((CGFloat(currentPage) * screenWidth - scrollView.contentOffset.x) >= 0) && scrollView.contentOffset.y > 0){ scrollView.contentOffset.y = 0 } }
CGFloat(currentPage) * screenWidth < scrollView.contentOffset.x || CGFloat(currentPage) * screenWidth < scrollView.contentOffset.y
将过滤左下和右下角
(((CGFloat(currentPage) * screenWidth - scrollView.contentOffset.x) >= 0) && scrollView.contentOffset.y > 0)
将过滤底部滚动
scrollView.contentOffset.y = 0
将阻止其滚动