我正在尝试使用启用分页的 UIScrollView。我将各种 UIView 作为子视图添加到 UISCrollView。我希望这些子视图小于滚动视图的大小,所以我相应地修改了我的约束。现在,当我实际向左/向右滑动它们时,它们恰好不在中心。我期待它以当前页面为中心显示从侧面窥视的上一个/下一个视图。
下面是我的代码滚动视图实现
//
// ViewController.m
// Paging
//
#import "ViewController.h"
@interface ViewController ()
@property (nonatomic, strong) UIScrollView *pagingScrollView;
@end
@implementation ViewController
- (UIScrollView *)pagingScrollView {
if (!_pagingScrollView) {
_pagingScrollView = [[UIScrollView alloc] initWithFrame:CGRectZero];
_pagingScrollView.translatesAutoresizingMaskIntoConstraints = NO;
_pagingScrollView.backgroundColor = [UIColor orangeColor];
_pagingScrollView.showsHorizontalScrollIndicator = NO;
_pagingScrollView.showsVerticalScrollIndicator = NO;
_pagingScrollView.contentInset = UIEdgeInsetsZero;
_pagingScrollView.pagingEnabled = YES;
_pagingScrollView.clipsToBounds = NO;
_pagingScrollView.bounces = NO;
}
return _pagingScrollView;
}
- (void)viewDidLoad {
[super viewDidLoad];
[self scrollViewSetUp];
NSDictionary *views = NSDictionaryOfVariableBindings(_pagingScrollView);
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[_pagingScrollView]|"
options:0
metrics:nil
views:views]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[_pagingScrollView]|"
options:0
metrics:nil
views:views]];
}
- (void)scrollViewSetUp {
[self.view addSubview:self.pagingScrollView];
UIView *lastView = nil;
NSInteger arrayCount = 5;
for(NSInteger index = 0; index < arrayCount; index++)
{
UIView *view = [[UIView alloc] initWithFrame:CGRectZero];
view.translatesAutoresizingMaskIntoConstraints = NO;
view.backgroundColor = [UIColor yellowColor];
[self.pagingScrollView addSubview:view];
[self.pagingScrollView addConstraint:[NSLayoutConstraint constraintWithItem:view
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:self.pagingScrollView
attribute:NSLayoutAttributeTop
multiplier:1
constant:40]];
[self.pagingScrollView addConstraint:[NSLayoutConstraint constraintWithItem:view
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:self.pagingScrollView
attribute:NSLayoutAttributeHeight
multiplier:0.80
constant:0]];
[self.pagingScrollView addConstraint:[NSLayoutConstraint constraintWithItem:view
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:self.pagingScrollView
attribute:NSLayoutAttributeWidth
multiplier:0.80
constant:0]];
if (lastView == nil && index == 0){
[self.pagingScrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-20-[view(==_pagingScrollView)]"
options:0
metrics:nil
views:@{@"view":view, @"_pagingScrollView":_pagingScrollView}]];
} else {
[self.pagingScrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[lastView]-20-[view]"
options:0
metrics:nil
views:@{@"lastView":lastView, @"view":view, @"_pagingScrollView":_pagingScrollView}]];
}
if(index == arrayCount-1) {
[self.pagingScrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:[view]-20-|"
options:0
metrics:nil
views:@{@"view":view}]];
}
lastView = view;
}
}
@end
任何指针/评论/反馈高度赞赏。谢谢。