固定UIScrollView滑动的方向

固定UIScrollView滑动的方向

一般而言,我们通过这两个参数CGRectMake以及contentSize就可以自动的让UIScrollView只往一个方向滚动.但我遇到过非常奇葩的情况,那就是即使设置的CGRectMake以及contentSize没有一点点问题,这个UIScrollView也能够上下左右滚动-_-!!.

为了不依赖于CGRectMake以及contentSize,我们可以通过在代理方法scrollViewDidScroll:中进行限制即可.

没有限制之前的效果:

源码:

//

// RootViewController.m

// BUG

// Copyright (c) 2014年 Y.X. All rights reserved.

#import "RootViewController.h"

@interface RootViewController () UIScrollViewDelegate 

 UIScrollView *_showView;

@implementation RootViewController

- (void)viewDidLoad

 [super viewDidLoad];

 UIImageView *showImageView = \

 [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"长图.jpg"]];

 _showView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 50, 320, 100)];

 _showView.delegate = self;

 [_showView addSubview:showImageView];

 _showView.contentSize = showImageView.frame.size;

 [self.view addSubview:_showView];

- (void)scrollViewDidScroll:(UIScrollView *)scrollView

 CGPoint point = scrollView.contentOffset;

// point.y = 0.f;

 scrollView.contentOffset = point;

@end

限制后效果:

//

// RootViewController.m

// BUG

// Copyright (c) 2014年 Y.X. All rights reserved.

#import "RootViewController.h"

@interface RootViewController () UIScrollViewDelegate 

 UIScrollView *_showView;

@implementation RootViewController

- (void)viewDidLoad

 [super viewDidLoad];

 UIImageView *showImageView = \

 [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"长图.jpg"]];

 _showView = [[UIScrollView alloc] initWithFrame:CGRectMake(0, 50, 320, 100)];

 _showView.delegate = self;

 [_showView addSubview:showImageView];

 _showView.contentSize = showImageView.frame.size;

 [self.view addSubview:_showView];

- (void)scrollViewDidScroll:(UIScrollView *)scrollView

 CGPoint point = scrollView.contentOffset;

 // 限制y轴不动

 point.y = 0.f;

 scrollView.contentOffset = point;

@end

核心代码: