固定UIScrollView滑動的方向

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固定UIScrollView滑動的方向

一般而言,我們通過這兩個參數CGRectMake以及contentSize就可以自動的讓UIScrollView只往一個方向滾動.但我遇到過非常奇葩的情況,那就是即使設定的CGRectMake以及contentSize沒有一點點問題,這個UIScrollView也能夠上下左右滾動-_-!!.

為了不依賴於CGRectMake以及contentSize,我們可以通過在代理方法scrollViewDidScroll:中進行限制即可.

沒有限制之前的效果:

源碼:

////  RootViewController.m//  BUG////  Copyright (c) 2014年 Y.X. All rights reserved.//#import "RootViewController.h"@interface RootViewController ()<UIScrollViewDelegate>{    UIScrollView    *_showView;}@end@implementation RootViewController- (void)viewDidLoad{    [super viewDidLoad];    UIImageView *showImageView =         [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"長圖.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

限制後效果:

////  RootViewController.m//  BUG////  Copyright (c) 2014年 Y.X. All rights reserved.//#import "RootViewController.h"@interface RootViewController ()<UIScrollViewDelegate>{    UIScrollView    *_showView;}@end@implementation RootViewController- (void)viewDidLoad{    [super viewDidLoad];    UIImageView *showImageView =         [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"長圖.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軸不動    point.y = 0.f;        scrollView.contentOffset = point;}@end

核心代碼: