iOS面试iOS精品文章-面试寒哥管理的技术专题

iOS笔试-上机题（附个人见解）

2015-11-12  本文已影响6650人  Developer_Yancy
随机配图

机试题目如下

用命令行创建一个以CocoaPods管理的项目【Test-你的姓名拼音】，新建3个ViewController，完成以下题目

参考思路

1.新建以CocoaPods管理的项目

PS:下面只写思路，由于有点强迫症，想把题目做的完整一点，时间又不允许，就只把思路写写就好了

2.第一题（创建一个TableViewController）

上面的Demo骨架已经搭完了，下面是解析一下问题的答案（当然，这些问题都可以从网上直接找到答案，这里只是简单说说我个人的理解，如有纰漏，欢迎指正）

请使用UIScrollerView控件实现图片的循环切换

- CYXInfiniteScrollView.h文件

#import <UIKit/UIKit.h>

@interface CYXInfiniteScrollView : UIView
@property (strong, nonatomic) NSArray *images;
@property (weak, nonatomic, readonly) UIPageControl *pageControl;
@property (assign, nonatomic, getter=isScrollDirectionPortrait) BOOL scrollDirectionPortrait;
@end

- CYXInfiniteScrollView.m文件

#import "CYXInfiniteScrollView.h"

static int const ImageViewCount = 3;

@interface CYXInfiniteScrollView() <UIScrollViewDelegate>
@property (weak, nonatomic) UIScrollView *scrollView;
@end

@implementation CYXInfiniteScrollView

- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        // 滚动视图
        UIScrollView *scrollView = [[UIScrollView alloc] init];
        scrollView.showsHorizontalScrollIndicator = NO;
        scrollView.showsVerticalScrollIndicator = NO;
        scrollView.pagingEnabled = YES;
        scrollView.bounces = NO;
        scrollView.delegate = self;
        [self addSubview:scrollView];
        self.scrollView = scrollView;

        // 图片控件
        for (int i = 0; i<ImageViewCount; i++) {
            UIImageView *imageView = [[UIImageView alloc] init];
            [scrollView addSubview:imageView];
        }

        // 页码视图
        UIPageControl *pageControl = [[UIPageControl alloc] init];
        [self addSubview:pageControl];
        _pageControl = pageControl;
    }
    return self;
}

- (void)layoutSubviews
{
    [super layoutSubviews];

    self.scrollView.frame = self.bounds;
    if (self.isScrollDirectionPortrait) {
        self.scrollView.contentSize = CGSizeMake(0, ImageViewCount * self.bounds.size.height);
    } else {
        self.scrollView.contentSize = CGSizeMake(ImageViewCount * self.bounds.size.width, 0);
    }

    for (int i = 0; i<ImageViewCount; i++) {
        UIImageView *imageView = self.scrollView.subviews[i];

        if (self.isScrollDirectionPortrait) {
            imageView.frame = CGRectMake(0, i * self.scrollView.frame.size.height, self.scrollView.frame.size.width, self.scrollView.frame.size.height);
        } else {
            imageView.frame = CGRectMake(i * self.scrollView.frame.size.width, 0, self.scrollView.frame.size.width, self.scrollView.frame.size.height);
        }
    }

    CGFloat pageW = 100;
    CGFloat pageH = 100;
    CGFloat pageX = self.scrollView.frame.size.width - pageW;
    CGFloat pageY = self.scrollView.frame.size.height - pageH;
    self.pageControl.frame = CGRectMake(pageX, pageY, pageW, pageH);

    [self updateContent];
}

- (void)setImages:(NSArray *)images
{
    _images = images;

    // 设置页码
    self.pageControl.numberOfPages = images.count;
    self.pageControl.currentPage = 0;

    // 设置内容
    [self updateContent];
}

#pragma mark - <UIScrollViewDelegate>
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    // 找出最中间的那个图片控件
    NSInteger page = 0;
    CGFloat minDistance = MAXFLOAT;
    for (int i = 0; i<self.scrollView.subviews.count; i++) {
        UIImageView *imageView = self.scrollView.subviews[i];
        CGFloat distance = 0;
        if (self.isScrollDirectionPortrait) {
            distance = ABS(imageView.frame.origin.y - scrollView.contentOffset.y);
        } else {
            distance = ABS(imageView.frame.origin.x - scrollView.contentOffset.x);
        }
        if (distance < minDistance) {
            minDistance = distance;
            page = imageView.tag;
        }
    }
    self.pageControl.currentPage = page;
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    [self updateContent];
}

- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView
{
    [self updateContent];
}

#pragma mark - 内容更新
- (void)updateContent
{
    // 设置图片
    for (int i = 0; i<self.scrollView.subviews.count; i++) {
        UIImageView *imageView = self.scrollView.subviews[i];
        NSInteger index = self.pageControl.currentPage;
        if (i == 0) {
            index--;
        } else if (i == 2) {
            index++;
        }
        if (index < 0) {
            index = self.pageControl.numberOfPages - 1;
        } else if (index >= self.pageControl.numberOfPages) {
            index = 0;
        }
        imageView.tag = index;
        imageView.image = self.images[index];
    }

    // 设置偏移量在中间
    if (self.isScrollDirectionPortrait) {
        self.scrollView.contentOffset = CGPointMake(0, self.scrollView.frame.size.height);
    } else {
        self.scrollView.contentOffset = CGPointMake(self.scrollView.frame.size.width, 0);
    }
}

请使用UICollectionView控件实现图片数据绑定，要求每行两列


#import "CYXCollectionViewController.h"

@interface CYXCollectionViewController ()

@end

@implementation CYXCollectionViewController

static NSString * const CYXCell = @"cell";

- (instancetype)init
{
    // 流水布局
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];

    layout.itemSize = CGSizeMake(150, 150);

    layout.minimumLineSpacing = 0;

    layout.minimumInteritemSpacing = 20;

    layout.sectionInset = UIEdgeInsetsMake(20, 0, 0, 0);

    return [self initWithCollectionViewLayout:layout];
}

- (void)viewDidLoad {
    [super viewDidLoad];

    self.collectionView.backgroundColor = [UIColor whiteColor];

    // 注册cell
    [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier: CYXCell];

}

#pragma mark - <UICollectionViewDataSource>

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return 30;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{

   UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier: CYXCell forIndexPath:indexPath];
    UIImageView *view = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"xxx"]];
    cell.backgroundView = view;
    return cell;
}
@end
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