新特性介面

當我們在應用商店下載一個應用或者更新一款應用時，進入應用首先看到的是介面展示，一個炫酷的介面展示肯定會吸引眾多目光，但如何做一個比較有意思的介面呢？

1>首先建立一個控制器，繼承自UIViewController 

@interface WTNewFeatureController ()<UICollectionViewDataSource,UICollectionViewDelegate,WTNewFeatureCellDelegate>
@property (weak,nonatomic) UICollectionView * collectionView;
@property (strong,nonatomic) NSMutableArray * data;
/** 大圖片 */
@property (weak,nonatomic) UIImageView * guideImg;
/** 大文字圖片 */
@property (weak,nonatomic) UIImageView * textImg;
/** 小文字圖片 */
@property (weak,nonatomic) UIImageView * smallTextImg;

@end

@implementation WTNewFeatureController

static NSString * ID = @"Cell";


- (NSMutableArray *)data{
    
    if (_data == nil) {
        
        _data = [NSMutableArray array];
        
        for (int i = 0; i < 4; i ++) {
            
            UIImage * img = [UIImage imageNamed:[NSString stringWithFormat:@"guide%
 
[email protected]",i + 1]];
            
            [self.data addObject:img];
        }
    }
    
    return _data;
}
- (void)viewDidLoad {
    [super viewDidLoad];
    
    // 佈局樣式
    UICollectionViewFlowLayout * layout = [[UICollectionViewFlowLayout alloc] init];
    
    layout.itemSize = self.view.frame.size;
    
    layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
    
    layout.minimumLineSpacing = 0;
    
    // collectionView物件
    UICollectionView * collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:layout];
    
    // 自動分頁
    collectionView.pagingEnabled = YES;
 

    // 去除彈簧效果
    collectionView.bounces = NO;

    collectionView.backgroundColor = [UIColor whiteColor];
    // 資料來源代理
    collectionView.dataSource = self;
    collectionView.delegate = self;
    
    self.collectionView = collectionView;
    
    [self.view addSubview:collectionView];
    
    [collectionView registerClass:[WTNewFeatureCell class] forCellWithReuseIdentifier:ID];
    
    [self setUpUI];
}

- (void)setUpUI{
    
    UIImageView * guideLine = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"guideLine"]];
    
    [self.collectionView addSubview:guideLine];
//    [guideLine mas_makeConstraints:^(MASConstraintMaker *make) {
//        make.left.equalTo(self.collectionView).offset(-200);
//    }];
    guideLine.x = -200;
    
    UIImageView * guideImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"guide1"]];
    self.guideImg = guideImg;
    [self.collectionView addSubview:guideImg];
    
    UIImageView * textImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"guideLargeText1"]];
    self.textImg = textImg;
    [self.collectionView addSubview:textImg];
//    [textImg mas_makeConstraints:^(MASConstraintMaker *make) {
//        make.top.offset(self.view.frame.size.height * 0.7);
//    }];
    textImg.y = self.view.frame.size.height * 0.7;
    
    
    UIImageView * smallTextImg = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"guideSmallText1"]];
    self.smallTextImg = smallTextImg;
    [self.collectionView addSubview:smallTextImg];
//    [smallTextImg mas_makeConstraints:^(MASConstraintMaker *make) {
//        make.top.offset(self.view.frame.size.height * 0.8);
//    }];
    
     smallTextImg.y = self.view.frame.size.height * 0.8;
    
}
 

UICollectionViewDataSource方法

#pragma mark <UICollectionViewDataSource>

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 1;
}


- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    
    return self.data.count;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    
    WTNewFeatureCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:ID forIndexPath:indexPath];
    
    // 設定代理
    cell.delegate = self;
    cell.image = self.data[indexPath.item];
    
    // 判斷是否是最後一頁
    if (indexPath.item == self.data.count - 1) {
        // 顯示體驗按鈕
        cell.expersionBtn.hidden = NO;
    }else{
        
        cell.expersionBtn.hidden = YES;
    }
    return cell;
}

#pragma mark - UIScrollViewDelegate

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
    
    // 偏移量
    CGFloat offsetX = scrollView.contentOffset.x;
    
    int startX = 0;
    
    if (self.guideImg.frame.origin.x < offsetX) { // 向左移動
        
        startX = self.guideImg.frame.origin.x + scrollView.frame.size.width;
        
    }else{ // 向右移動
        
        startX = self.guideImg.frame.origin.x - scrollView.frame.size.width;
    }
    
    // 計算頁碼
    int page = offsetX / scrollView.width;
    
    // 拼接圖片名稱
    NSString *secondName = [NSString stringWithFormat:@"guide%@", @(page + 1)];
    NSString *largeName = [NSString stringWithFormat:@"guideLargeText%@", @(page + 1)];
    NSString *smallName = [NSString stringWithFormat:@"guideSmallText%@", @(page + 1)];
    
    // 修改圖片
    self.guideImg.image = [UIImage imageNamed:secondName];
    self.textImg.image = [UIImage imageNamed:largeName];
    self.smallTextImg.image = [UIImage imageNamed:smallName];
    
        [UIView animateWithDuration:0.25 animations:^{
            
            self.guideImg.x = startX;
            self.textImg.x = startX;
            self.smallTextImg.x = startX;
            
        }];
   
   
}

自定義cell的實現

.h檔案

@class WTNewFeatureCell;
@protocol WTNewFeatureCellDelegate <NSObject>
@optional
- (void)newFeatureCell:(WTNewFeatureCell *)featureCell didClickWithBtn:(UIButton *)btn;

@end
@interface WTNewFeatureCell : UICollectionViewCell
@property (weak,nonatomic) UIImage * image;
/** 立即體驗按鈕 */
@property (weak,nonatomic) UIButton * expersionBtn;

@property (weak,nonatomic) id<WTNewFeatureCellDelegate> delegate;

@interface WTNewFeatureCell ()
@property (weak,nonatomic) UIImageView * imgView;

@end
@implementation WTNewFeatureCell

- (instancetype)initWithFrame:(CGRect)frame{
    
    if (self = [super initWithFrame:frame]) {
        
       // imageView
        UIImageView * imgView = [[UIImageView alloc] init];
        self.imgView = imgView;
        [self.contentView addSubview:imgView];
        
      // 立即體驗按鈕
        UIButton * btn = [UIButton buttonWithType:UIButtonTypeCustom];
        
        [btn setImage:[UIImage imageNamed:@"guideStart"] forState:UIControlStateNormal];
        [btn sizeToFit];
        self.expersionBtn = btn;

        btn.hidden = YES;
        [btn addTarget:self action:@selector(btnClick:) forControlEvents:UIControlEventTouchUpInside];
        [self.contentView addSubview:btn];

    }
    
    return self;
}

- (void)btnClick:(UIButton *)btn{
    
    if ([self.delegate respondsToSelector:@selector(newFeatureCell:didClickWithBtn:)]) {
        
        [self.delegate newFeatureCell:self didClickWithBtn:btn];
    }
    
}
- (void)setImage:(UIImage *)image{
    
    _image = image;
    
    self.imgView.image = image;
}

- (void)layoutSubviews{
    
    self.imgView.frame = self.bounds;
    self.expersionBtn.x = (self.width - self.expersionBtn.width) * 0.5;
    self.expersionBtn.y = self.height * 0.85;
}
@end