相信大家都看過很多app在啟動時候會載入一些廣告圖片，例如微博、淘寶、頭條等。下邊我們就來實現類似的效果。

首先，我們要先拿到專案設定啟動頁的圖片，我們可以給UIImage寫個Category程式碼如下：

.h檔案

#import <UIKit/UIKit.h>
@interface UIImage (XLLaunchImage)
//有兩種載入啟動頁的設定方式 如果使用LaunchScreen.storyboard來設定啟動頁bIsLaunchImage 設定成NO  如果是使用LaunchImage來設定  bIsLaunchImage 設定成YES
+ (UIImage *)getLaunchImageWithbIsLaunchImage:(BOOL
 
)bIsLaunchImage;
@end

.m檔案

+ (UIImage *)getLaunchImageWithbIsLaunchImage:(BOOL)bIsLaunchImage
{
    if (!bIsLaunchImage) {
       // 通過LaunchScreen.StoryBoard載入的本地圖片 只需要兩張本地圖片iPhone 7和 7 plus尺寸的圖 取名為[email protected] 和[email protected]
        UIViewController *viewController = [[UIStoryboard storyboardWithName:@"LaunchScreen"
 
 bundle:nil] instantiateViewControllerWithIdentifier:@"LaunchScreen"];
        UIImageView * imageView=viewController.view.subviews[0];
        return imageView.image;
    }else{
        //下面是通過LaunchImage 獲取的本地圖片 需要四張本地圖片 放入LaunchImage即可  不包括橫屏和豎屏
        NSString *viewOrientation = @"Portrait";
        //    if (UIInterfaceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation])) {
 

        //        viewOrientation = @"Landscape";
        //    }
        NSString *launchImageName = nil;
        NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
        CGSize viewSize = [UIApplication sharedApplication].keyWindow.bounds.size;
        for (NSDictionary* dict in imagesDict)
        {
            CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
            if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
            {
                launchImageName = dict[@"UILaunchImageName"];
            }
        }
        return [UIImage imageNamed:launchImageName];
    }
}

這邊要說明一下，設定啟動頁有兩種方式一種是通過LaunchScreen.storyboard來設定，一種是通過LaunchImage（也就是Launch images source）來設定這兩個我們獲取的方式是不一樣的。

接著我們要來建立一個View類，用於展示我們自定義的廣告圖片。程式碼如下：

.h檔案

#import <UIKit/UIKit.h>
#import "FLAnimatedImage.h"

//螢幕高度
#define kScreenHeight CGRectGetHeight([UIScreen mainScreen].bounds)
//螢幕寬度
#define kScreenWidth CGRectGetWidth([UIScreen mainScreen].bounds)
//跳過按鈕寬
#define kSkipBtnWidth 65
//跳過按鈕高
#define kSkipBtnHeight 30
//跳過按鈕右邊距
#define kSkipRightEdging 20
//跳過按鈕頂部邊距
#define kSkipTopEdging 40
//預設廣告頁面高度
#define kAdImageViewHeight kScreenHeight-100

@interface XLLaunchView : UIView
@property (nonatomic, weak) UIImageView *launchImageView;

@property (nonatomic, weak) FLAnimatedImageView *adImageView;

@property (nonatomic, weak) UIButton *skipBtn;
@end

.m檔案

#import "XLLaunchView.h"
@interface XLLaunchView ()
@end
@implementation XLLaunchView
- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {

        [self addlaunchImageView];

        [self addAdImageView];

        [self addSkipBtn];
    }

    return self;
}
- (void)addlaunchImageView
{
    UIImageView *imageView = [[UIImageView alloc]init];
    [self addSubview:imageView];
    _launchImageView = imageView;
}

- (void)addAdImageView
{
    FLAnimatedImageView *imageView = [[FLAnimatedImageView alloc]init];
    [self addSubview:imageView];
    _adImageView = imageView;
}

//跳過按鈕
- (void)addSkipBtn
{
    UIButton *skipBtn = [UIButton buttonWithType:UIButtonTypeCustom];
    skipBtn.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:0.3];
    [skipBtn setTitle:@"跳過" forState:UIControlStateNormal];
    skipBtn.titleLabel.textColor = [UIColor whiteColor];
    skipBtn.titleLabel.font = [UIFont systemFontOfSize:15];
    skipBtn.alpha = 0.92;
    skipBtn.layer.cornerRadius = 4.0;
    skipBtn.clipsToBounds = YES;
    [self addSubview:skipBtn];
    _skipBtn = skipBtn;
}

- (void)layoutSubviews
{
    [super layoutSubviews];
    _launchImageView.frame = self.bounds;
    _adImageView.frame = CGRectMake(0, 0, kScreenWidth, kScreenHeight-100);
    _skipBtn.frame = CGRectMake(CGRectGetWidth(self.frame) - kSkipBtnWidth - kSkipRightEdging, kSkipTopEdging, kSkipBtnWidth, kSkipBtnHeight);
}
@end

這邊也要說明一下，我們這邊圖片是通過SDWebImage來進行載入的，而FLAnimatedImage.h這個類是SDWebImage4.0版本以上載入動態圖的類，效能比之前的提升了很多，具體的使用這裡不多說請點SDWebImage使用

最後，我們可以建立一個LaunchImageVIew的管理者，方便我們來進行一些對應的操作。程式碼如下：

.h檔案

#import <UIKit/UIKit.h>

//廣告倒計時間 單位：秒
#define DURATION 5
@class XLAdModel;
@interface XLLaunchViewManager : UIView
//廣告模型
@property (nonatomic , strong) XLAdModel  *adModel;
//點選廣告圖回撥
@property (nonatomic , copy) void(^tapClick) ();
//建立一個物件
+(instancetype)launchViewManger;
//展示物件
-(void)showView:(UIView *)view;
@end

.m檔案

#import "XLLaunchViewManager.h"
#import "XLLaunchView.h"
#import "UIImageView+WebCache.h"
#import "UIImage+XLLaunchImage.h"
#import "XLAdModel.h"
#import "FLAnimatedImageView+WebCache.h"
@interface XLLaunchViewManager ()
@property (nonatomic, weak) XLLaunchView *launchView;
@property (nonatomic, strong) dispatch_source_t timer;
@end

@implementation XLLaunchViewManager
+(instancetype)launchViewManger
{
    return [[[ self class]alloc]init];
}

-(void)showView:(UIView *)view
{
    self.frame = view.bounds;
    [view addSubview:self];
    [self addADLaunchView];
    [self loadData];
}

- (void)addADLaunchView
{
    XLLaunchView *adLaunchView = [[XLLaunchView alloc]init];
    adLaunchView.skipBtn.hidden = YES;
    //有兩種載入啟動頁的設定方式 如果使用LaunchScreen.storyboard來設定啟動頁bIsLaunchImage 設定成NO  如果是使用LaunchImage來設定  bIsLaunchImage 設定成YES
    adLaunchView.launchImageView.image = [UIImage getLaunchImageWithbIsLaunchImage:YES];
    adLaunchView.frame = self.bounds;
    [adLaunchView.skipBtn addTarget:self action:@selector(skipADAction) forControlEvents:UIControlEventTouchUpInside];
    [self addSubview:adLaunchView];
    _launchView = adLaunchView;
}

//載入資料
- (void)loadData
{
    if ( _adModel.launchUrl && _adModel.launchUrl.length>0) {
        [self showADImageWithURL:[NSURL URLWithString:_adModel.launchUrl]];
        UITapGestureRecognizer * tap=[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(pushAdController)];
        [_launchView addGestureRecognizer:tap];
    }else{
        [self dismissController];
    }
}

//設定廣告圖片
- (void)showADImageWithURL:(NSURL *)url
{
    __weak typeof(self) weakSelf = self;
    [_launchView.adImageView  sd_setImageWithURL:url placeholderImage:nil options:SDWebImageRetryFailed completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
        // 啟動倒計時
        [weakSelf scheduledGCDTimer];
    }];
}

//跳過倒計時
- (void)showSkipBtnTitleTime:(int)timeLeave
{
    NSString *timeLeaveStr = [NSString stringWithFormat:@"跳過 %ds",timeLeave];
    [_launchView.skipBtn setTitle:timeLeaveStr forState:UIControlStateNormal];
    _launchView.skipBtn.hidden = NO;
}


- (void)scheduledGCDTimer
{
    [self cancleGCDTimer];
    __block int timeLeave = DURATION; //倒計時時間
    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    _timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0,queue);
    dispatch_source_set_timer(_timer,dispatch_walltime(NULL, 0),1.0*NSEC_PER_SEC, 0); //每秒執行
    __typeof (self) __weak weakSelf = self;
    dispatch_source_set_event_handler(_timer, ^{
        if(timeLeave <= 0){ //倒計時結束，關閉
            dispatch_source_cancel(weakSelf.timer);
            dispatch_async(dispatch_get_main_queue(), ^{
                //關閉介面
                [self dismissController];
            });
        }else{
            int curTimeLeave = timeLeave;
            dispatch_async(dispatch_get_main_queue(), ^{
                //設定介面
                [weakSelf showSkipBtnTitleTime:curTimeLeave];
            });
            --timeLeave;
        }
    });
    dispatch_resume(_timer);
}

- (void)cancleGCDTimer
{
    if (_timer) {
        dispatch_source_cancel(_timer);
        _timer = nil;
    }
}

#pragma mark - action

- (void)skipADAction
{
    [self dismissController];
}

- (void)dismissController
{
    [self cancleGCDTimer];
    //消失動畫
    [UIView animateWithDuration:0.0 delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{
        //縮放修改處
        self.transform = CGAffineTransformMakeScale(1, 1);
        self.alpha = 0.0;
    } completion:^(BOOL finished) {
        [self removeFromSuperview];
    }];
}

-(void)pushAdController
{
    dispatch_async(dispatch_get_main_queue(), ^{
        [self removeFromSuperview];
      if (self.tapClick) {
            self.tapClick();
        }
    });
}

- (void)dealloc
{
    [self cancleGCDTimer];
}

-(void)show
{
    [self addADLaunchView];
    [self loadData];
}
@end

這邊有個XLAdModel類，這個是廣告Model引數如下

@interface XLAdModel : NSObject
//啟動圖廣告地址
@property (nonatomic , copy) NSString *launchUrl;
//啟動圖廣告詳情地址
@property (nonatomic , copy) NSString *adDetailUrl;
@end

到這邊我們是準備都完成，接下來就是怎麼來使用了，使用程式碼如下：
AppDelegate.m檔案

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    [self addMainWindow];
    [self addADLaunchController];
    return YES;
}

- (void)addMainWindow
{
    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
    self.window.backgroundColor = [UIColor whiteColor];
    _nav = [[UINavigationController alloc] initWithRootViewController:[[MainViewController alloc] init]];
    self.window.rootViewController = _nav;
    [self.window makeKeyAndVisible];
}

//載入廣告
- (void)addADLaunchController
{
    XLAdModel * adModel=[[XLAdModel alloc]init];
    //靜態圖
//    adModel.launchUrl = @"http://d.hiphotos.baidu.com/image/pic/item/f7246b600c3387444834846f580fd9f9d72aa034.jpg";
    //動態圖
    adModel.launchUrl = @"https://ss0.bdstatic.com/70cFuHSh_Q1YnxGkpoWK1HF6hhy/it/u=408862874,416826962&fm=23&gp=0.jpg";
//    //點選跳轉連結
    adModel.adDetailUrl = @"http://www.baidu.com";
    UIViewController *rootViewController = self.window.rootViewController;
    XLLaunchViewManager *launchController = [XLLaunchViewManager launchViewManger];
    launchController.adModel = adModel;
    [launchController showView:rootViewController.view];
    __weak typeof(self)weakSelf = self;
    launchController.tapClick =^{
        XLAdViewController * adVc=[[XLAdViewController alloc]init];
        adVc.adModel = adModel;
        adVc.hidesBottomBarWhenPushed=YES;
        [weakSelf.nav pushViewController:adVc animated:YES];
    };
}

這邊的XLAdViewController是廣告的具體詳情頁面，具體可自己實現。到這邊就基本可以完成了，效果如下：