首先打开AppDelegate.m

大家都知道启动页在加载完毕会自动执行AppDelegate didFinishLaunchingWithOptions 函数：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {  
    // Override point for customization after application launch.  
    return YES;  
} 

所以直接将加载广告代码写在这个函数里面就对了：

#import "AppDelegate.h"  
  
@interface AppDelegate ()  
  
//启动页view  
@property (strong, nonatomic) UIView *LaunchView;  
  
@end  
  
@implementation AppDelegate  
  
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {  
    // Override point for customization after application launch.  
      
    //创建window  
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];  
    self.window.backgroundColor = [UIColor whiteColor];  
      
    //获取启动页  
    UIStoryboard *LaunchScreen = [UIStoryboard storyboardWithName:@"LaunchScreen" bundle:nil];  
    UIViewController *LaunchVC = [LaunchScreen instantiateInitialViewController];  
    self.LaunchView = LaunchVC.view;  
      
    //加载远程广告  
    [self loadAD];  
      
    //设置rootView  
    self.window.rootViewController = LaunchVC;  
    [self.window makeKeyAndVisible];  
      
    return YES;  
}  
  
#pragma mark 加载远程广告  
- (void)loadAD  
{  
    //远程图片地址  
    NSURL *url = [NSURL URLWithString:@"https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1486466389044&di=a7ab421bb82bd0d214bbdc5a6b79f2bf&imgtype=0&src=http%3A%2F%2Fpic.qiantucdn.com%2F58pic%2F17%2F80%2F57%2F94s58PICA7j_1024.jpg"];  
      
    //异步加载图片  
    dispatch_queue_t queue = dispatch_queue_create("loadImage", NULL);  
    dispatch_async(queue, ^{  
          
        //图片资源  
        NSData *imgData = [NSData dataWithContentsOfURL:url];  
        UIImage *img = [UIImage imageWithData:imgData];  
          
        dispatch_async(dispatch_get_main_queue(), ^{  
              
            //创建imageView  
            UIImageView *adView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, [[UIScreen mainScreen] bounds].size.width, [[UIScreen mainScreen] bounds].size.height)];  
            adView.image = img;  
              
            //添加图片点击手势  
            UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(clickAD)];  
            adView.userInteractionEnabled = YES;  
            [adView addGestureRecognizer:singleTap];  
              
            [self.LaunchView addSubview:adView];  
              
            //LaunchView前置于window  
            [self.window bringSubviewToFront:self.LaunchView];  
              
            //延迟5秒后删除广告  
            [self performSelector:@selector(removeAd) withObject:nil afterDelay:5];  
        });  
    });  
}  
  
#pragma mark 广告点击  
- (void)clickAD {  
    [self removeAd];  
}  
  
#pragma mark 删除广告  
- (void)removeAd  
{  
    [self.LaunchView removeFromSuperview];  
      
    //重新设置rootView  
    UIStoryboard *main = [UIStoryboard storyboardWithName:@"Main" bundle:nil];  
    self.window.rootViewController = [main instantiateInitialViewController];  
    [self.window makeKeyAndVisible];  
}  

PS：以上图片素材均为网上下载

最终效果：

未命名.gif

github完整Demo:
https://github.com/sg369326973/LaunchLoadAD-Demo

如果需要带缓存功能，请戳这篇：

https://www.jianshu.com/p/7af77bda3479