網上很多的實現方法很多都是顯示第一次的緩存的圖片，這樣就造成后臺更新廣告圖片App不能實時展示的問題。

我的具體實現思路是： 1.啟動時先獲取啟動頁的圖片全屏展示。 2.設計一個等待時間，如果超過等待時間還沒拿到圖片就把獲取的啟動頁去掉，否則就顯示廣告頁。

具體代碼的實現：

@interface SSLaunchAdView : UIView@property (nonatomic, strong) UIImageView *imageView;
///圖片的下載鏈接
@property (nonatomic, strong) NSString *imageUrl;
///廣告的顯示時間
@property (nonatomic, assign) NSInteger AdTime;
///要等待的時間
@property (nonatomic, assign) NSInteger waitTime;@property (nonatomic, copy) void(^clickImageView)(SSLaunchAdView *view);
- (id)initWithFrame:(CGRect)frameAdTime:(NSInteger)AdTimewaitTime:(NSInteger)waitTimeonView:(UIView *)onView;
///點擊廣告響應
- (void)clickImageView:(void(^)(SSLaunchAdView *view))block;
///刪除廣告頁
- (void)hideView;
@end#import "SSLaunchAdView.h"
#import "SDWebImageManager.h"@interface SSLaunchAdView ()@property (nonatomic, strong) UIImageView *bg_imageView;
@property (nonatomic, strong) NSTimer *myTimer;
@property (nonatomic, assign) NSInteger timeCount;
@property (nonatomic, strong) UIButton *button;@property (nonatomic, assign) BOOL isOutWaitTime;
@property (nonatomic, assign) BOOL isHasImage;
@end@implementation SSLaunchAdView- (id)initWithFrame:(CGRect)frame AdTime:(NSInteger)AdTime waitTime:(NSInteger)waitTime onView:(UIView *)onView{if (self = [super initWithFrame:frame]) {self.AdTime = AdTime;self.waitTime = waitTime;[onView addSubview:self];_bg_imageView = [UIImageView new];[self addSubview:_bg_imageView];[self->_bg_imageView setImage:[UIImage imageNamed:[self getLaunchImageName]]];_imageView = [UIImageView new];
//        _imageView.contentMode = UIViewContentModeScaleAspectFit;[self addSubview:_imageView];_button = [UIButton buttonWithType:UIButtonTypeCustom];[_button setTitle:@"跳過" forState:0];_button.titleLabel.font = [UIFont systemFontOfSize:12];[_button setTitleColor:[UIColor whiteColor] forState:0];_button.backgroundColor = [UIColor blackColor];[self addSubview:_button];[_button setHidden:YES];[_button addTarget:self action:@selector(buttonAction:) forControlEvents:UIControlEventTouchUpInside];_imageView.userInteractionEnabled = YES;UITapGestureRecognizer *tapImageView = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapImageView)];[_imageView addGestureRecognizer:tapImageView];if (waitTime>0) {[self performSelector:@selector(waitAction) withObject:nil afterDelay:waitTime+0.2];}}return self;
}- (void)layoutSubviews{[super layoutSubviews];self.frame = CGRectMake(0, 0, CGRectGetWidth(self.superview.frame), CGRectGetHeight(self.superview.frame));_bg_imageView.frame = CGRectMake(0, 0, CGRectGetWidth(self.superview.frame), CGRectGetHeight(self.superview.frame));_imageView.frame = CGRectMake(0, 0, CGRectGetWidth(self.superview.frame), CGRectGetHeight(self.superview.frame));if (@available(iOS 11.0, *)){_button.frame = CGRectMake(CGRectGetWidth(_imageView.frame)-50-20, _button.superview.safeAreaInsets.top+20, 50, 28);}else{_button.frame = CGRectMake(CGRectGetWidth(_imageView.frame)-50-20, 37, 50, 28);}
}- (void)buttonAction:(UIButton *)button{[self hideView];
}- (void)waitAction{@synchronized (self) {if (!self.isHasImage) {self.isOutWaitTime = YES;[self hideView];}}}- (void)tapImageView{
//    [self hideView];if (self.clickImageView) {self.clickImageView(self);}
}- (NSString *)getLaunchImageName
{CGSize viewSize = [[UIScreen mainScreen] bounds].size;// 豎屏NSString *viewOrientation = @"Portrait";NSString *launchImageName = nil;NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];for (NSDictionary* dict in imagesDict){CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]]){launchImageName = dict[@"UILaunchImageName"];}}return launchImageName;
}- (void)setImageUrl:(NSString *)imageUrl{_imageUrl = imageUrl;if (!_imageUrl) {[self hideView];return;}__weak typeof(self) weakSelf = self;[[SDWebImageManager sharedManager]loadImageWithURL:[NSURL URLWithString:_imageUrl] options:0 progress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL * _Nullable targetURL) {} completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, SDImageCacheType cacheType, BOOL finished, NSURL * _Nullable imageURL) {__strong typeof(self) strongSelf = weakSelf;if (image&&finished&&!self.isOutWaitTime) {strongSelf.imageView.image = image;strongSelf.isHasImage = YES;[strongSelf addTimer];}}];
}- (void)hideView{[self removeTimer];[UIView animateWithDuration:0.2 animations:^{self.alpha = 0;} completion:^(BOOL finished) {[self removeFromSuperview];}];
}- (void)addTimer{_myTimer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(timerAction) userInfo:nil repeats:YES];[[NSRunLoop mainRunLoop]addTimer:_myTimer forMode:NSRunLoopCommonModes];if (self.imageView.image) {[_button setHidden:NO];}
}- (void)removeTimer{[_myTimer invalidate];_myTimer = nil;
}- (void)timerAction{_timeCount ++;if (_timeCount==self.AdTime) {[self hideView];}else{[_button setTitle:[NSString stringWithFormat:@"%ld跳過",self.AdTime-_timeCount] forState:0];}
}- (void)clickImageView:(void (^)(SSLaunchAdView *))block{self.clickImageView = block;
}復制代碼