iOS动态图片启动页

  在application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 这个方法里面写,一般放在最后

NSString *docPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)firstObject];
    //拼接文件名
    NSString *detailPath = [docPath stringByAppendingPathComponent:@"launchScreen.png"];
    
    NSFileManager *manager = [NSFileManager defaultManager];
    BOOL exist = [manager fileExistsAtPath:detailPath];
    if (exist) {
        NSLog(@"%@",@"启动图片存在");
        UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.window.frame.size.width, self.window.frame.size.height)];

        imageView.image = [UIImage imageWithContentsOfFile:detailPath];
        [self.window addSubview:imageView];
        
        [UIView animateWithDuration:1 delay:1 options:0 animations:^{
            imageView.alpha = 0;
            //加特效
            //imageView.layer.transform = CATransform3DScale(CATransform3DIdentity, 1.5, 1.5, 1);
        } completion:^(BOOL finished) {
            [imageView removeFromSuperview];
        }];
    } else {
        NSLog(@"%@",@"启动图不存在,重新下载");
        
        dispatch_async(dispatch_get_global_queue(0, 0), ^{
            NSString *url = @"http://img.taopic.com/uploads/allimg/110812/1820-110Q20I63022.jpg";
            NSData *data = [NSData dataWithContentsOfURL:[NSURL URLWithString:url]];
            UIImage *image = [UIImage imageWithData:data];
            //保存图片到Document
            [UIImagePNGRepresentation(image) writeToFile:detailPath atomically:YES];
        });
        
        
    }