在Images.xcassets文件下的LaunchImage、AppIcon图片名称获取方法如下：

// 获取LaunchImage图片名称
static inline NSString * launchImageName() {
    CGSize screenSize = [UIScreen mainScreen].bounds.size;
    NSString *viewOrientation = @"Portrait"; //默认为竖屏，横屏设置为 @"Landscape"
    NSString *launchImageName = nil;
    NSArray *launchImages = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
    for(NSDictionary* dict in launchImages) {
        CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
        if(CGSizeEqualToSize(imageSize, screenSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]]) {
            launchImageName = dict[@"UILaunchImageName"];
        }
    }
    return launchImageName;
}
// 获取AppIcon图片名称
static inline NSString * appIconName() {
    NSArray *iconImages = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"CFBundleIcons"][@"CFBundlePrimaryIcon"][@"CFBundleIconFiles"];
    return [iconImages lastObject];
}