根据Assets.xcassets里的plist文件来动态获取，具体方法如下：
//获取启动图
+ (UIImage *)getLaunchImage{
CGSize viewSize = [UIScreen mainScreen].bounds.size;
NSString *viewOr = @"Portrait";//垂直
NSString *launchImage = nil;
NSArray *launchImages = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];
for (NSDictionary *dict in launchImages) {
CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);
if (CGSizeEqualToSize(viewSize, imageSize) && [viewOr isEqualToString:dict[@"UILaunchImageOrientation"]]) {
launchImage = dict[@"UILaunchImageName"];
}
}
return [UIImage imageNamed:launchImage];
}
