iOS get lauchImage

GetLaunchImage.m

    NSDictionary *launchImageNames = @{
                                       @"320x480" : @"LaunchImage-700@2x.png",
                                       @"320x568" : @"LaunchImage-700-568h@2x.png",
                                       @"375x667" : @"LaunchImage-800-667h@2x.png",
                                       @"414x736" : @"LaunchImage-800-Portrait-736h@3x.png"
                                      };
    NSString *aspect = [NSString stringWithFormat:@"%@x%@",@([UIScreen mainScreen].bounds.size.width),@([UIScreen mainScreen].bounds.size.height)];
    UIImage *launchImage = [UIImage imageNamed:launchImageNames[aspect]];