iOS 获取LaunchImage启动图

iOS开发中，LaunchImage图片会根据手机机型的不同，自动匹配对应的图片，而我们如果想要拿到对应的图片，无法直接通过图片的名字获取该启动图，而需要通过以下方式

+ (NSString *)getLaunchImageName
{
    NSString *viewOrientation = @"Portrait";
    if (UIInterfaceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation])) {
        viewOrientation = @"Landscape";
    }
    NSString *launchImageName = nil;
    NSArray* imagesDict = [[[NSBundle mainBundle] infoDictionary] valueForKey:@"UILaunchImages"];

    UIWindow *currentWindow = [[UIApplication sharedApplication].windows firstObject];
    CGSize viewSize = currentWindow.bounds.size;
    for (NSDictionary* dict in imagesDict)
    {
        CGSize imageSize = CGSizeFromString(dict[@"UILaunchImageSize"]);

        if (CGSizeEqualToSize(imageSize, viewSize) && [viewOrientation isEqualToString:dict[@"UILaunchImageOrientation"]])
        {
            launchImageName = dict[@"UILaunchImageName"];
        }
    }
    return launchImageName;
}

这些图片的格式一般是这样子的：

LaunchImage-700-568h
LaunchImage-800-667h
LaunchImage-800-Portrait-736h
LaunchImage-700
...