使用UIImageRenderingModeAlwaysOriginal图像在UITabBarItem上显示徽章的问题

Question

我正在尝试在使用UITabBarItem的图片配置的某些UIImageRenderingModeAlwaysOriginal上显示徽章。我这样做是因为期望的效果类似于凸起的UITabBarItem a-la Instagram。这是我用来测试它的代码（它在UITabBarController类别中）：

- (void) replaceImageForTab:(int)itemIndex
               defaultImage:(UIImage *)defaultImage
              selectedImage:(UIImage *)selectedImage
                      title:(NSString *)title
{
    NSArray *viewControllers = [self viewControllers];
    UIViewController *vc = [viewControllers objectAtIndex:itemIndex];
    [vc.tabBarItem setImage:[defaultImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
    [vc.tabBarItem setSelectedImage:[selectedImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
    [vc.tabBarItem setTitle:title];

    [vc.tabBarItem setBadgeValue:@"1"];
}

但是，徽章图像会被剪裁，如下所示：

我认为是因为徽章正在UITabBar的{​​{1}}中添加，并且正在剪切其内容。但我无法修改该值，因为那是私有财产。我还有其他选择吗？

Answer 1

我还没有办法改变库存徽章的偏移量，所以我不得不推出自己的解决方案。它不漂亮，但它有效（这也是UITabBarController类别）：

- (void) v_setBadgeValue:(NSString *)badgeValue inTab:(NSInteger)tabIndex
{
    NSArray *viewControllers = [self viewControllers];
    UIViewController *vc = [viewControllers objectAtIndex:tabIndex];
    UITabBarItem *tabBarItem = vc.tabBarItem;

    UIImage *normalImage = tabBarItem.image;
    UIImage *selectedImage = tabBarItem.selectedImage;

    UIImage *badgedNormalImage = [[self class] addBadgeWithValue:badgeValue toImage:normalImage];
    UIImage *badgedSelectedImage = [[self class] addBadgeWithValue:badgeValue toImage:selectedImage];

    [tabBarItem setImage:[badgedNormalImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];
    [tabBarItem setSelectedImage:[badgedSelectedImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal]];

}

+ (UIImage *) addBadgeWithValue:(NSString *)badgeValue toImage:(UIImage *)image
{
    //Here you have to create your badge view. Let's just use a red square for now
    UIView *badgeView = [[UIView alloc] initWithFrame:CGRectMake(16, 3, 14, 14)];
    [badgeView setBackgroundColor:[UIColor redColor]];

    UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
    [imageView addSubview:badgeView];

    UIGraphicsBeginImageContextWithOptions((imageView.bounds.size), NO, [[UIScreen mainScreen] scale]);
    [imageView.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return viewImage;
}

现在你可以完全控制徽章的偏移量和位置，如果你和我一样有一个非常奇怪的UITabBar可以使用，这很重要。这是结果：