ios - 将 AdMob 横幅放置在安全区域的顶部 (iPhone X)

Question

在 AdMob 中是否声明“通过修改所使用的属性和 anchor ，可以轻松地将这些技术用于限制到安全区域的顶部。”我不确定在这里要更改哪些值我知道它必须是属性和 anchor 但我不确定我应该将它们更改为什么我对约束不太熟悉

- (void)addBannerViewToView:(UIView *)bannerView {
  bannerView.translatesAutoresizingMaskIntoConstraints = NO;
  [self.view addSubview:bannerView];
  if (@available(ios 11.0, *)) {
    // In iOS 11, we need to constrain the view to the safe area.
    [self positionBannerViewFullWidthAtBottomOfSafeArea:bannerView];
  } else {
    // In lower iOS versions, safe area is not available so we use
    // bottom layout guide and view edges.
    [self positionBannerViewFullWidthAtBottomOfView:bannerView];
  }
}

#pragma mark - view positioning

- (void)positionBannerViewFullWidthAtBottomOfSafeArea:(UIView *_Nonnull)bannerView NS_AVAILABLE_IOS(11.0) {
  // Position the banner. Stick it to the bottom of the Safe Area.
  // Make it constrained to the edges of the safe area.
  UILayoutGuide *guide = self.view.safeAreaLayoutGuide;

  [NSLayoutConstraint activateConstraints:@[
    [guide.leftAnchor constraintEqualToAnchor:bannerView.leftAnchor],
    [guide.rightAnchor constraintEqualToAnchor:bannerView.rightAnchor],
    [guide.bottomAnchor constraintEqualToAnchor:bannerView.bottomAnchor]
  ]];
}

- (void)positionBannerViewFullWidthAtBottomOfView:(UIView *_Nonnull)bannerView {
  [self.view addConstraint:[NSLayoutConstraint constraintWithItem:bannerView
                                                        attribute:NSLayoutAttributeLeading
                                                        relatedBy:NSLayoutRelationEqual
                                                           toItem:self.view
                                                        attribute:NSLayoutAttributeLeading
                                                       multiplier:1
                                                         constant:0]];
  [self.view addConstraint:[NSLayoutConstraint constraintWithItem:bannerView
                                                        attribute:NSLayoutAttributeTrailing
                                                        relatedBy:NSLayoutRelationEqual
                                                           toItem:self.view
                                                        attribute:NSLayoutAttributeTrailing
                                                       multiplier:1
                                                         constant:0]];
  [self.view addConstraint:[NSLayoutConstraint constraintWithItem:bannerView
                                                        attribute:NSLayoutAttributeBottom
                                                        relatedBy:NSLayoutRelationEqual
                                                           toItem:self.bottomLayoutGuide
                                                        attribute:NSLayoutAttributeTop
                                                       multiplier:1
                                                         constant:0]];
}

Answer 1

由于 iPhoneX 附带 iOS 11.0 及更高版本，您只需修改 positionBannerViewFullWidthAtBottomOfSafeArea 函数。无需调整适用于 11 之前版本的 positionBannerViewFullWidthAtBottomOfView 函数中的约束。

改变

[guide.bottomAnchor constraintEqualToAnchor:bannerView.bottomAnchor]

到

[guide.topAnchor constraintEqualToAnchor:bannerView.topAnchor]

这会将 AdMob 横幅的顶部固定在指南的顶部。

优雅的解决方案

要缩短 admob 标准解决方案以向 View 添加横幅并设置所需的约束，以下代码段非常有用。

iOS 11 与之前版本的不同之处在于，11 引入了安全区域。 iOS 11 之前有 LayoutMargins。我们添加了一个小函数来返回安全区域指南或布局边距，并通过以下方法摆脱整个 positionBannerViewFullWidthAtBottomOfView 函数:

- (void)addBannerViewToView:(UIView *)bannerView {
  bannerView.translatesAutoresizingMaskIntoConstraints = NO;
  [self.view addSubview:bannerView];

  [self positionBannerViewFullWidthAtBottomOfSafeAreaOrLayoutMargins:bannerView];
}

#pragma mark - view positioning

- (void)positionBannerViewFullWidthAtBottomOfSafeAreaOrLayoutMargins:(UIView *_Nonnull)bannerView {
  // Position the banner. Stick it to the bottom of the Safe Area or layout margins.
  // Make it constrained to the edges of the safe area or layout margins (iOS < 11).

//Call the method to set the layout guide.

let guide = correctLayoutGuide //Swift
UILayoutGuide * guide = [self correctLayoutGuide]; //Objective-C   


  [NSLayoutConstraint activateConstraints:@[
    [guide.leftAnchor constraintEqualToAnchor:bannerView.leftAnchor],
    [guide.rightAnchor constraintEqualToAnchor:bannerView.rightAnchor],
    //[guide.topAnchor constraintEqualToAnchor:bannerView.topAnchor] // Banner at TOP
    [guide.bottomAnchor constraintEqualToAnchor:bannerView.bottomAnchor] // Banner at BOTTOM
  ]];
}


//This function returns safeAreaLayoutGuide for iOS 11 and above
//and layoutMarginsGuide for iOS < 11.

//Swift

var correctLayoutGuide: UILayoutGuide {
        if #available(iOS 11.0, *) {
            return view.safeAreaLayoutGuide
        } else {
            return view.layoutMarginsGuide
        }
}

//Objective-C

-(UILayoutGuide *) correctLayoutGuide {
    if (@available(ios 11.0, *)) {
        return [self.view safeAreaLayoutGuide];
    } else {
        return [self.view layoutMarginsGuide];
    }
}