Biểu ngữ thông minh

智能横幅是一种广告单元,可在任意尺寸的各种设备上展示与屏幕等宽的横幅广告,无论设备屏幕是横向还是纵向都没问题。智能横幅广告会检测设备处于当前屏幕方向时的宽度,并创建该尺寸的广告视图。

iPhone 上的智能横幅广告高度为 50 分(纵向)和 32 分(横向)。在 iPad 上,竖屏和横屏的高度均为 90 点。

当图片广告不足以占据所分配的整个空间时,系统会将图片居中放置,并填充两侧的空白区域。

要使用智能横幅广告,只需为广告尺寸指定 kGADAdSizeSmartBannerPortrait(纵向)或 kGADAdSizeSmartBannerLandscape(横向)即可:

Swift

let bannerView = GADBannerView(adSize: kGADAdSizeSmartBannerPortrait)

Objective-C

GADBannerView *bannerView = [[GADBannerView alloc]
      initWithAdSize:kGADAdSizeSmartBannerPortrait];

由于 iOS 11 增加了安全区域,因此对于全宽横幅广告,您还应该为横幅广告的边缘添加限制区域。以下代码段展示了如何执行此操作:

Swift

func addBannerViewToView(_ bannerView: GADBannerView) {
  bannerView.translatesAutoresizingMaskIntoConstraints = false
  view.addSubview(bannerView)
  if #available(iOS 11.0, *) {
    // In iOS 11, we need to constrain the view to the safe area.
    positionBannerViewFullWidthAtBottomOfSafeArea(bannerView)
  }
  else {
    // In lower iOS versions, safe area is not available so we use
    // bottom layout guide and view edges.
    positionBannerViewFullWidthAtBottomOfView(bannerView)
  }
}

// MARK: - view positioning
@available (iOS 11, *)
func positionBannerViewFullWidthAtBottomOfSafeArea(_ bannerView: UIView) {
  // Position the banner. Stick it to the bottom of the Safe Area.
  // Make it constrained to the edges of the safe area.
  let guide = view.safeAreaLayoutGuide
  NSLayoutConstraint.activate([
    guide.leftAnchor.constraint(equalTo: bannerView.leftAnchor),
    guide.rightAnchor.constraint(equalTo: bannerView.rightAnchor),
    guide.bottomAnchor.constraint(equalTo: bannerView.bottomAnchor)
  ])
}

func positionBannerViewFullWidthAtBottomOfView(_ bannerView: UIView) {
  view.addConstraint(NSLayoutConstraint(item: bannerView,
                                        attribute: .leading,
                                        relatedBy: .equal,
                                        toItem: view,
                                        attribute: .leading,
                                        multiplier: 1,
                                        constant: 0))
  view.addConstraint(NSLayoutConstraint(item: bannerView,
                                        attribute: .trailing,
                                        relatedBy: .equal,
                                        toItem: view,
                                        attribute: .trailing,
                                        multiplier: 1,
                                        constant: 0))
  view.addConstraint(NSLayoutConstraint(item: bannerView,
                                        attribute: .bottom,
                                        relatedBy: .equal,
                                        toItem: bottomLayoutGuide,
                                        attribute: .top,
                                        multiplier: 1,
                                        constant: 0))
}

Objective-C

- (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]];
}