1、在iOS15中，UINavigationBar默认是透明的，push和pop时导航栏有阴影，可以通过改变scrollEdgeAppearance属性直接变为模糊效果
UINavigationBar *navBar = [UINavigationBar appearance];
NSDictionary *dic =[NSDictionary dictionaryWithObjectsAndKeys: [UIFont boldSystemFontOfSize: 18],NSFontAttributeName, [UIColor blackColor],NSForegroundColorAttributeName, nil];
if (@available(iOS 15.0, *)) {
UINavigationBarAppearance *appearance = [UINavigationBarAppearance new];
appearance.backgroundColor = [UIColor whiteColor];
appearance.shadowColor = [UIColor whiteColor];
appearance.titleTextAttributes = dic;
navBar.scrollEdgeAppearance = appearance;
navBar.standardAppearance = appearance;
} else {
navBar.titleTextAttributes = dic;
[navBar setBackgroundImage:[UIImage createImageWithColor:[UIColor whiteColor]] forBarMetrics:UIBarMetricsDefault];
navBar.shadowImage = [UIImage new];
}
navBar.translucent = NO;
navBar.tintColor = [UIColor blackColor];
2、iOS15中UITableView新增了一个属性：sectionHeaderTopPadding，此属性会给section header增加一个22像素的默认高度。解决办法：
if (@available(iOS 15.0, *)) {
tableView.sectionHeaderTopPadding = 0;
}
3、TabBarItem失效
UITabBarItem *tabBarItem = [UITabBarItem appearance];
NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:DARKGRAYCOLOR,NSForegroundColorAttributeName,nil];
NSDictionary *selectAttributes =[NSDictionary dictionaryWithObjectsAndKeys:BLUECOLOR,NSForegroundColorAttributeName, nil];
if (@available(iOS 15.0, *)) {
UITabBarAppearance * appearance = [UITabBarAppearance new];
appearance.shadowColor = [UIColor clearColor];
appearance.stackedLayoutAppearance.normal.titleTextAttributes = attributes;
appearance.stackedLayoutAppearance.selected.titleTextAttributes = selectAttributes;
self.tabBar.standardAppearance = appearance;
} else {
[tabBarItem setTitleTextAttributes:attributes forState:UIControlStateNormal];
[tabBarItem setTitleTextAttributes:selectAttributes forState:UIControlStateSelected];
}
4、增加UISheetPresentationController，通过它可以控制 Modal 出来的 UIViewController 的显示大小，且可以通过拖拽手势在不同大小之间进行切换。只需要在跳转的目标 UIViewController 做如下处理：
if let presentationController = presentationController as? UISheetPresentationController {
// 显示时支持的尺寸
presentationController.detents = [.medium(), .large()]
// 显示一个指示器表示可以拖拽调整大小
presentationController.prefersGrabberVisible = true
}
5、UIButton支持更多配置
UIButton.Configuration是一个新的结构体，它指定按钮及其内容的外观和行为。它有许多与按钮外观和内容相关的属性
如cornerStyle、baseForegroundColor、baseBackgroundColor、buttonSize、title、image、subtitle、titlePadding、imagePadding、contentInsets、imagePlacement等
// Plain
let plain = UIButton(configuration: .plain(), primaryAction: nil)
plain.setTitle("Plain", for: .normal)
// Gray
let gray = UIButton(configuration: .gray(), primaryAction: nil)
gray.setTitle("Gray", for: .normal)
// Tinted
let tinted = UIButton(configuration: .tinted(), primaryAction: nil)
tinted.setTitle("Tinted", for: .normal)
// Filled
let filled = UIButton(configuration: .filled(), primaryAction: nil)
filled.setTitle("Filled", for: .normal)
7946acc91816a59256c9304e7f20d427.png
1633661669819.jpg
6、UIImageWriteToSavedPhotosAlbum存储图片之后的回调不再返回图片了，会返回nil，如果在回调方法里面操作image有可能会直接Crash，目前的解决办法声明一个全局image去记录，后面再去操作
self.image = image;
UIImageWriteToSavedPhotosAlbum(image,self,@selector(image:didFinishSavingWithError:contextInfo:), NULL);
- (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{
// self.image doing...
}
7、推出CLLocationButton用于一次性定位授权，该内容内置于CoreLocationUI模块，但如果需要获取定位的详细信息仍然需要借助于CoreLocation。
let locationButton = CLLocationButton()
// 文字
locationButton.label = .currentLocation
locationButton.fontSize = 20
// 图标
locationButton.icon = .arrowFilled
// 圆角
locationButton.cornerRadius = 10
// tint
locationButton.tintColor = UIColor.systemPink
// 背景色
locationButton.backgroundColor = UIColor.systemGreen
// 点击事件，应该再在其中发起定位请求
locationButton.addTarget(self, action: #selector(getCurrentLocation), for: .touchUpInside)
8、URLSession 推出支持 async/await 的 API，包括获取数据、上传与下载。
let session = URLSession.shared
// 加载数据
let (data, response) = try await session.data(from: url)
// 下载
let (localURL, _) = try await session.download(from: url)
// 上传
let (_, response) = try await session.upload(for: request, from: data)
9、系统图片支持多个层，支持多种渲染模式
// hierarchicalColor：多层渲染，透明度不同
let config = UIImage.SymbolConfiguration(hierarchicalColor: .systemRed)
let image = UIImage(systemName: "square.stack.3d.down.right.fill", withConfiguration: config)
// paletteColors：多层渲染，设置不同风格
let config2 = UIImage.SymbolConfiguration(paletteColors: [.systemRed, .systemGreen, .systemBlue])
let image2 = UIImage(systemName: "person.3.sequence.fill", withConfiguration: config2)
10、UIImage 新增了几个调整尺寸的方法
// preparingThumbnail
UIImage(named: "sv.png")?.preparingThumbnail(of: CGSize(width: 200, height: 100))
// prepareThumbnail，闭包中直接获取调整后的UIImage
UIImage(named: "sv.png")?.prepareThumbnail(of: CGSize(width: 200, height: 100)) { image in
// 需要回到主线程更新UI
}
// byPreparingThumbnail
await UIImage(named: "sv.png")?.byPreparingThumbnail(ofSize: CGSize(width: 100, height: 100))
