iOS 13新特性

iOS 13新特性

1. view controller present

   iOS 13以後，present的modalPresentationStyle方式變成了automatic, 呈現的方式並非全屏顯示，而是會頂部留白，默認下拉能夠dismiss。

   若是想要全屏顯示能夠以下:

   vc.modalPresentationStyle = .fullScreen
    self.present(vc, animated: true)
   複製代碼

2. 禁用暗黑模式

   將info.plist的UserInterfaceStyle的value設置爲light

3. iOS 13中禁用KVC調用私有屬性

   好比:

   let searchField: UITextField = self.searchBar.value(forKey: "")
   	let placeHolderLabel: UILabel = searchField.value(forKey: "placeHolderLabel")
    placeHolderLabel.textColor = UIColor.red
   複製代碼

   上面這個會引發crash，正確的作法：

   let textField = self.searchBar.searchTextField // in iOS 13
    let attr = NSMutableAttributedString(string: "aaaa")
    textField?.attributedPlaceholder = attr
   複製代碼

4. keyWindow

   iOS 13爲了適配多屛，若是是多屏的應用的話，那麼:

   UIApplication.shared.keyWindow 
   複製代碼

   就不該該再被使用

   @available(iOS, introduced: 2.0, deprecated: 13.0, message: "Should not be used for applications that support multiple scenes as it returns a key window across all connected scenes")
    open var keyWindow: UIWindow? { get }
   複製代碼

   取而代之的應該是:

   UIApplication.shared.windows.filter { $0.isKeyWindow }.first複製代碼