Swift iOS : RichText

我們常常看到簡單平實的文字顯示，然後確實可以通過RichText來完成豐富文字的外觀，增強介面的表達力。

UILabel等元件，除了text屬性外，還有attributedText屬性，通過構建NSAttributedString的例項，並賦值給此屬性，就可以設定RichText了。下面是一個趁手的案例：

import UIKit
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window : UIWindow?
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        window = UIWindow()
        let nav = UINavigationController()
        window!.rootViewController = Page()
        nav.pushViewController(HomeViewController(), animated: true)
        window!.rootViewController!.view.backgroundColor = .blue
        window!.makeKeyAndVisible()
        return true
    }
}
class Page :UIViewController{
    override func viewDidLoad() {
        let label = UILabel()
        label.backgroundColor = .red
        let attrStr = try! NSAttributedString(
            data: "<b><i>text</i></b>".data(using: String.Encoding.unicode, allowLossyConversion: true)!,
            options: [ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType],
            documentAttributes: nil)
        label.attributedText = attrStr
        label.frame = CGRect(x:0,y:100,width:100,height:20)
        view.addSubview(label)
        let text = UITextView()
        let attr2 =  [NSFontAttributeName: UIFont.preferredFont(forTextStyle: UIFontTextStyle.headline), NSForegroundColorAttributeName: UIColor.purple]

        let titleString = NSAttributedString(string: "Read all about it!", attributes: attr2)
        text.attributedText = titleString
        text.frame = CGRect(x:0,y:200,width:100,height:200)
        view.addSubview(text)
    }
}複製程式碼