SwiftiOS:装入webview时，如何让图片都显示在屏幕内

webview装入的网页&＃xff0c;常常有幅面比较的图&＃xff0c;这些图会超出手机的宽度&＃xff0c;因此导致显示不完整。

比如如下案例&＃xff0c;加入了两个图片&＃xff0c;大小分别为&＃xff1a;

650x300
150x150

在iPhone SE的模拟器下&＃xff0c;默认情况下&＃xff0c;前一张图会在宽度上超出&＃xff0c;后一张可以显示完整。

import UIKit
class Page: UIViewController{var c : UIWebView!override func viewDidLoad() {super.viewDidLoad()c &＃61; UIWebView()c.frame &＃61; super.view.frameview.addSubview(c)c.frame.origin.y &＃43;&＃61; 20let html &＃61; ""let url &＃61; URL(string:"http://")c.loadHTMLString(html, baseURL: url)}
}
&＃64;UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {var window: UIWindow?func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {self.window &＃61; UIWindow(frame: UIScreen.main.bounds)self.window!.rootViewController &＃61; Page()self.window?.makeKeyAndVisible()return true}
}

想要更加优雅的适配图片&＃xff0c;可以使用css&＃xff0c;强制要求显示宽度为100%,从而缩放宽度到设备宽度。做法就是加入一个html头字符串&＃xff0c;加入到你自己装入的html字符串的头部。如&＃xff1a;

import UIKit
class Page: UIViewController{var c : UIWebView!override func viewDidLoad() {super.viewDidLoad()c &＃61; UIWebView()c.frame &＃61; super.view.frameview.addSubview(c)c.frame.origin.y &＃43;&＃61; 20let html &＃61; htmlhead &＃43; ""let url &＃61; URL(string:"http://")c.loadHTMLString(html, baseURL: url)}
}
&＃64;UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {var window: UIWindow?func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {self.window &＃61; UIWindow(frame: UIScreen.main.bounds)self.window!.rootViewController &＃61; Page()self.window?.makeKeyAndVisible()return true}
}
let htmlhead &＃61; "" &＃43;"" &＃43;"" &＃43;"" &＃43;"" &＃43;
""

出来的效果&＃xff0c;是两张图片全部充满宽度&＃xff0c;其中一个图片缩小&＃xff0c;不会产生锯齿&＃xff0c;一个图片放大&＃xff0c;有些锯齿。对于大量照片的html文档&＃xff0c;一般都是缩小的&＃xff0c;因此看起来还是过得去的。