基于Swift 3 、 Xcode 8 、 iOS 10 下的WKWebView的使用。
首先是WKWebView的基本用法：
var wk:WKWebView!
var progBar:UIProgressView! //定义的进度条
override func viewDidLoad() {
super.viewDidLoad()
self.wk = WKWebView(frame: self.view.frame)
let theConfiguration = WKWebViewConfiguration()
theConfiguration.userContentController = WKUserContentController() // 通过js与webview内容交互配置
let frame = CGRect(x: ,y : , width: self.view.frame.width, height:self.view.frame.height) //定位wk位置
wk = WKWebView(frame: frame, configuration: theConfiguration)
wk.allowsLinkPreview = true
self.wk.load(NSURLRequest(url:NSURL(string:"http://www.baidu.com/")! as URL) as URLRequest) //要在info.plist中添加对http的支持
self.view.addSubview(self.wk)
// add your self view here
// add back <- icon to back to previous page
}
上面的其实很简单，很多教程里其实都有。下面讲一下如何实现进度条。这个也不难。
//视图已经加载完后执行
override func viewDidAppear(_ animated: Bool){
super.viewDidAppear(animated) self.wk.uiDelegate = self //实现协议，进度条和获取网页标题需要用到
self.wk.navigationDelegate = self //网页间前进后退要用到 //生成进度条
progBar = UIProgressView(frame: CGRect(x: , y: , width: self.view.frame.width, height: ))
progBar.progress = 0.0
progBar.tintColor = UIColor.blue
self.view.addSubview(progBar)
//注册进度条监听事件
self.wk.addObserver(self, forKeyPath: "estimatedProgress", options: NSKeyValueObservingOptions.new, context: nil)
//注册网页标题监听事件
self.wk.addObserver(self, forKeyPath: "title", options: NSKeyValueObservingOptions.new, context: nil) }
上面的UIDelegate要在类前添加协议：
class LxxmForSwift: UIViewController, WKNavigationDelegate, WKUIDelegate， UINavigationControllerDelegate {
}
关于WKUIDelegate、UINavigationDelegate大家可以去Apple开发中心查看文档，保证会加深印象。
进度条、网页标题变动监听事件的具体实现：
//这里添加了estimatedProgrees和title两个监听事件
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
if keyPath == "estimatedProgress" {
self.progBar.alpha = 1.0
progBar.setProgress(Float(wk.estimatedProgress), animated: true)
if(self.wk.estimatedProgress >= 1.0){
UIView.animate(withDuration: 0.3, delay: 0.1, options: UIViewAnimationOptions.curveEaseInOut, animations: { () -> Void in
self.progBar.alpha = 0.0
}, completion: { (finished:Bool) -> Void in
self.progBar.progress =
})
} } else if keyPath == "title" {
self.titleForWeb.title = self.wk.title //这里titleForWeb是我自己定义的一个导航bar
print(wk.title!)
}
}
注意，添加完的监听事件需要有对应的注销事件：
override func viewWillDisappear(_ animated: Bool) {
wk.removeObserver(self, forKeyPath: "estimatedProgress")
wk.removeObserver(self, forKeyPath: "title")
}
我们都知道，WKWebView比UIWebView占用更少内存，性能更好。不过UIWebView可以直接实现JS中alert实现，而前者对JS里的alert事件重新封装了，必须实现WKUIDelegate协议：
//把这两个方法加到代码里，配合之前的 self.wk.uiDelegate = self 即可。
//监听js调用提示框
func webView(_ webView: WKWebView, runJavaScriptAlertPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping () -> Void) {
let alert = UIAlertController(title: nil, message: message, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "确定", style: .default, handler: { (action) in
completionHandler()
}))
self.present(alert, animated: true, completion: nil)
}
// 监听通过JS调用q确认框
func webView(_ webView: WKWebView, runJavaScriptConfirmPanelWithMessage message: String, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping (Bool) -> Void) {
let alert = UIAlertController(title: nil, message: message, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "确定", style: .default, handler: { (action) in
completionHandler(true)
}))
alert.addAction(UIAlertAction(title: "取消", style: .default, handler: { (action) in
completionHandler(false)
}))
self.present(alert, animated: true, completion: nil)
}
关于WKWebView中Html5图片上传，下一篇随笔我会说一下。