ios - iOS9 旋转手机后WKWebView获取旧值Scroll Height

Question

我在单元格内有 WKWebView，但问题是当旋转手机时，我得到了 WkWebView 滚动高度的旧值，因此内容无法完全加载。

 override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
    self.contentHeights[3] = self.webView.scrollView.contentSize.height
}

此方法更改了表格单元格行的高度，但我得到的值是在旋转之前。

 func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat
{
    if indexPath.row == 3{
        return contentHeights[indexPath.row]
    }else{
        contentHeights[indexPath.row] = UITableViewAutomaticDimension
        return contentHeights[indexPath.row]
    }


}
func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    if indexPath.row == 3{
        return contentHeights[indexPath.row]
    }else{
        return UITableViewAutomaticDimension
    }
}

第3行是WkWebView Any Help???

Answer 1

我阅读了几篇文章后发现了两种解决问题的方法。

首先我使用了 KVO

addObserver(self, forKeyPath: "webView.scrollView.contentSize", options: .New, context: nil)

override func observeValueForKeyPath(keyPath: String, ofObject object: AnyObject, change: [NSObject : AnyObject], context: UnsafeMutablePointer<Void>) {
if keyPath == "webView.scrollView.contentSize" {
    if let nsSize = change[NSKeyValueChangeNewKey] as? NSValue {
        let height = nsSize.CGSizeValue().height
        // Do something here using content height.
    }
}}

removeObserver(self, forKeyPath: "webView.scrollView.contentSize", context: nil)

第二种方式是 Javascript 上的事件:

将以下代码添加到html代码中:

<script>$(document).ready(function(){$( document ).resize(function() {webkit.messageHandlers.callbackHandler.postMessage($( document ).height())});});</script>

为WkWebView添加以下配置:

var contentController:WKUserContentController!
override func loadView() {
    super.loadView()
    contentController = WKUserContentController()
    contentController.addScriptMessageHandler(
        self,
        name: "callbackHandler"
    )

    config = WKWebViewConfiguration()
    config.userContentController = contentController
    self.webView = WKWebView(frame: CGRectMake(0, 0, self.view.frame.width, self.view.frame.height), configuration: config)
}

添加以下功能:

func userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) {  
    if(message.name == "callbackHandler") {
        if !positionOrientationLanscape{
            sizeLanscape = CGFloat((message.body as! NSNumber).doubleValue)
            contentHeights[4] = sizeLanscape
        }else{
            sizePortrait = CGFloat((message.body as! NSNumber).doubleValue)
            contentHeights[4] = sizePortrait
        }
    }    
}

不要忘记 deinit

deinit {   

        self.contentController.removeScriptMessageHandlerForName("callbackHandler")
    }