如何检测正在 WKWebView 中播放的电影？
How to detect a movie being played in a WKWebView?
我想知道是否可以在 WKWebView 中检测到正在播放的电影？
另外我想知道打开流的确切 URL？
由于这个问题的解决方案需要大量的研究和不同的方法，我想在这里记录它以供其他人遵循我的想法。 如果您只对最终解决方案感兴趣，请查找一些花哨的标题。
我开始使用的应用程序非常简单。这是一个 Single-View 应用程序，它导入 WebKit 并打开一个 WKWebView 和一些 NSURL:
import UIKit
import WebKit
class ViewController: UIViewController {
var webView: WKWebView!
override func viewDidAppear(animated: Bool) {
webView = WKWebView()
view = webView
let request = NSURLRequest(URL: NSURL(string: "http://tinas-burger.tumblr.com/post/133991473113")!)
webView.loadRequest(request)
}
}
The URL includes a video that is (kind of) protected by JavaScript. I really haven't seen the video yet, it was just the first I discovered. Remember to add NSAppTransportSecurity and NSAllowsArbitraryLoads to your Info.plist or you will see a blank page.
WKNavigationDelegate
WKNavigationDelegate 不会通知您正在播放视频。因此设置 webView.navigationDelegate = self 并实施协议不会给您带来预期的结果。
NSNotificationCenter
我假设一定有像SomeVideoPlayerDidOpen这样的事件。不幸的是没有，但它可能有一个 SomeViewDidOpen 事件，所以我开始检查视图层次结构：
UIWindow
UIWindow
WKWebView
WKScrollView
...
...
UIWindow
UIWindow
UIView
AVPlayerView
UITransitionView
UIView
UIView
UIView
...
UIView
...
AVTouchIgnoringView
...
正如预期的那样，将添加一个额外的 UIWindow， 可能 有一个事件，是的，它确实有！
我通过添加一个新的观察者扩展了 viewDidAppear:：
NSNotificationCenter.defaultCenter().addObserver(self, selector: "windowDidBecomeVisible:", name: UIWindowDidBecomeVisibleNotification, object: nil)
并添加了对应的方法：
func windowDidBecomeVisible(notification: NSNotification) {
for mainWindow in UIApplication.sharedApplication().windows {
for mainWindowSubview in mainWindow.subviews {
// this will print:
// 1: `WKWebView` + `[WKScrollView]`
// 2: `UIView` + `[]`
print("\(mainWindowSubview) \(mainWindowSubview.subviews)")
}
正如预期的那样，它 returns 我们之前检查过的视图层次结构。但不幸的是，AVPlayerView 似乎将在稍后创建。
如果您相信您的应用程序唯一 UIWindow 它会打开的是媒体播放器，那么您到这里就完成了。但是这个解决方案不会让我晚上睡不着觉，所以让我们更深入...
注入事件
我们需要收到关于 AVPlayerView 被添加到这个无名 UIView 的通知。很明显 AVPlayerView 必须是 UIView 的子类，但由于它没有被 Apple 正式记录，我检查了 iOS Runtime Headers for AVPlayerView 并且肯定 是 UIView.
现在我们知道 AVPlayerView 是 UIView 的子类，它可能会通过调用 addSubview: 添加到无名 UIView 中。所以我们必须得到有关添加的视图的通知。不幸的是 UIView 没有提供一个事件来观察。但它 确实 调用了一个名为 didAddSubview: 的方法，这可能非常方便。
所以让我们检查一下 AVPlayerView 是否会添加到我们的应用程序中的某处并发送通知：
let originalDidAddSubviewMethod = class_getInstanceMethod(UIView.self, "didAddSubview:")
let originalDidAddSubviewImplementation = method_getImplementation(originalDidAddSubviewMethod)
typealias DidAddSubviewCFunction = @convention(c) (AnyObject, Selector, UIView) -> Void
let castedOriginalDidAddSubviewImplementation = unsafeBitCast(originalDidAddSubviewImplementation, DidAddSubviewCFunction.self)
let newDidAddSubviewImplementationBlock: @convention(block) (AnyObject!, UIView) -> Void = { (view: AnyObject!, subview: UIView) -> Void in
castedOriginalDidAddSubviewImplementation(view, "didAddsubview:", subview)
if object_getClass(view).description() == "AVPlayerView" {
NSNotificationCenter.defaultCenter().postNotificationName("PlayerWillOpen", object: nil)
}
}
let newDidAddSubviewImplementation = imp_implementationWithBlock(unsafeBitCast(newDidAddSubviewImplementationBlock, AnyObject.self))
method_setImplementation(originalDidAddSubviewMethod, newDidAddSubviewImplementation)
现在我们可以观察通知并接收相应的事件：
NSNotificationCenter.defaultCenter().addObserver(self, selector: "playerWillOpen:", name: "PlayerWillOpen", object: nil)
func playerWillOpen(notification: NSNotification) {
print("A Player will be opened now")
}
更好的通知注入
由于 AVPlayerView 不会被删除而只会被释放，我们将不得不稍微重写我们的代码并向 AVPlayerViewController 注入一些通知。这样我们就可以收到任意多的通知，例如：PlayerWillAppear 和 PlayerWillDisappear:
let originalViewWillAppearMethod = class_getInstanceMethod(UIViewController.self, "viewWillAppear:")
let originalViewWillAppearImplementation = method_getImplementation(originalViewWillAppearMethod)
typealias ViewWillAppearCFunction = @convention(c) (UIViewController, Selector, Bool) -> Void
let castedOriginalViewWillAppearImplementation = unsafeBitCast(originalViewWillAppearImplementation, ViewWillAppearCFunction.self)
let newViewWillAppearImplementationBlock: @convention(block) (UIViewController!, Bool) -> Void = { (viewController: UIViewController!, animated: Bool) -> Void in
castedOriginalViewWillAppearImplementation(viewController, "viewWillAppear:", animated)
if viewController is AVPlayerViewController {
NSNotificationCenter.defaultCenter().postNotificationName("PlayerWillAppear", object: nil)
}
}
let newViewWillAppearImplementation = imp_implementationWithBlock(unsafeBitCast(newViewWillAppearImplementationBlock, AnyObject.self))
method_setImplementation(originalViewWillAppearMethod, newViewWillAppearImplementation)
let originalViewWillDisappearMethod = class_getInstanceMethod(UIViewController.self, "viewWillDisappear:")
let originalViewWillDisappearImplementation = method_getImplementation(originalViewWillDisappearMethod)
typealias ViewWillDisappearCFunction = @convention(c) (UIViewController, Selector, Bool) -> Void
let castedOriginalViewWillDisappearImplementation = unsafeBitCast(originalViewWillDisappearImplementation, ViewWillDisappearCFunction.self)
let newViewWillDisappearImplementationBlock: @convention(block) (UIViewController!, Bool) -> Void = { (viewController: UIViewController!, animated: Bool) -> Void in
castedOriginalViewWillDisappearImplementation(viewController, "viewWillDisappear:", animated)
if viewController is AVPlayerViewController {
NSNotificationCenter.defaultCenter().postNotificationName("PlayerWillDisappear", object: nil)
}
}
let newViewWillDisappearImplementation = imp_implementationWithBlock(unsafeBitCast(newViewWillDisappearImplementationBlock, AnyObject.self))
method_setImplementation(originalViewWillDisappearMethod, newViewWillDisappearImplementation)
现在我们可以观察到这两个通知，一切顺利：
NSNotificationCenter.defaultCenter().addObserver(self, selector: "playerWillAppear:", name: "PlayerWillAppear", object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "playerWillDisappear:", name: "PlayerWillDisappear", object: nil)
func playerWillAppear(notification: NSNotification) {
print("A Player will be opened now")
}
func playerWillDisappear(notification: NSNotification) {
print("A Player will be closed now")
}
视频URL
我花了几个小时挖掘一些 iOS 运行时 Headers 来猜测我在哪里可以找到指向视频的 URL，但我无法找到它.当我深入研究 WebKit 本身的一些源文件时，我不得不放弃并接受没有 简单的方法 来做到这一点，虽然我相信它隐藏在某个地方并且可以到达，但是很可能需要付出很多努力。
我尝试将一些用户脚本添加（注入）到 WKWebView，这种方式比方法混合更安全：
相关代码如下：
let contentController = WKUserContentController()
if let jsSource = NSBundle.mainBundle().URLForResource("video_play_messenger", withExtension: "js"),
let jsSourceString = try? String(contentsOfURL: jsSource) {
let userScript = WKUserScript(source: jsSourceString, injectionTime: .AtDocumentEnd, forMainFrameOnly: true)
contentController.addUserScript(userScript)
contentController.addScriptMessageHandler(self, name: "callbackHandler")
}
let webConfiguration = WKWebViewConfiguration()
webConfiguration.userContentController = contentController
webView = WKWebView(frame: CGRect.zero, configuration: webConfiguration)
let request = NSURLRequest(URL: NSURL(string: "URL_FOR_VIDEO")!)
webView.loadRequest(request)
对于WKWebView的controller，符合WKScriptMessageHandler实现这个方法：
func userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) {
if message.name == "callbackHandler" {
if let messageString = message.body as? String where messageString == "VideoIsPlaying" {
// Vide is being played
}
}
}
将 video_play_messenger.js 添加到您的项目：
function videoTags() {
return document.getElementsByTagName("video");
}
function setupVideoPlayingHandler() {
try {
var videos = videoTags()
for (var i = 0; i < videos.length; i++) {
videos.item(i).onplaying = function() {
webkit.messageHandlers.callbackHandler.postMessage("VideoIsPlaying");
}
}
} catch (error) {
console.log(error);
}
}
function setupVidePlayingListener() {
// If we have video tags, setup onplaying handler
if (videoTags().length > 0) {
setupVideoPlayingHandler();
return
}
// Otherwise, wait for 100ms and check again.
setTimeout(setupVidePlayingListener, 100);
}
setupVidePlayingListener();
参考：http://www.kinderas.com/technology/2014/6/15/wkwebview-and-javascript-in-ios-8-using-swift
我想知道是否可以在 WKWebView 中检测到正在播放的电影？
另外我想知道打开流的确切 URL？
由于这个问题的解决方案需要大量的研究和不同的方法，我想在这里记录它以供其他人遵循我的想法。 如果您只对最终解决方案感兴趣，请查找一些花哨的标题。
我开始使用的应用程序非常简单。这是一个 Single-View 应用程序，它导入 WebKit 并打开一个 WKWebView 和一些 NSURL:
import UIKit
import WebKit
class ViewController: UIViewController {
var webView: WKWebView!
override func viewDidAppear(animated: Bool) {
webView = WKWebView()
view = webView
let request = NSURLRequest(URL: NSURL(string: "http://tinas-burger.tumblr.com/post/133991473113")!)
webView.loadRequest(request)
}
}
The URL includes a video that is (kind of) protected by JavaScript. I really haven't seen the video yet, it was just the first I discovered. Remember to add
NSAppTransportSecurityandNSAllowsArbitraryLoadsto yourInfo.plistor you will see a blank page.
WKNavigationDelegate
WKNavigationDelegate 不会通知您正在播放视频。因此设置 webView.navigationDelegate = self 并实施协议不会给您带来预期的结果。
NSNotificationCenter
我假设一定有像SomeVideoPlayerDidOpen这样的事件。不幸的是没有，但它可能有一个 SomeViewDidOpen 事件，所以我开始检查视图层次结构：
UIWindow
UIWindow
WKWebView
WKScrollView
...
...
UIWindow
UIWindow
UIView
AVPlayerView
UITransitionView
UIView
UIView
UIView
...
UIView
...
AVTouchIgnoringView
...
正如预期的那样，将添加一个额外的 UIWindow， 可能 有一个事件，是的，它确实有！
我通过添加一个新的观察者扩展了 viewDidAppear:：
NSNotificationCenter.defaultCenter().addObserver(self, selector: "windowDidBecomeVisible:", name: UIWindowDidBecomeVisibleNotification, object: nil)
并添加了对应的方法：
func windowDidBecomeVisible(notification: NSNotification) {
for mainWindow in UIApplication.sharedApplication().windows {
for mainWindowSubview in mainWindow.subviews {
// this will print:
// 1: `WKWebView` + `[WKScrollView]`
// 2: `UIView` + `[]`
print("\(mainWindowSubview) \(mainWindowSubview.subviews)")
}
正如预期的那样，它 returns 我们之前检查过的视图层次结构。但不幸的是，AVPlayerView 似乎将在稍后创建。
如果您相信您的应用程序唯一 UIWindow 它会打开的是媒体播放器，那么您到这里就完成了。但是这个解决方案不会让我晚上睡不着觉，所以让我们更深入...
注入事件
我们需要收到关于 AVPlayerView 被添加到这个无名 UIView 的通知。很明显 AVPlayerView 必须是 UIView 的子类，但由于它没有被 Apple 正式记录，我检查了 iOS Runtime Headers for AVPlayerView 并且肯定 是 UIView.
现在我们知道 AVPlayerView 是 UIView 的子类，它可能会通过调用 addSubview: 添加到无名 UIView 中。所以我们必须得到有关添加的视图的通知。不幸的是 UIView 没有提供一个事件来观察。但它 确实 调用了一个名为 didAddSubview: 的方法，这可能非常方便。
所以让我们检查一下 AVPlayerView 是否会添加到我们的应用程序中的某处并发送通知：
let originalDidAddSubviewMethod = class_getInstanceMethod(UIView.self, "didAddSubview:")
let originalDidAddSubviewImplementation = method_getImplementation(originalDidAddSubviewMethod)
typealias DidAddSubviewCFunction = @convention(c) (AnyObject, Selector, UIView) -> Void
let castedOriginalDidAddSubviewImplementation = unsafeBitCast(originalDidAddSubviewImplementation, DidAddSubviewCFunction.self)
let newDidAddSubviewImplementationBlock: @convention(block) (AnyObject!, UIView) -> Void = { (view: AnyObject!, subview: UIView) -> Void in
castedOriginalDidAddSubviewImplementation(view, "didAddsubview:", subview)
if object_getClass(view).description() == "AVPlayerView" {
NSNotificationCenter.defaultCenter().postNotificationName("PlayerWillOpen", object: nil)
}
}
let newDidAddSubviewImplementation = imp_implementationWithBlock(unsafeBitCast(newDidAddSubviewImplementationBlock, AnyObject.self))
method_setImplementation(originalDidAddSubviewMethod, newDidAddSubviewImplementation)
现在我们可以观察通知并接收相应的事件：
NSNotificationCenter.defaultCenter().addObserver(self, selector: "playerWillOpen:", name: "PlayerWillOpen", object: nil)
func playerWillOpen(notification: NSNotification) {
print("A Player will be opened now")
}
更好的通知注入
由于 AVPlayerView 不会被删除而只会被释放，我们将不得不稍微重写我们的代码并向 AVPlayerViewController 注入一些通知。这样我们就可以收到任意多的通知，例如：PlayerWillAppear 和 PlayerWillDisappear:
let originalViewWillAppearMethod = class_getInstanceMethod(UIViewController.self, "viewWillAppear:")
let originalViewWillAppearImplementation = method_getImplementation(originalViewWillAppearMethod)
typealias ViewWillAppearCFunction = @convention(c) (UIViewController, Selector, Bool) -> Void
let castedOriginalViewWillAppearImplementation = unsafeBitCast(originalViewWillAppearImplementation, ViewWillAppearCFunction.self)
let newViewWillAppearImplementationBlock: @convention(block) (UIViewController!, Bool) -> Void = { (viewController: UIViewController!, animated: Bool) -> Void in
castedOriginalViewWillAppearImplementation(viewController, "viewWillAppear:", animated)
if viewController is AVPlayerViewController {
NSNotificationCenter.defaultCenter().postNotificationName("PlayerWillAppear", object: nil)
}
}
let newViewWillAppearImplementation = imp_implementationWithBlock(unsafeBitCast(newViewWillAppearImplementationBlock, AnyObject.self))
method_setImplementation(originalViewWillAppearMethod, newViewWillAppearImplementation)
let originalViewWillDisappearMethod = class_getInstanceMethod(UIViewController.self, "viewWillDisappear:")
let originalViewWillDisappearImplementation = method_getImplementation(originalViewWillDisappearMethod)
typealias ViewWillDisappearCFunction = @convention(c) (UIViewController, Selector, Bool) -> Void
let castedOriginalViewWillDisappearImplementation = unsafeBitCast(originalViewWillDisappearImplementation, ViewWillDisappearCFunction.self)
let newViewWillDisappearImplementationBlock: @convention(block) (UIViewController!, Bool) -> Void = { (viewController: UIViewController!, animated: Bool) -> Void in
castedOriginalViewWillDisappearImplementation(viewController, "viewWillDisappear:", animated)
if viewController is AVPlayerViewController {
NSNotificationCenter.defaultCenter().postNotificationName("PlayerWillDisappear", object: nil)
}
}
let newViewWillDisappearImplementation = imp_implementationWithBlock(unsafeBitCast(newViewWillDisappearImplementationBlock, AnyObject.self))
method_setImplementation(originalViewWillDisappearMethod, newViewWillDisappearImplementation)
现在我们可以观察到这两个通知，一切顺利：
NSNotificationCenter.defaultCenter().addObserver(self, selector: "playerWillAppear:", name: "PlayerWillAppear", object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "playerWillDisappear:", name: "PlayerWillDisappear", object: nil)
func playerWillAppear(notification: NSNotification) {
print("A Player will be opened now")
}
func playerWillDisappear(notification: NSNotification) {
print("A Player will be closed now")
}
URL
我花了几个小时挖掘一些 iOS 运行时 Headers 来猜测我在哪里可以找到指向视频的 URL，但我无法找到它.当我深入研究 WebKit 本身的一些源文件时，我不得不放弃并接受没有 简单的方法 来做到这一点，虽然我相信它隐藏在某个地方并且可以到达，但是很可能需要付出很多努力。
我尝试将一些用户脚本添加（注入）到 WKWebView，这种方式比方法混合更安全：
相关代码如下：
let contentController = WKUserContentController()
if let jsSource = NSBundle.mainBundle().URLForResource("video_play_messenger", withExtension: "js"),
let jsSourceString = try? String(contentsOfURL: jsSource) {
let userScript = WKUserScript(source: jsSourceString, injectionTime: .AtDocumentEnd, forMainFrameOnly: true)
contentController.addUserScript(userScript)
contentController.addScriptMessageHandler(self, name: "callbackHandler")
}
let webConfiguration = WKWebViewConfiguration()
webConfiguration.userContentController = contentController
webView = WKWebView(frame: CGRect.zero, configuration: webConfiguration)
let request = NSURLRequest(URL: NSURL(string: "URL_FOR_VIDEO")!)
webView.loadRequest(request)
对于WKWebView的controller，符合WKScriptMessageHandler实现这个方法：
func userContentController(userContentController: WKUserContentController, didReceiveScriptMessage message: WKScriptMessage) {
if message.name == "callbackHandler" {
if let messageString = message.body as? String where messageString == "VideoIsPlaying" {
// Vide is being played
}
}
}
将 video_play_messenger.js 添加到您的项目：
function videoTags() {
return document.getElementsByTagName("video");
}
function setupVideoPlayingHandler() {
try {
var videos = videoTags()
for (var i = 0; i < videos.length; i++) {
videos.item(i).onplaying = function() {
webkit.messageHandlers.callbackHandler.postMessage("VideoIsPlaying");
}
}
} catch (error) {
console.log(error);
}
}
function setupVidePlayingListener() {
// If we have video tags, setup onplaying handler
if (videoTags().length > 0) {
setupVideoPlayingHandler();
return
}
// Otherwise, wait for 100ms and check again.
setTimeout(setupVidePlayingListener, 100);
}
setupVidePlayingListener();
参考：http://www.kinderas.com/technology/2014/6/15/wkwebview-and-javascript-in-ios-8-using-swift