在iOS 8中使用WKWebView,我如何从本地端运行JavaScript函数或者以其他方式从本地端向JavaScript通信?似乎没有类似于UIWebView的stringByEvaluatingJavaScriptFromString:
的方法。
(我可以在configuration.userContentController
对象上使用- addScriptMessageHandler:name:
来允许JS向本地进行通信,但我正在寻找反向通信。)
在iOS 8中使用WKWebView,我如何从本地端运行JavaScript函数或者以其他方式从本地端向JavaScript通信?似乎没有类似于UIWebView的stringByEvaluatingJavaScriptFromString:
的方法。
(我可以在configuration.userContentController
对象上使用- addScriptMessageHandler:name:
来允许JS向本地进行通信,但我正在寻找反向通信。)
我在这里提问后不久就为此提交了一个Radar。
几天前刚刚添加了一种新的方法(感谢jcesarmobile指出):
添加
-[WKWebView evaluateJavaScript:completionHandler:]
http://trac.webkit.org/changeset/169765
该方法可在iOS 8 beta 3及以上版本中使用。以下是新方法的签名:
/* @abstract Evaluates the given JavaScript string.
@param javaScriptString The JavaScript string to evaluate.
@param completionHandler A block to invoke when script evaluation completes
or fails.
@discussion The completionHandler is passed the result of the script evaluation
or an error.
*/
- (void)evaluateJavaScript:(NSString *)javaScriptString
completionHandler:(void (^)(id, NSError *))completionHandler;
文档在这里可用: https://developer.apple.com/documentation/webkit/wkwebview/1415017-evaluatejavascript.
let preferences = WKPreferences() preferences.javaScriptEnabled = true let configuration = WKWebViewConfiguration() configuration.preferences = preferences webView = WKWebView(frame: .zero, configuration: configuration)
- wildcat12该脚本将被插入到WKWebView中显示的页面中。此脚本将返回页面URL(但您可以编写另一段JavaScript代码)。这意味着脚本事件在网页上生成,但将在我们的函数中处理:
func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {...}
extension WKUserScript {
enum Defined: String {
case getUrlAtDocumentStartScript = "GetUrlAtDocumentStart"
case getUrlAtDocumentEndScript = "GetUrlAtDocumentEnd"
var name: String { return rawValue }
private var injectionTime: WKUserScriptInjectionTime {
switch self {
case .getUrlAtDocumentStartScript: return .atDocumentStart
case .getUrlAtDocumentEndScript: return .atDocumentEnd
}
}
private var forMainFrameOnly: Bool {
switch self {
case .getUrlAtDocumentStartScript: return false
case .getUrlAtDocumentEndScript: return false
}
}
private var source: String {
switch self {
case .getUrlAtDocumentEndScript, .getUrlAtDocumentStartScript:
return "webkit.messageHandlers.\(name).postMessage(document.URL)"
}
}
fileprivate func create() -> WKUserScript {
return WKUserScript(source: source,
injectionTime: injectionTime,
forMainFrameOnly: forMainFrameOnly)
}
}
}
extension WKWebViewConfiguration {
func add(script: WKUserScript.Defined, scriptMessageHandler: WKScriptMessageHandler) {
userContentController.addUserScript(script.create())
userContentController.add(scriptMessageHandler, name: script.name)
}
}
初始化WKWebView
let config = WKWebViewConfiguration()
config.add(script: .getUrlAtDocumentStartScript, scriptMessageHandler: self)
config.add(script: .getUrlAtDocumentEndScript, scriptMessageHandler: self)
webView = WKWebView(frame: UIScreen.main.bounds, configuration: config)
webView.navigationDelegate = self
view.addSubview(webView)
捕获事件
extension ViewController: WKScriptMessageHandler {
func userContentController (_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
if let script = WKUserScript.Defined(rawValue: message.name),
let url = message.webView?.url {
switch script {
case .getUrlAtDocumentStartScript: print("start: \(url)")
case .getUrlAtDocumentEndScript: print("end: \(url)")
}
}
}
}
import UIKit
import WebKit
class ViewController: UIViewController, WKNavigationDelegate {
private var webView = WKWebView()
override func viewDidLoad() {
super.viewDidLoad()
let config = WKWebViewConfiguration()
config.add(script: .getUrlAtDocumentStartScript, scriptMessageHandler: self)
config.add(script: .getUrlAtDocumentEndScript, scriptMessageHandler: self)
webView = WKWebView(frame: UIScreen.main.bounds, configuration: config)
webView.navigationDelegate = self
view.addSubview(webView)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
webView.load(urlString: "http://apple.com")
}
}
extension ViewController: WKScriptMessageHandler {
func userContentController (_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
if let script = WKUserScript.Defined(rawValue: message.name),
let url = message.webView?.url {
switch script {
case .getUrlAtDocumentStartScript: print("start: \(url)")
case .getUrlAtDocumentEndScript: print("end: \(url)")
}
}
}
}
extension WKWebView {
func load(urlString: String) {
if let url = URL(string: urlString) {
load(URLRequest(url: url))
}
}
}
extension WKUserScript {
enum Defined: String {
case getUrlAtDocumentStartScript = "GetUrlAtDocumentStart"
case getUrlAtDocumentEndScript = "GetUrlAtDocumentEnd"
var name: String { return rawValue }
private var injectionTime: WKUserScriptInjectionTime {
switch self {
case .getUrlAtDocumentStartScript: return .atDocumentStart
case .getUrlAtDocumentEndScript: return .atDocumentEnd
}
}
private var forMainFrameOnly: Bool {
switch self {
case .getUrlAtDocumentStartScript: return false
case .getUrlAtDocumentEndScript: return false
}
}
private var source: String {
switch self {
case .getUrlAtDocumentEndScript, .getUrlAtDocumentStartScript:
return "webkit.messageHandlers.\(name).postMessage(document.URL)"
}
}
fileprivate func create() -> WKUserScript {
return WKUserScript(source: source,
injectionTime: injectionTime,
forMainFrameOnly: forMainFrameOnly)
}
}
}
extension WKWebViewConfiguration {
func add(script: WKUserScript.Defined, scriptMessageHandler: WKScriptMessageHandler) {
userContentController.addUserScript(script.create())
userContentController.add(scriptMessageHandler, name: script.name)
}
}
在您的Info.plist中添加传输安全设置
<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>
addScript
不再是 WKWebViewConfiguration
的方法了吗? - Firo这可能不是最理想的方法,但根据您的使用情况,在感染用户脚本后,您可以重新加载WKWebView:
NSString *scriptSource = @"alert('WKWebView JS Call!')";
WKUserScript *userScript = [[WKUserScript alloc] initWithSource:scriptSource
injectionTime:WKUserScriptInjectionTimeAtDocumentEnd
forMainFrameOnly:YES];
[wkWebView.configuration.userContentController addUserScript:userScript];
[wkWebView reload];
extension WKWebView {
func runJavaScriptInMainFrame(#scriptString: NSString) -> Void {
let selector : Selector = "_runJavaScriptInMainFrame:"
let invocation = NSInvocationOperation(target: self, selector: selector, object: scriptString)
NSOperationQueue.mainQueue().addOperation(invocation)
}
}
使用时,请调用:
webview.runJavacriptInMainFrame:(scriptString: "some javascript code")
我刚刚开始研究WKWebView API,所以这可能不是最好的方法,但我认为您可以使用以下代码完成:
NSString *scriptSource = @"console.log('Hi this is in JavaScript');";
WKUserScript *userScript = [[WKUserScript alloc]
initWithSource:scriptSource
injectionTime:WKUserScriptInjectionTimeAtDocumentStart
forMainFrameOnly:YES];
[myWKController addUserScript:userScript];
这是一个运行JS代码以从base64字符串加载.pdf文件的方法示例。
private func setData(_ base64String: String) {
webView.evaluateJavaScript(
"externalInterfaceLoadBase64('\(base64String)', scale = 1.0)",
completionHandler: { _, error in
if let error = error {
debugPrint("Evaluating JavaScript error: \(error)")
}
}
)
}
webView.loadRequest(NSURLRequest(URL: NSURL(string: "javascript:alert(1)")))
,但好像什么都没有发生。 - Sophie Alpert