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iOS13 WKWebView使用与UIWebView的差异和坑

iOS13 WKWebView使用与UIWebView的差异和坑

作者: tdb云端 | 来源:发表于2020-04-02 16:26 被阅读0次

    1.WKWebView内存不释放的问题。

    // WKWebView 内存不释放的问题解决
    @interface WeakWebViewScriptMessageDelegate : NSObject<WKScriptMessageHandler>
    
    //WKScriptMessageHandler 这个协议类专门用来处理JavaScript调用原生OC的方法
    @property (nonatomic, weak) id<WKScriptMessageHandler> scriptDelegate;
    
    - (instancetype)initWithDelegate:(id<WKScriptMessageHandler>)scriptDelegate;
    
    @end
    @implementation WeakWebViewScriptMessageDelegate
    
    - (instancetype)initWithDelegate:(id<WKScriptMessageHandler>)scriptDelegate {
        self = [super init];
        if (self) {
            _scriptDelegate = scriptDelegate;
        }
        return self;
    }
    
    #pragma mark - WKScriptMessageHandler
    //遵循WKScriptMessageHandler协议,必须实现如下方法,然后把方法向外传递
    //通过接收JS传出消息的name进行捕捉的回调方法
    - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message {
        
        if ([self.scriptDelegate respondsToSelector:@selector(userContentController:didReceiveScriptMessage:)]) {
            [self.scriptDelegate userContentController:userContentController didReceiveScriptMessage:message];
        }
    }
    
    @end
    

    2.创建网页配置对象。

            //创建网页配置对象
            WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];
            
            // 创建设置对象
            WKPreferences *preference = [[WKPreferences alloc]init];
            //最小字体大小 当将javaScriptEnabled属性设置为NO时,可以看到明显的效果
            preference.minimumFontSize = 0;
            //设置是否支持javaScript 默认是支持的
            preference.javaScriptEnabled = YES;
            // 在iOS上默认为NO,表示是否允许不经过用户交互由javaScript自动打开窗口
            preference.javaScriptCanOpenWindowsAutomatically = YES;
            config.preferences = preference;
            
            // 是使用h5的视频播放器在线播放, 还是使用原生播放器全屏播放
            config.allowsInlineMediaPlayback = YES;
            //设置视频是否需要用户手动播放  设置为NO则会允许自动播放
            config.requiresUserActionForMediaPlayback = YES;
            //设置是否允许画中画技术 在特定设备上有效
            config.allowsPictureInPictureMediaPlayback = YES;
            //设置请求的User-Agent信息中应用程序名称 iOS9后可用
            config.applicationNameForUserAgent = @"ChinaDailyForiPad";
            
            //自定义的WKScriptMessageHandler 是为了解决内存不释放的问题
            WeakWebViewScriptMessageDelegate *weakScriptMessageDelegate = [[WeakWebViewScriptMessageDelegate alloc] initWithDelegate:self];
            //这个类主要用来做native与JavaScript的交互管理
            WKUserContentController * wkUController = [[WKUserContentController alloc] init];
            config.userContentController = wkUController;
    
    注册一个name为jsToOcNoPrams的js方法 设置处理接收JS方法的对象。
    [wkUController addScriptMessageHandler:weakScriptMessageDelegate  name:@"jsToOcNoPrams"];
    
    
    通过接收JS传出消息的name进行捕捉的回调方法。
    - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
        NSLog(@"name:%@\\\\n body:%@\\\\n frameInfo:%@\\\\n",message.name,message.body,message.frameInfo);
        //用message.body获得JS传出的参数体
        NSDictionary * parameter = message.body;
        //JS调用OC
        if([message.name isEqualToString:@"jsToOcNoPrams"]){
            UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"js调用到了oc" message:@"不带参数" preferredStyle:UIAlertControllerStyleAlert];
            [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            }])];
            [self presentViewController:alertController animated:YES completion:nil];
            
        }else if([message.name isEqualToString:@"jsToOcWithPrams"]){
            UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"js调用到了oc" message:parameter[@"params"] preferredStyle:UIAlertControllerStyleAlert];
            [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            }])];
            [self presentViewController:alertController animated:YES completion:nil];
        }
    }
    

    3.WKNavigationDelegate,主要处理一些跳转、加载处理操作。

    // 页面开始加载时调用
    - (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation {
    }
    
    // 页面加载失败时调用
    - (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error {
        [self.progressView setProgress:0.0f animated:NO];
    }
    
    // 当内容开始返回时调用
    - (void)webView:(WKWebView *)webView didCommitNavigation:(WKNavigation *)navigation {
        
    }
    
    // 页面加载完成之后调用
    - (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation {
        [self getCookie];
    }
    
    //提交发生错误时调用
    - (void)webView:(WKWebView *)webView didFailNavigation:(WKNavigation *)navigation withError:(NSError *)error {
        [self.progressView setProgress:0.0f animated:NO];
    }
    
    // 接收到服务器跳转请求即服务重定向时之后调用
    - (void)webView:(WKWebView *)webView didReceiveServerRedirectForProvisionalNavigation:(WKNavigation *)navigation {
        
    }
    
    // 根据WebView对于即将跳转的HTTP请求头信息和相关信息来决定是否跳转
    - (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
        
        NSString * urlStr = navigationAction.request.URL.absoluteString;
        NSLog(@"发送跳转请求:%@",urlStr);
        //自己定义的协议头
        NSString *htmlHeadString = @"github://";
        if([urlStr hasPrefix:htmlHeadString]){
            UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"通过截取URL调用OC" message:@"你想前往我的Github主页?" preferredStyle:UIAlertControllerStyleAlert];
            [alertController addAction:([UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
                
            }])];
            [alertController addAction:([UIAlertAction actionWithTitle:@"打开" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
                NSURL * url = [NSURL URLWithString:[urlStr stringByReplacingOccurrencesOfString:@"github://callName_?" withString:@""]];
                [[UIApplication sharedApplication] openURL:url];
                
            }])];
            [self presentViewController:alertController animated:YES completion:nil];
            
            decisionHandler(WKNavigationActionPolicyCancel);
            
        }else{
            decisionHandler(WKNavigationActionPolicyAllow);
        }
        
        
    }
    
    // 根据客户端受到的服务器响应头以及response相关信息来决定是否可以跳转
    - (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler{
        NSString * urlStr = navigationResponse.response.URL.absoluteString;
        NSLog(@"当前跳转地址:%@",urlStr);
        //允许跳转
        decisionHandler(WKNavigationResponsePolicyAllow);
        //不允许跳转
        //decisionHandler(WKNavigationResponsePolicyCancel);
    }
    
    //需要响应身份验证时调用 同样在block中需要传入用户身份凭证
    - (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential * _Nullable credential))completionHandler{
        
        //用户身份信息
        NSURLCredential * newCred = [[NSURLCredential alloc] initWithUser:@"user123" password:@"123" persistence:NSURLCredentialPersistenceNone];
        //为 challenge 的发送方提供 credential
        [challenge.sender useCredential:newCred forAuthenticationChallenge:challenge];
        completionHandler(NSURLSessionAuthChallengeUseCredential,newCred);
        
    }
    
    //进程被终止时调用
    - (void)webViewWebContentProcessDidTerminate:(WKWebView *)webView{
    
    }
    

    4.WKUIDelegate 要处理JS脚本,确认框,警告框等

    /**
     *  web界面中有弹出警告框时调用
     *
     *  @param webView           实现该代理的webview
     *  @param message           警告框中的内容
     *  @param completionHandler 警告框消失调用
     */
    - (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler {
        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"HTML的弹出框" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];
        [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            completionHandler();
        }])];
        [self presentViewController:alertController animated:YES completion:nil];
    }
    // 确认框
    //JavaScript调用confirm方法后回调的方法 confirm是js中的确定框,需要在block中把用户选择的情况传递进去
    - (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL))completionHandler{
        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];
        [alertController addAction:([UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
            completionHandler(NO);
        }])];
        [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            completionHandler(YES);
        }])];
        [self presentViewController:alertController animated:YES completion:nil];
    }
    // 输入框
    //JavaScript调用prompt方法后回调的方法 prompt是js中的输入框 需要在block中把用户输入的信息传入
    - (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable))completionHandler{
        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:prompt message:@"" preferredStyle:UIAlertControllerStyleAlert];
        [alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
            textField.text = defaultText;
        }];
        [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            completionHandler(alertController.textFields[0].text?:@"");
        }])];
        [self presentViewController:alertController animated:YES completion:nil];
    }
    // 页面是弹出窗口 _blank 处理
    - (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures {
        if (!navigationAction.targetFrame.isMainFrame) {
            [webView loadRequest:navigationAction.request];
        }
        return nil;
    }
    

    5.添加监测网页加载进度的观察者

        - (void)viewDidLoad {
        [super viewDidLoad];
        [self.view addSubview:self.webView];
        [self.view addSubview:self.progressView];
        //添加监测网页加载进度的观察者
        [self.webView addObserver:self
                       forKeyPath:NSStringFromSelector(@selector(estimatedProgress))
                          options:0
                          context:nil];
        [self.webView addObserver:self
                       forKeyPath:@"title"
                          options:NSKeyValueObservingOptionNew
                          context:nil];
    }
    
    //kvo 监听进度 必须实现此方法
    -(void)observeValueForKeyPath:(NSString *)keyPath
                         ofObject:(id)object
                           change:(NSDictionary<NSKeyValueChangeKey,id> *)change
                          context:(void *)context{
        
        if ([keyPath isEqualToString:NSStringFromSelector(@selector(estimatedProgress))]
            && object == _webView) {
            
            NSLog(@"网页加载进度 = %f",_webView.estimatedProgress);
            self.progressView.progress = _webView.estimatedProgress;
            if (_webView.estimatedProgress >= 1.0f) {
                dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                    self.progressView.progress = 0;
                });
            }
            
        }else if([keyPath isEqualToString:@"title"]
                 && object == _webView){
            self.navigationItem.title = _webView.title;
        }else{
            [super observeValueForKeyPath:keyPath
                                 ofObject:object
                                   change:change
                                  context:context];
        }
    }
    
    #pragma mark - Getter
    - (UIProgressView *)progressView {
        if (!_progressView){
            _progressView = [[UIProgressView alloc] initWithFrame:CGRectMake(0, StatusBarAndNavigationBarHeight + 2, self.view.frame.size.width, 2)];
            _progressView.tintColor = [UIColor blueColor];
            _progressView.trackTintColor = [UIColor clearColor];
        }
        return _progressView;
    }
    

    6 OC调用JS方法

    #pragma mark 登录成功回调JS(H5传值) (fromNativeLoginSuccess 与JS统一声明的方法名)
    - (void)loginSuccess {
        [self OcToJs:[NSString stringWithFormat:@"fromNativeLoginSuccess('%@')",[self convertToJsonData]]];
    }
    

    7.JS调用OC方法。前提JS代码必须这样写(window.webkit.messageHandlers.<name>.postMessage(<messageBody>) )与UIWebView写法(window.<name>(<messageBody>) )不同。

    前提履行代理方法WKScriptMessageHandler,和方法名定义的一致才能收到JS的回调。
    - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
        NSLog(@"name:%@\\\\n body:%@\\\\n frameInfo:%@\\\\n",message.name,message.body,message.frameInfo);
        //用message.body获得JS传出的参数体
        NSDictionary * parameter = message.body;
        //JS调用OC
        if([message.name isEqualToString:@"jsToOcNoPrams"]){
            UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"js调用到了oc" message:@"不带参数" preferredStyle:UIAlertControllerStyleAlert];
            [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            }])];
            [self presentViewController:alertController animated:YES completion:nil];
            
        }else if([message.name isEqualToString:@"jsToOcWithPrams"]){
            UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"js调用到了oc" message:parameter[@"params"] preferredStyle:UIAlertControllerStyleAlert];
            [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            }])];
            [self presentViewController:alertController animated:YES completion:nil];
        }
    }
    

    8.移除JS方法

    - (void)dealloc{
        //移除注册的js方法
        [[_webView configuration].userContentController removeScriptMessageHandlerForName:@"jsToOcNoPrams"];
        [[_webView configuration].userContentController removeScriptMessageHandlerForName:@"jsToOcWithPrams"];
        //移除观察者
        [_webView removeObserver:self
                      forKeyPath:NSStringFromSelector(@selector(estimatedProgress))];
        [_webView removeObserver:self
                      forKeyPath:NSStringFromSelector(@selector(title))];
       // 移除所有注册js方法
       [[_webView configuration].userContentController removeAllUserScripts];
    }
    

    9.WKWebView 注册脚本方法,兼容之前项目中使用UIWebView

    1.UIWebView js编码是window.prompt()
    2.WKWebVIew js编码window.webkit.messageHandlers.(name).postMessage()
    iOS13弃用UIWebView。换成WKWebVIew,js编码方法更改。之前用的JavaScriptCore (JSContext)已不能用,为了保证安卓端和H5端不更改项目源码,兼容老版本,采取了脚本转换的方法。
    1.注入本地js脚本, 使js和native交互方法统一。

        NSString *jsSource = [NSString stringWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"ios_brige" ofType:@"js"] encoding:NSUTF8StringEncoding error:nil];
        WKUserScript *script = [[WKUserScript alloc] initWithSource:jsSource injectionTime:WKUserScriptInjectionTimeAtDocumentStart forMainFrameOnly:YES];
        [config.userContentController addUserScript:script];
    

    2.WKScriptMessageHandler,JS回调统一处理。

    // WKScriptMessageHandler
    - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message {
        NSLog(@"name:%@---body:%@",message.name,message.body);
        //用message.body获得JS传出的参数体
        NSString * parameter = message.body;
        NSData *jsonData = [parameter dataUsingEncoding:NSUTF8StringEncoding];
        NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:nil];
        
        NSString *method = dic[@"method"];
        NSString *param = dic[@"params"];
        if (param) {
            method = [method stringByAppendingString:@":"];
        }
        SEL sel = NSSelectorFromString(method);
        if ([self respondsToSelector:sel]) {
            [self performSelectorOnMainThread:sel withObject:param waitUntilDone:YES];
        }else{
            NSLog(@"webview not find method %@",method);
        }
    }
    

    3.本地JS代码如下处理

    function calliOSFunction(namespace, functionName, args, callback) {
        if (!window.webkit.messageHandlers[namespace]) return;
        var wrap = {
            "method": functionName,
            "params": args
        };
        window.webkit.messageHandlers[namespace].postMessage(JSON.stringify(wrap));
    }
    
    var jsCallNative = {};
    
    //无返回值方法转换
    //会将jsCallNative.toLogin()的调用方式,转换成window.webkit.messageHandlers.jsCallNative.postMessage()
    jsCallNative.nativeClosePage = function () {
        calliOSFunction("ShowSnappedUpObj","nativeClosePage");
    }
    //有返回值方法转换
    jsCallNative.nativeShowHud = function (infoStr) {
        calliOSFunction("ShowSnappedUpObj","nativeShowHud",infoStr);
    }
    
    //有返回值方法转换
    //会将jsCallNative.getSign()的调用方式,转换成window.prompt()
    jsCallNative.getSign = function () {
        var result = window.prompt("getSign");
        return result;
    }
    
    jsCallNative.appendABCwithString = function (str) {
        var result = window.prompt("appendABCwithString",str);
        return result;
    }
    
    jsCallNative.isLogin = function () {
        var result = window.prompt("isLogin");
        return result;
    }
    
    window["ShowSnappedUpObj"] = jsCallNative;
    

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