WKWebView的使用

注意： #import <WebKit/WebKit.h>
//初始化
_webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT) configuration:config];
// UI代理
_webView.UIDelegate = self;
// 导航代理
_webView.navigationDelegate = self;
// 是否允许手势左滑返回上一级, 类似导航控制的左滑返回
_webView.allowsBackForwardNavigationGestures = YES;
//可返回的页面列表, 存储已打开过的网页 
WKBackForwardList * backForwardList = [_webView backForwardList];

//NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"https://www.baidu.com"]];
//[request addValue:[self readCurrentCookieWithDomain:@"https://www.baidu.com"] forHTTPHeaderField:@"Cookie"];
//[_webView loadRequest:request];

//页面后退
[_webView goBack];
//页面前进
[_webView goForward];
//刷新当前页面
[_webView reload];
        
NSString *path = [[NSBundle mainBundle] pathForResource:@"Demo.html" ofType:nil];
NSString *htmlString = [[NSString alloc]initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
//加载本地html文件
[_webView loadHTMLString:htmlString baseURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] bundlePath]]];
        

//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];
//注册一个name为jsToOc的js方法
[wkUController addScriptMessageHandler:weakScriptMessageDelegate  name:@"jsToOc"];

[wkUController addScriptMessageHandler:weakScriptMessageDelegate  name:@"jsToOcWithPrams"]; 
config.userContentController = wkUController;
        

//以下代码适配文本大小，由UIWebView换为WKWebView后，会发现字体小了很多，这应该是WKWebView与html的兼容问题，解决办法是修改原网页，要么我们手动注入JS
NSString *jSString = @"var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width'); document.getElementsByTagName('head')[0].appendChild(meta);";

//用于进行JavaScript注入
WKUserScript *wkUScript = [[WKUserScript alloc] initWithSource:jSString injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];
[config.userContentController addUserScript:wkUScript];

// 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 = @"xxxxx";
    if([urlStr hasPrefix:htmlHeadString]){
        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"通过截取URL调用OC" message:@"你想前往xxxxx页面?" 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];
            [[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:@"zhangsan" password:@"666" 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{

}

 /**
     *  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;
}

//添加监测网页加载进度的观察者
[self.webView addObserver:self
              forKeyPath:@"estimatedProgress"
              options:0
              context:nil];

//添加监测网页标题title的观察者
[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];
    }
}
    //移除观察者
    [_webView removeObserver:self
                  forKeyPath:NSStringFromSelector(@selector(estimatedProgress))];
    [_webView removeObserver:self
                  forKeyPath:NSStringFromSelector(@selector(title))];

//这个类主要用来做native与JavaScript的交互管理
WKUserContentController * wkUController = [[WKUserContentController alloc] init];
//注册一个name为jsToOcNoPrams的js方法，设置处理接收JS方法的代理
[wkUController addScriptMessageHandler:self  name:@"jsToOc"];
[wkUController addScriptMessageHandler:self  name:@"jsToOcWithPrams"];
config.userContentController = wkUController;

注意：遵守WKScriptMessageHandler协议，代理是由WKUserContentControl设置

//通过接收JS传出消息的name进行捕捉的回调方法  js调OC
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
    NSLog(@"name:%@\\\\n body:%@\\\\n frameInfo:%@\\\\n",message.name,message.body,message.frameInfo);
}

//OC调用JS  changeColor()是JS方法名，completionHandler是异步回调block
NSString *jsString = [NSString stringWithFormat:@"changeColor('%@')", @"传入参数"];
[_webView evaluateJavaScript:jsString completionHandler:^(id _Nullable data, NSError * _Nullable error) {
   NSLog(@"改变HTML的背景色");
}];
    
//改变字体大小 调用原生JS方法
NSString *jsFont = [NSString stringWithFormat:@"document.getElementsByTagName('body')[0].style.webkitTextSizeAdjust= '%d%%'", arc4random()%99 + 100];
[_webView evaluateJavaScript:jsFont completionHandler:nil];