WebKit

设置 WKWebViewConfiguration 配置WKWebView的属性。

self.webView = [[WKWebView alloc] initWithFrame: self.view.bounds configuration:config];
// 通过JS与webview内容交互

// 通过JS与webview内容交互

 config.userContentController = [[WKUserContentController alloc] init];

  // 注入JS对象名称AppModel，当JS通过AppModel来调用时，
  // 我们可以在WKScriptMessageHandler代理中接收到
  
 [config.userContentController addScriptMessageHandler: self name: @"AppModel"];

  // 导航代理
  self.webView.navigationDelegate = self;
  // 与webview UI交互代理
  self.webView.UIDelegate = self;
  
  // 添加KVO监听
  [self.webView addObserver:self
                 forKeyPath:@"loading"
                    options:NSKeyValueObservingOptionNew
                    context:nil];
  [self.webView addObserver:self
                 forKeyPath:@"title"
                    options:NSKeyValueObservingOptionNew
                    context:nil];
  [self.webView addObserver:self
                 forKeyPath:@"estimatedProgress"
                    options:NSKeyValueObservingOptionNew
                    context:nil];

pragma mark - WKScriptMessageHandler

- (void)userContentController:(WKUserContentController *)userContentController
      didReceiveScriptMessage:(WKScriptMessage *)message {
  if ([message.name isEqualToString:@"AppModel"]) {
    // 打印所传过来的参数，只支持NSNumber, NSString, NSDate, NSArray,
    // NSDictionary, and NSNull类型
    NSLog(@"%@", message.body);
  }
}

pragma mark - KVO

- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary<NSString *,id> *)change
                       context:(void *)context {
  if ([keyPath isEqualToString:@"loading"]) {
    NSLog(@"loading");
  } else if ([keyPath isEqualToString:@"title"]) {
    self.title = self.webView.title;
  } else if ([keyPath isEqualToString:@"estimatedProgress"]) {
    NSLog(@"progress: %f", self.webView.estimatedProgress);
    self.progressView.progress = self.webView.estimatedProgress;
  }
  
  // 加载完成
  if (!self.webView.loading) {
    // 手动调用JS代码
    // 每次页面完成都弹出来，大家可以在测试时再打开
    NSString *js = @"callJsAlert()";
    [self.webView evaluateJavaScript:js completionHandler:^(id _Nullable response, NSError * _Nullable error) {
      NSLog(@"response: %@ error: %@", response, error);
      NSLog(@"call js alert by native");
    }];
    
    [UIView animateWithDuration:0.5 animations:^{
      self.progressView.alpha = 0;
    }];
  }
}