簡單說說iOS之WKWebView的用法小結

<h2 >歡迎來到JS世界</h2>

 <p > <a href="github://callName_?https://github.com/wslcmk" rel="external nofollow" >Github主頁</a> ：截獲URL調用OC</p>

<p > <a  rel="external nofollow" >GitLab主頁</a> </p>
<p > <button id="btn1" type = "button" onclick = "jsToOcFunctionOne()" > JS調用OC->不帶參數 </button> </p>

<p > <button id="btn2" type = "button" onclick = "jsToOcFunctionTwo()"> JS調用OC->帶參數 </button> </p>


<p > <button id="btn3" type = "button" onclick = "showAlert()" > oc捕獲到html的彈出框 </button> </p>

<!--    JS語法-->
<script type = "text/javascript">
  
function jsToOcFunctionOne()
{
  window.webkit.messageHandlers.jsToOcNoPrams.postMessage({});
}

function jsToOcFunctionTwo()
{
  window.webkit.messageHandlers.jsToOcWithPrams.postMessage({"params":"我是JS參數"});
}

function showAlert()
{
  alert("我來自JS世界，被你發現了");
}

//改變背景色
function changeBgColor()
{
  document.body.style.backgroundColor = randomColor();
}

//  KVO監聽：獲取進度并顯示 獲取標題并顯示
  [self.webView addObserver:self forKeyPath:@"estimatedProgress" options:NSKeyValueObservingOptionNew context:nil];
  [self.webView addObserver:self forKeyPath:@"title" options:NSKeyValueObservingOptionNew context:nil];

#pragma mark - KVO
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context
{
  if ([keyPath isEqualToString:@"title"]&&object == _webView) {
    self.title = _webView.title;
  }else if ([keyPath isEqualToString:@"estimatedProgress"]
       && object == _webView)
  {
    self.progressView.progress = _webView.estimatedProgress;
    if (_webView.estimatedProgress >= 1.0f) {
      dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(1 * NSEC_PER_SEC)),
             dispatch_get_main_queue(), ^{
               self.progressView.progress = 0;
             });
    }
  }
}

#pragma mark -- WKNavigationDelegate  WKNavigationDelegate主要處理一些跳轉、加載處理操作
// 根據WebView對于即將跳轉的HTTP請求頭信息和相關信息來決定是否跳轉
- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
  
  NSString * urlStr = navigationAction.request.URL.absoluteString;
  NSLog(@"發送跳轉請求：%@",urlStr);
  //自己定義的協議頭
  NSString *htmlHeadString = @"github://";
  if([urlStr hasPrefix:htmlHeadString]){
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"通過截取URL調用OC" message:@"前往Github?" preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:([UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {
      
    }])];
    [alertController addAction:([UIAlertAction actionWithTitle:@"打開" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
      NSURL * url = [NSURL URLWithString:[urlStr stringByReplacingOccurrencesOfString:@"github://callName_?" withString:@""]];
      [[UIApplication sharedApplication]canOpenURL:url];
    }])];
    [self presentViewController:alertController animated:YES completion:nil];
    decisionHandler(WKNavigationActionPolicyCancel);
  }else{
    decisionHandler(WKNavigationActionPolicyAllow);
  }
}

#pragma mark -- WKUIDelegate WKUIDelegate主要處理JS腳本，確認框，警告框等
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler {
  UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"JS-alert-Action" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];
  [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
    completionHandler();
  }])];
  [self presentViewController:alertController animated:YES completion:nil];
}

#pragma mark -navigationItem Action
- (void)ocToJs
{
  // changeColor()是JS方法名
  NSString *jsString = [NSString stringWithFormat:@"changeBgColor()"];
  [_webView evaluateJavaScript:jsString completionHandler:^(id _Nullable data, NSError * _Nullable error) {
    
  }];
}

//創建網頁配置對象
    WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];
    WKUserContentController * wkUController = [[WKUserContentController alloc] init];
    //注冊一個name為jsToOcNoPrams的js方法 設置處理接收JS方法的對象
    [wkUController addScriptMessageHandler:self name:@"jsToOcNoPrams"];
    [wkUController addScriptMessageHandler:self name:@"jsToOcWithPrams"];
    config.userContentController = wkUController;

#pragma mark - 通過接收JS傳出消息的name進行捕捉的回調方法
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{
  NSLog(@"name:%@\\\\n body:%@\\\\n frameInfo:%@\\\\n",message.name,message.body,message.frameInfo);
  //用message.body獲得JS傳出的參數體
  NSDictionary * parameter = message.body;
  //JS調用OC
  if([message.name isEqualToString:@"jsToOcNoPrams"]){
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"js調用到了oc" message:@"不帶參數" 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調用到了oc" message:parameter[@"params"] preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
    }])];
    [self presentViewController:alertController animated:YES completion:nil];
  }  
}