WKWebView的使用与JS交互详细解读

WKWebView * webviwe = [[WKWebView alloc]initWithFrame:self.view.bounds];
[webviwe loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://www.baidu.com"]]];
[self.view addSubview:webviwe];   

 // estimatedProgress  WKWebView 这个属性添加观察者
 [webviwe addObserver:self forKeyPath:@"estimatedProgress" options:NSKeyValueObservingOptionNew context:nil];    

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *,id> *)change context:(void *)context
{
    if (object == webviwe && [keyPath isEqualToString:@"estimatedProgress"] ) {
        // 这里就不写进度条了，把加载的进度打印出来，进度条可以自己加上去！
        CGFloat newProgress = [[change objectForKey:NSKeyValueChangeNewKey] floatValue];
        NSLog(@"%f",newProgress);  
    }
}

#pragma mark - WKNavigationDelegate
// 页面加载开始  Provisional临时的
-(void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation
{
    NSLog(@"页面开始加载");   
}
// 加载内容
-(void)webView:(WKWebView *)webView didCommitNavigation:(WKNavigation *)navigation
{
    NSLog(@"内容正在加载当中");
}
// 页面加载完成
-(void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation
{
    NSLog(@"页面加载完成");
}
//  页面加载失败
-(void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation withError:(NSError *)error
{
    NSLog(@"页面加载失败");
}
// 接收到服务器重新配置请求之后再执行
-(void)webView:(WKWebView *)webView didReceiveServerRedirectForProvisionalNavigation:(WKNavigation *)navigation
{
    
}
// API是根据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
{   
    NSURLRequest * request = navigationAction.request;
    NSLog(@"%@",request.URL.absoluteString);
    
    // 判断请求头是否是 https://www.baidu.com 如果是就不在请求加载跳转
    WKNavigationActionPolicy  actionPolicy = WKNavigationActionPolicyAllow;
    if ([request.URL.absoluteString hasPrefix:@"https://www.baidu.com"]) {
        
        actionPolicy = WKNavigationActionPolicyCancel;
        
    }
    // 必须这样执行，不然会崩
    decisionHandler(actionPolicy);
}
/**
 *   
 要是允许跳转，看下面的打印内容，注意加载的顺序！和下面的方法进行比较，区分它们的不同之处
 2016-08-11 13:55:12.628 RaectiveCocoaTest[18155:211964] https://www.baidu.com/
 2016-08-11 13:55:12.629 RaectiveCocoaTest[18155:211964] 页面开始加载
 2016-08-11 13:55:13.725 RaectiveCocoaTest[18155:211964] 内容正在加载当中
 2016-08-11 13:55:14.681 RaectiveCocoaTest[18155:211964] 页面加载完成
 *
 */
// API是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
{
    NSLog(@"%@",navigationResponse.response);
    /**
     *  判断响应的数据里面的URL是https://www.baidu.com/开头的，要是就不让它加载跳转
     */
    WKNavigationResponsePolicy responsePolicy = WKNavigationResponsePolicyAllow;
    if ([navigationResponse.response.URL.absoluteString hasPrefix:@"https://www.baidu.com/"]) {
        
        responsePolicy = WKNavigationResponsePolicyCancel;
    }
    decisionHandler(responsePolicy);
}
/**
 *  
 响应返回的的URL包含了https://www.baidu.com/，所以页面是不能被加载的，要是能加载就有下面的打印信息，注意和上面方法的区分对比！
 2016-08-11 13:53:38.392 RaectiveCocoaTest[17961:209778] 页面开始加载
 2016-08-11 13:53:38.675 RaectiveCocoaTest[17961:209778] https://www.baidu.com/
 2016-08-11 13:53:38.678 RaectiveCocoaTest[17961:209778] 内容正在加载当中
 2016-08-11 13:53:38.936 RaectiveCocoaTest[17961:209778] 页面加载完成
 */

// 创建方法，这个就不在多说了，重点放在下面几个
-(nullable WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures
{
    return nil;
}

// ios 9 之后才有的方法
-(void)webViewDidClose:(WKWebView *)webView
{
    
}

/**
下面这三个方法根据前面的字面意思就能区分记住！
 */
// runJavaScriptAlert
// 在JS端调用alert函数时，会触发此代理方法。
// JS端调用alert时所传的数据可以通过message,打印message信息读取出JS端给你的信息。
// 在原生得到结果后，需要回调给JS，通过completionHandler 回调给JS
// completionHandler 回调的参数和返回值都是空
-(void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler
{

    UIAlertController *alert = [UIAlertController alertControllerWithTitle:@"alert"message:@"JS调用alert"preferredStyle:UIAlertControllerStyleAlert];
    [alert addAction:[UIAlertAction actionWithTitle:@"确定" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
        
    }]];
    
    [self presentViewController:alert animated:YES completion:NULL];
    NSLog(@"%@", message);
    
}

// runJavaScriptTextInput
// 要求用户输入一段文本
// 在原生输入得到文本内容后，通过completionHandler回调给JS 大家注意这个回调的completionHandler参数是字符串
-(void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable))completionHandler
{

}

-(void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL))completionHandler
{
    
}