WKWebView 的使用简介

WKWebView相对于UIWebView强大了很多，内存的消耗相对少了，所提供的接口也丰富了。

现在谈一谈WKWebView的基本使用

1. navigationDelegate

- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation { // 类似UIWebView的 -webViewDidStartLoad:
    NSLog(@"didStartProvisionalNavigation");
    [UIApplication sharedApplication].networkActivityIndicatorVisible = YES;
}

- (void)webView:(WKWebView *)webView didCommitNavigation:(WKNavigation *)navigation {
    NSLog(@"didCommitNavigation");
}

- (void)webView:(WKWebView *)webView didFinishNavigation:(WKNavigation *)navigation { // 类似 UIWebView 的 －webViewDidFinishLoad:
    NSLog(@"didFinishNavigation");
    [self resetControl];
    if (webView.title.length > 0) {
        self.title = webView.title;
    }

}
- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation withError:(NSError *)error {
    // 类似 UIWebView 的- webView:didFailLoadWithError:

    NSLog(@"didFailProvisionalNavigation");
    
}
- (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler {
    
    decisionHandler(WKNavigationResponsePolicyAllow);
}

- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    // 类似 UIWebView 的 -webView: shouldStartLoadWithRequest: navigationType:

    NSLog(@"4.%@",navigationAction.request);

    
    NSString *url = [navigationAction.request.URL.absoluteString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

    
    
    decisionHandler(WKNavigationActionPolicyAllow);

}
- (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition, NSURLCredential *))completionHandler {
    
}

2 UIDelegate

- (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures {
    // 接口的作用是打开新窗口委托
    [self createNewWebViewWithURL:webView.URL.absoluteString config:configuration];
    
    return currentSubView.webView;
}

- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)())completionHandler
{    // js 里面的alert实现，如果不实现，网页的alert函数无效
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:message
                                                                             message:nil
                                                                      preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:@"确定"
                                                        style:UIAlertActionStyleCancel
                                                      handler:^(UIAlertAction *action) {
                                                          completionHandler();
                                                      }]];
    
    [self presentViewController:alertController animated:YES completion:^{}];
    
}

- (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL))completionHandler {
    //  js 里面的alert实现，如果不实现，网页的alert函数无效  , 

    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:message
                                                                             message:nil
                                                                      preferredStyle:UIAlertControllerStyleAlert];
    [alertController addAction:[UIAlertAction actionWithTitle:@"确定"
                                                        style:UIAlertActionStyleDefault
                                                      handler:^(UIAlertAction *action) {
                                                          completionHandler(YES);
                                                      }]];
    [alertController addAction:[UIAlertAction actionWithTitle:@"取消"
                                                        style:UIAlertActionStyleCancel
                                                      handler:^(UIAlertAction *action){
                                                          completionHandler(NO);
                                                      }]];
    
    [self presentViewController:alertController animated:YES completion:^{}];
    
}

- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString *))completionHandler {
    
    completionHandler(@"Client Not handler");
    
}

3. WKWebView 执行脚本方法

- (void)evaluateJavaScript:(NSString *)javaScriptString completionHandler:(void (^)(id, NSError *))completionHandler;

completionHandler 拥有两个参数，一个是返回错误，一个可以返回执行脚本后的返回值

4. WKWebView 的Cookie问题

UIWebView 中会自动保存Cookie，如果登录了一次，下次再次进入的时候，会记住登录状态

而在WKWebView中，并不会这样，WKWebView在初始化的时候有一个方法

- (instancetype)initWithFrame:(CGRect)frame configuration:(WKWebViewConfiguration *)configuration

通过这个方法，设置 configuration 让WKWebView知道登录状态，configuration 可以通过已有的Cookie进行设置，也可以通过保存上一次的configuration进行设置

参考 stackoverflow上回答：http://stackoverflow.com/questions/26573137/can-i-set-the-cookies-to-be-used-by-a-wkwebview/26577303#26577303

WKWebView * webView = /*set up your webView*/
NSMutableURLRequest * request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://example.com/index.html"]];
[request addValue:@"TeskCookieKey1=TeskCookieValue1;TeskCookieKey2=TeskCookieValue2;" forHTTPHeaderField:@"Cookie"];
// use stringWithFormat: in the above line to inject your values programmatically
[webView loadRequest:request];

WKUserContentController* userContentController = WKUserContentController.new;
WKUserScript * cookieScript = [[WKUserScript alloc] 
    initWithSource: @"document.cookie = 'TeskCookieKey1=TeskCookieValue1';document.cookie = 'TeskCookieKey2=TeskCookieValue2';"
    injectionTime:WKUserScriptInjectionTimeAtDocumentStart forMainFrameOnly:NO];
// again, use stringWithFormat: in the above line to inject your values programmatically
[userContentController addUserScript:cookieScript];
WKWebViewConfiguration* webViewConfig = WKWebViewConfiguration.new;
webViewConfig.userContentController = userContentController;
WKWebView * webView = [[WKWebView alloc] initWithFrame:CGRectMake(/*set your values*/) configuration:webViewConfig];