可以解决的问题:
1.
一:WKWebView的创建
/// 1.创建webview WKWebView *webView = [[WKWebView alloc] initWithFrame:self.view.bounds]; // 2.创建请求 NSMutableURLRequest *request =[NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://www.cnblogs.com/mddblog/"]]; // 3.加载网页 [webView loadRequest:request]; // 最后将webView添加到界面 [self.view addSubview:webView];
/// 其它三个加载函数 - (WKNavigation *)loadRequest:(NSURLRequest *)request; - (WKNavigation *)loadHTMLString:(NSString *)string baseURL:(nullable NSURL *)baseURL; - (WKNavigation *)loadData:(NSData *)data MIMEType:(NSString *)MIMEType characterEncodingName:(NSString *)characterEncodingName baseURL:(NSURL *)baseURL;
二:加载的状态回调(WKNavigationDelegate)【与UIWebView中的WebViewDelegate一样】(没有使用,但是用过UIWebView的)
作用:用来追踪页面的加载过程(页面开始加载、加载完成、加载失败)
// 页面开始加载时调用 - (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation; // 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; // 页面加载失败时调用 - (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(WKNavigation *)navigation;
页面跳转的代理方法:(还没用使用过,但见名识意)
// 接收到服务器跳转请求之后调用 - (void)webView:(WKWebView *)webView didReceiveServerRedirectForProvisionalNavigation:(WKNavigation *)navigation; // 在收到响应后,决定是否跳转 - (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler; // 在发送请求之前,决定是否跳转 - (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler;三:WKUIDelegate协议
这个协议主要用于WKWebVIew处理web界面的三种提示框(警示框、确认框、输入框)。代码如下:
//警告框 /** webView界面中有弹出警告框时调用 @param webView web视图调用委托方法 @param message 警告框提示内容 @param frame 主窗口 @param completionHandler 警告框消失调用 */ - (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler { completionHandler(); NSLog(@"警告框"); } //输入框 /** web界面中弹出输入框时调用 @param webView web视图调用委托方法 @param prompt 输入消息的显示 @param defaultText 初始化时显示的输入文本 @param frame 主窗口 @param completionHandler 输入结束后调用 */ -(void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable))completionHandler { NSLog(@"输入框"); completionHandler(@"http"); } //确认框 /** 显示一个JavaScript确认面板 @param webView web视图调用委托方法 @param message 显示的信息 @param frame 主窗口 @param completionHandler 确认后完成处理程序调用 */ -(void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL))completionHandler { NSLog(@"确认框"); completionHandler(YES); }*************调用block方法特别重要,否则,无法完成需要功能。会返回没有执行该方法的*****************
四:动态加载并运行JS代码
用于在客户端内部加入JS代码,并执行,示例如下:
// 图片缩放的js代码 NSString *js = @"var count = document.images.length;for (var i = 0; i < count; i++) {var image = document.images[i];image.style.width=320;};window.alert('找到' + count + '张图');"; // 根据JS字符串初始化WKUserScript对象 WKUserScript *script = [[WKUserScript alloc] initWithSource:js injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES]; // 根据生成的WKUserScript对象,初始化WKWebViewConfiguration WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init]; [config.userContentController addUserScript:script]; _webView = [[WKWebView alloc] initWithFrame:self.view.bounds configuration:config]; [_webView loadHTMLString:@"<head></head><imgea src='http://www.nsu.edu.cn/v/2014v3/img/background/3.jpg' />"baseURL:nil]; [self.view addSubview:_webView]; 五:webView执行JS代码
//javaScriptString是JS方法名,completionHandler是异步回调block [self.webView evaluateJavaScript:javaScriptString completionHandler:completionHandler];
再WKWebView里面注册供JS调用的方法,是通过WKUserContentController类下面的方法:
- (void)addScriptMessageHandler:(id <WKScriptMessageHandler>)scriptMessageHandler name:(NSString *)name;scriptMessageHandler是代理回调,JS调用name方法后,OC会调用scriptMessageHandler指定的对象。
JS在调用OC注册方法的时候要用下面的方式:
window.webkit.messageHandlers.<name>.postMessage(<messageBody>)注意,name(方法名)是放在中间的,messageBody只能是一个对象,如果要传多个值,需要封装成数组,或者字典。整个示例如下:
//OC注册供JS调用的方法 [[_webView configuration].userContentController addScriptMessageHandler:self name:@"closeMe"]; //OC在JS调用方法做的处理 - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message { NSLog(@"JS 调用了 %@ 方法,传回参数 %@",message.name,message.body); } //JS调用 window.webkit.messageHandlers.closeMe.postMessage(null);如果你在self的dealloc打个断点,会发现self没有释放!这显然是不行的!谷歌后看到一种解决方法,如下:
@interface WeakScriptMessageDelegate : NSObject<WKScriptMessageHandler> @property (nonatomic, weak) id<WKScriptMessageHandler> scriptDelegate; - (instancetype)initWithDelegate:(id<WKScriptMessageHandler>)scriptDelegate; @end @implementation WeakScriptMessageDelegate - (instancetype)initWithDelegate:(id<WKScriptMessageHandler>)scriptDelegate { self = [super init]; if (self) { _scriptDelegate = scriptDelegate; } return self; } - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message { [self.scriptDelegate userContentController:userContentController didReceiveScriptMessage:message]; } @end思路是另外创建一个代理对象,然后通过代理对象回调指定的self,
WKUserContentController *userContentController = [[WKUserContentController alloc] init]; [userContentController addScriptMessageHandler:[[WeakScriptMessageDelegate alloc] initWithDelegate:self] name:@"closeMe"];运行代码,self释放了,WeakScriptMessageDelegate却没有释放啊啊啊! 还需在self的dealloc里面 添加这样一句代码:
[[_webView configuration].userContentController removeScriptMessageHandlerForName:@"closeMe"]; 注:WKWebView只是ios8后才能用