ios wkweb设置图片_iOS WKWebView的使用

WKWebView的使用

前言

最近项目中的UIWebView被替换为了WKWebView，因此来总结一下。

示例Demo：WKWebView的使用

本文将从以下几方面介绍WKWebView：

1、WKWebView涉及的一些类

2、WKWebView涉及的代理方法

3、网页内容加载进度条和title的实现

4、JS和OC的交互

5、本地HTML文件的实现

6、WKWebView+UITableView混排

7、WKWebView离线缓存功能

一、WKWebView涉及的一些类

WKWebView：网页的渲染与展示

注意： #import

//初始化

_webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT) configuration:config];

// UI代理

_webView.UIDelegate = self;

// 导航代理

_webView.navigationDelegate = self;

// 是否允许手势左滑返回上一级, 类似导航控制的左滑返回

_webView.allowsBackForwardNavigationGestures = YES;

//可返回的页面列表, 存储已打开过的网页

WKBackForwardList * backForwardList = [_webView backForwardList];

// NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://www.chinadaily.com.cn"]];

// [request addValue:[self readCurrentCookieWithDomain:@"http://www.chinadaily.com.cn"] forHTTPHeaderField:@"Cookie"];

// [_webView loadRequest:request];

//页面后退

[_webView goBack];

//页面前进

[_webView goForward];

//刷新当前页面

[_webView reload];

NSString *path = [[NSBundle mainBundle] pathForResource:@"JStoOC.html" ofType:nil];

NSString *htmlString = [[NSString alloc]initWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];

//加载本地html文件

[_webView loadHTMLString:htmlString baseURL:[NSURL fileURLWithPath:[[NSBundle mainBundle] bundlePath]]];

WKWebViewConfiguration：为添加WKWebView配置信息

//创建网页配置对象

WKWebViewConfiguration *config = [[WKWebViewConfiguration alloc] init];

// 创建设置对象

WKPreferences *preference = [[WKPreferences alloc]init];

//最小字体大小当将javaScriptEnabled属性设置为NO时，可以看到明显的效果

preference.minimumFontSize = 0;

//设置是否支持javaScript 默认是支持的

preference.javaScriptEnabled = YES;

// 在iOS上默认为NO，表示是否允许不经过用户交互由javaScript自动打开窗口

preference.javaScriptCanOpenWindowsAutomatically = YES;

config.preferences = preference;

// 是使用h5的视频播放器在线播放, 还是使用原生播放器全屏播放

config.allowsInlineMediaPlayback = YES;

//设置视频是否需要用户手动播放设置为NO则会允许自动播放

config.requiresUserActionForMediaPlayback = YES;

//设置是否允许画中画技术在特定设备上有效

config.allowsPictureInPictureMediaPlayback = YES;

//设置请求的User-Agent信息中应用程序名称 iOS9后可用

config.applicationNameForUserAgent = @"ChinaDailyForiPad";

//自定义的WKScriptMessageHandler 是为了解决内存不释放的问题

WeakWebViewScriptMessageDelegate *weakScriptMessageDelegate = [[WeakWebViewScriptMessageDelegate alloc] initWithDelegate:self];

//这个类主要用来做native与JavaScript的交互管理

WKUserContentController * wkUController = [[WKUserContentController alloc] init];

//注册一个name为jsToOcNoPrams的js方法

[wkUController addScriptMessageHandler:weakScriptMessageDelegate name:@"jsToOcNoPrams"];

[wkUController addScriptMessageHandler:weakScriptMessageDelegate name:@"jsToOcWithPrams"];

config.userContentController = wkUController;

WKUserScript：用于进行JavaScript注入

//以下代码适配文本大小，由UIWebView换为WKWebView后，会发现字体小了很多，这应该是WKWebView与html的兼容问题，解决办法是修改原网页，要么我们手动注入JS

NSString *jSString = @"var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width'); document.getElementsByTagName('head')[0].appendChild(meta);";

//用于进行JavaScript注入

WKUserScript *wkUScript = [[WKUserScript alloc] initWithSource:jSString injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];

[config.userContentController addUserScript:wkUScript];

WKUserContentController：这个类主要用来做native与JavaScript的交互管理

//这个类主要用来做native与JavaScript的交互管理

WKUserContentController * wkUController = [[WKUserContentController alloc] init];

//注册一个name为jsToOcNoPrams的js方法，设置处理接收JS方法的代理

[wkUController addScriptMessageHandler:self name:@"jsToOcNoPrams"];

[wkUController addScriptMessageHandler:self name:@"jsToOcWithPrams"];

config.userContentController = wkUController;

//用完记得移除

//移除注册的js方法

[[_webView configuration].userContentController removeScriptMessageHandlerForName:@"jsToOcNoPrams"];

[[_webView configuration].userContentController removeScriptMessageHandlerForName:@"jsToOcWithPrams"];

WKScriptMessageHandler：这个协议类专门用来处理监听JavaScript方法从而调用原生OC方法，和WKUserContentController搭配使用。

注意：遵守WKScriptMessageHandler协议，代理是由WKUserContentControl设置

//通过接收JS传出消息的name进行捕捉的回调方法

- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{

NSLog(@"name:%@\\\\n body:%@\\\\n frameInfo:%@\\\\n",message.name,message.body,message.frameInfo);

//用message.body获得JS传出的参数体

NSDictionary * parameter = message.body;

//JS调用OC

if([message.name isEqualToString:@"jsToOcNoPrams"]){

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"js调用到了oc" message:@"不带参数" 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调用到了oc" message:parameter[@"params"] preferredStyle:UIAlertControllerStyleAlert];

[alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

}])];

[self presentViewController:alertController animated:YES completion:nil];

}

二、WKWebView涉及的代理方法

WKNavigationDelegate ：主要处理一些跳转、加载处理操作

// 页面开始加载时调用

- (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation {

}

// 页面加载失败时调用

- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error {

[self.progressView setProgress:0.0f animated:NO];

}

// 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 {

[self getCookie];

}

//提交发生错误时调用

- (void)webView:(WKWebView *)webView didFailNavigation:(WKNavigation *)navigation withError:(NSError *)error {

[self.progressView setProgress:0.0f animated:NO];

}

// 接收到服务器跳转请求即服务重定向时之后调用

- (void)webView:(WKWebView *)webView didReceiveServerRedirectForProvisionalNavigation:(WKNavigation *)navigation {

}

// 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 {

NSString * urlStr = navigationAction.request.URL.absoluteString;

NSLog(@"发送跳转请求：%@",urlStr);

//自己定义的协议头

NSString *htmlHeadString = @"github://";

if([urlStr hasPrefix:htmlHeadString]){

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"通过截取URL调用OC" message:@"你想前往我的Github主页?" preferredStyle:UIAlertControllerStyleAlert];

[alertController addAction:([UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {

}])];

[alertController addAction:([UIAlertAction actionWithTitle:@"打开" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

NSURL * url = [NSURL URLWithString:[urlStr stringByReplacingOccurrencesOfString:@"github://callName_?" withString:@""]];

[[UIApplication sharedApplication] openURL:url];

}])];

[self presentViewController:alertController animated:YES completion:nil];

decisionHandler(WKNavigationActionPolicyCancel);

}else{

decisionHandler(WKNavigationActionPolicyAllow);

}

// 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{

NSString * urlStr = navigationResponse.response.URL.absoluteString;

NSLog(@"当前跳转地址：%@",urlStr);

//允许跳转

decisionHandler(WKNavigationResponsePolicyAllow);

//不允许跳转

//decisionHandler(WKNavigationResponsePolicyCancel);

}

//需要响应身份验证时调用同样在block中需要传入用户身份凭证

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

//用户身份信息

NSURLCredential * newCred = [[NSURLCredential alloc] initWithUser:@"user123" password:@"123" persistence:NSURLCredentialPersistenceNone];

//为 challenge 的发送方提供 credential

[challenge.sender useCredential:newCred forAuthenticationChallenge:challenge];

completionHandler(NSURLSessionAuthChallengeUseCredential,newCred);

}

//进程被终止时调用

- (void)webViewWebContentProcessDidTerminate:(WKWebView *)webView{

}

WKUIDelegate ：主要处理JS脚本，确认框，警告框等

/**

* web界面中有弹出警告框时调用

* @param webView 实现该代理的webview

* @param message 警告框中的内容

* @param completionHandler 警告框消失调用

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

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"HTML的弹出框" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];

[alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

completionHandler();

}])];

[self presentViewController:alertController animated:YES completion:nil];

}

// 确认框

//JavaScript调用confirm方法后回调的方法 confirm是js中的确定框，需要在block中把用户选择的情况传递进去

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

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"" message:message?:@"" preferredStyle:UIAlertControllerStyleAlert];

[alertController addAction:([UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:^(UIAlertAction * _Nonnull action) {

completionHandler(NO);

}])];

[alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

completionHandler(YES);

}])];

[self presentViewController:alertController animated:YES completion:nil];

}

// 输入框

//JavaScript调用prompt方法后回调的方法 prompt是js中的输入框需要在block中把用户输入的信息传入

- (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * _Nullable))completionHandler{

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:prompt message:@"" preferredStyle:UIAlertControllerStyleAlert];

[alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {

textField.text = defaultText;

}];

[alertController addAction:([UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {

completionHandler(alertController.textFields[0].text?:@"");

}])];

[self presentViewController:alertController animated:YES completion:nil];

}

// 页面是弹出窗口 _blank 处理

- (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures {

if (!navigationAction.targetFrame.isMainFrame) {

[webView loadRequest:navigationAction.request];

}

return nil;

}

三、网页内容加载进度条和title的实现

//添加监测网页加载进度的观察者

[self.webView addObserver:self

forKeyPath:@"estimatedProgress"

options:0

context:nil];

//添加监测网页标题title的观察者

[self.webView addObserver:self

forKeyPath:@"title"

options:NSKeyValueObservingOptionNew

context:nil];

//kvo 监听进度必须实现此方法

-(void)observeValueForKeyPath:(NSString *)keyPath

ofObject:(id)object

change:(NSDictionary *)change

context:(void *)context{

if ([keyPath isEqualToString:NSStringFromSelector(@selector(estimatedProgress))]

&& object == _webView) {

NSLog(@"网页加载进度 = %f",_webView.estimatedProgress);

self.progressView.progress = _webView.estimatedProgress;

if (_webView.estimatedProgress >= 1.0f) {

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{

self.progressView.progress = 0;

});

}

}else if([keyPath isEqualToString:@"title"]

&& object == _webView){

self.navigationItem.title = _webView.title;

}else{

[super observeValueForKeyPath:keyPath

ofObject:object

change:change

context:context];

}

//移除观察者

[_webView removeObserver:self

forKeyPath:NSStringFromSelector(@selector(estimatedProgress))];

[_webView removeObserver:self

forKeyPath:NSStringFromSelector(@selector(title))];

四、JS和OC的交互

JS调用OC

这个实现主要是依靠WKScriptMessageHandler协议类和WKUserContentController两个类：WKUserContentController对象负责注册JS方法，设置处理接收JS方法的代理，代理遵守WKScriptMessageHandler，实现捕捉到JS消息的回调方法，详情可以看第一步中对这两个类的介绍。

//这个类主要用来做native与JavaScript的交互管理

WKUserContentController * wkUController = [[WKUserContentController alloc] init];

//注册一个name为jsToOcNoPrams的js方法，设置处理接收JS方法的代理

[wkUController addScriptMessageHandler:self name:@"jsToOcNoPrams"];

[wkUController addScriptMessageHandler:self name:@"jsToOcWithPrams"];

config.userContentController = wkUController;

注意：遵守WKScriptMessageHandler协议，代理是由WKUserContentControl设置

//通过接收JS传出消息的name进行捕捉的回调方法 js调OC

- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message{

NSLog(@"name:%@\\\\n body:%@\\\\n frameInfo:%@\\\\n",message.name,message.body,message.frameInfo);

}

OC调用JS