iOS网络3—UIWebView与WKWebView使用详解
一、整体介绍
UIWebView
自iOS2就有,WKWebView
从iOS8才有,毫无疑问WKWebView
将逐步取代笨重的UIWebView
。通过简单的测试即可发现UIWebView
占用过多内存,且内存峰值更是夸张。WKWebView
网页加载速度也有提升,但是并不像内存那样提升那么多。下面列举一些其它的优势:
- 更多的支持HTML5的特性
- 官方宣称的高达60fps的滚动刷新率以及内置手势
- Safari相同的JavaScript引擎
- 将UIWebViewDelegate与UIWebView拆分成了14类与3个协议(官方文档说明)
- 另外用的比较多的,增加加载进度属性:
estimatedProgress
二、UIWebView使用说明
1 举例:简单的使用
UIWebView
使用非常简单,可以分为三步,也是最简单的用法,显示网页
- (void)simpleExampleTest { // 1.创建webview,并设置大小,"20"为状态栏高度 UIWebView *webView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 20, self.view.frame.size.width, self.view.frame.size.height - 20)]; // 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]; }
2 一些实用函数
- 加载函数。
- (void)loadRequest:(NSURLRequest *)request; - (void)loadHTMLString:(NSString *)string baseURL:(nullable NSURL *)baseURL; - (void)loadData:(NSData *)data MIMEType:(NSString *)MIMEType textEncodingName:(NSString *)textEncodingName baseURL:(NSURL *)baseURL;
UIWebView
不仅可以加载HTML页面,还支持pdf、word、txt、各种图片等等的显示。下面以加载mac桌面上的png图片:/Users/coohua/Desktop/bigIcon.png
为例
// 1.获取url NSURL *url = [NSURL fileURLWithPath:@"/Users/coohua/Desktop/bigIcon.png"]; // 2.创建请求 NSURLRequest *request=[NSURLRequest requestWithURL:url]; // 3.加载请求 [self.webView loadRequest:request];
- 网页导航刷新有关函数
// 刷新 - (void)reload; // 停止加载 - (void)stopLoading; // 后退函数 - (void)goBack; // 前进函数 - (void)goForward; // 是否可以后退 @property (nonatomic, readonly, getter=canGoBack) BOOL canGoBack; // 是否可以向前 @property (nonatomic, readonly, getter=canGoForward) BOOL canGoForward; // 是否正在加载 @property (nonatomic, readonly, getter=isLoading) BOOL loading;
3 代理协议使用:UIWebViewDelegate
一共有四个方法
/// 是否允许加载网页,也可获取js要打开的url,通过截取此url可与js交互 - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType { NSString *urlString = [[request URL] absoluteString]; urlString = [urlString stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding]; NSArray *urlComps = [urlString componentsSeparatedByString:@"://"]; NSLog(@"urlString=%@---urlComps=%@",urlString,urlComps); return YES; } /// 开始加载网页 - (void)webViewDidStartLoad:(UIWebView *)webView { NSURLRequest *request = webView.request; NSLog(@"webViewDidStartLoad-url=%@--%@",[request URL],[request HTTPBody]); } /// 网页加载完成 - (void)webViewDidFinishLoad:(UIWebView *)webView { NSURLRequest *request = webView.request; NSURL *url = [request URL]; if ([url.path isEqualToString:@"/normal.html"]) { NSLog(@"isEqualToString"); } NSLog(@"webViewDidFinishLoad-url=%@--%@",[request URL],[request HTTPBody]); NSLog(@"%@",[self.webView stringByEvaluatingJavaScriptFromString:@"document.title"]); } /// 网页加载错误 - (void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error { NSURLRequest *request = webView.request; NSLog(@"didFailLoadWithError-url=%@--%@",[request URL],[request HTTPBody]); }
4 与js交互
主要有两方面:js执行OC代码、oc调取写好的js代码
- js执行OC代码:js是不能执行oc代码的,但是可以变相的执行,js可以将要执行的操作封装到网络请求里面,然后oc拦截这个请求,获取url里面的字符串解析即可,这里用到代理协议的
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
函数。 - oc调取写好的js代码:这里用到UIwebview的一个方法。示例代码一个是网页定位,一个是获取网页title:
// 实现自动定位js代码, htmlLocationID为定位的位置(由js开发人员给出),实现自动定位代码,应该在网页加载完成之后再调用 NSString *javascriptStr = [NSString stringWithFormat:@"window.location.href = '#%@'",htmlLocationID]; // webview执行代码 [self.webView stringByEvaluatingJavaScriptFromString:javascriptStr]; // 获取网页的title NSString *title = [self.webView stringByEvaluatingJavaScriptFromString:@"document.title"];
- 与js交互的实例
很多时候,我们要对网页做一些编辑,比如加载一个网页后,个别原因,我们不想显示新闻的来源,如下图的新闻来源“新华网”,网页的链接如下:http://op.inews.qq.com/mcms/h5/default/detail?id=NEW2016103101306200&refer=100000050
(可能已经失效)
那我们就可以使用js代码将这个标签去掉,且只留下时间。js代码的编写,根据火狐浏览器查看它的标签名称,然后做处理,如上图,具体代码如下:
- (void)deleteNewsSource { // 1.去掉页面标题 NSMutableString *str = [NSMutableString string]; // 去掉导航页,如果想把“腾讯新闻”导航栏一并去掉,就打开注释 // [str appendString:@"document.getElementsByClassName('g-header')[0].style.display = 'none';"]; // 来源 [str appendString:@"if(document.getElementsByClassName('g-wrapper-author')[0].innerHTML.indexOf(' ') == -1){document.getElementsByClassName('g-wrapper-author')[0].innerHTML = document.getElementsByClassName('g-wrapper-author')[0].innerHTML}else{document.getElementsByClassName('g-wrapper-author')[0].innerHTML = document.getElementsByClassName('g-wrapper-author')[0].innerHTML.split(' ')[1];}"]; // 执行js代码 [_webView stringByEvaluatingJavaScriptFromString:str]; }
代码执行的时机,一般情况下是等待网页加载完成- (void)webViewDidFinishLoad:(UIWebView *)webView
里面执行,比较合理,但是有延迟,我们会发现刚开始有来源,然后突然又没有了,即js代码执行有延迟。
这样的话,我们可以在- (void)webViewDidStartLoad:(UIWebView *)webView
网页开始加载里面开启一个定时器,比如定时0.2秒(根据需要自己设定),在定时器里面不停的调用- (void)deleteNewsSource
方法即可解决。然后在- (void)webViewDidFinishLoad:(UIWebView *)webView
里面关掉定时器。另外定时器容易引起循环引用,一定要注意释放。比如可以在viewDidDisappear方法里释放定时器。。。
- (void)webViewDidStartLoad:(UIWebView *)webView { // 1.去掉页面来源标签,时间根据需要自己设置,定时器在这里开启具有一定危险性 NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:0.2 target:self selector:@selector(deleteNewsSource) userInfo:nil repeats:YES]; [[NSRunLoop mainRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode]; self.timer = timer; }
三、WKWebView使用说明
1 简单使用
与UIWebview一样,仅需三步:
- (void)simpleExampleTest { // 1.创建webview,并设置大小,"20"为状态栏高度 WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 20, self.view.frame.size.width, self.view.frame.size.height - 20)]; // 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]; }
2 一些实用函数
- 加载网页函数
相比UIWebview,WKWebView也支持各种文件格式,并新增了loadFileURL
函数,顾名思义加载本地文件,不要用loadRequest来加载本地HTML,另外,加载网页显示属于UI,所以应在主线程里面执行加载网页函数,不过即使在其它线程执行了加载网页函数,也没关系,苹果已做了处理,保证UI在主线程更新。
/// 模拟器调试加载mac本地文件 - (void)loadLocalFile { // 1.创建webview,并设置大小,"20"为状态栏高度 WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 20, self.view.frame.size.width, self.view.frame.size.height - 20)]; // 2.创建url userName:电脑用户名 NSURL *url = [NSURL fileURLWithPath:@"/Users/userName/Desktop/bigIcon.png"]; // 3.加载文件 [webView loadFileURL:url allowingReadAccessToURL:url]; // 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;
- 网页导航刷新相关函数
和UIWebview几乎一样,不同的是有返回值,WKNavigation(已更新),另外增加了函数reloadFromOrigin
和goToBackForwardListItem
。
- reloadFromOrigin会比较网络数据是否有变化,没有变化则使用缓存,否则从新请求。
- goToBackForwardListItem:比向前向后更强大,可以跳转到某个指定历史页面
@property (nonatomic, readonly) BOOL canGoBack; @property (nonatomic, readonly) BOOL canGoForward; - (WKNavigation *)goBack; - (WKNavigation *)goForward; - (WKNavigation *)reload; - (WKNavigation *)reloadFromOrigin; // 增加的函数 - (WKNavigation *)goToBackForwardListItem:(WKBackForwardListItem *)item; // 增加的函数 - (void)stopLoading;
- 一些常用属性
- allowsBackForwardNavigationGestures:BOOL类型,是否允许左右划手势导航,默认不允许
- estimatedProgress:加载进度,取值范围0~1
- title:页面title
- .scrollView.scrollEnabled:是否允许上下滚动,默认允许
- backForwardList:WKBackForwardList类型,访问历史列表,可以通过前进后退按钮访问,或者通过goToBackForwardListItem函数跳到指定页面
-
执行js代码
/// jsStr为要执行的js代码,字符串形式 [webView evaluateJavaScript:jsStr completionHandler:^(id item, NSError * _Nullable error) { // 执行结果回调 }];
3 代理协议使用
一共有三个代理协议:
- WKNavigationDelegate:最常用,和UIWebViewDelegate功能类似,追踪加载过程,有是否允许加载、开始加载、加载完成、加载失败。下面会对函数做简单的说明,并用数字标出调用的先后次序:1-2-3-4-5
三个是否允许加载函数:
/// 接收到服务器跳转请求之后调用 (服务器端redirect),不一定调用 - (void)webView:(WKWebView *)webView didReceiveServerRedirectForProvisionalNavigation:(WKNavigation *)navigation; /// 3 在收到服务器的响应头,根据response相关信息,决定是否跳转。decisionHandler必须调用,来决定是否跳转,参数WKNavigationActionPolicyCancel取消跳转,WKNavigationActionPolicyAllow允许跳转 - (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler; /// 1 在发送请求之前,决定是否跳转 - (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler;
追踪加载过程函数:
/// 2 页面开始加载 - (void)webView:(WKWebView *)webView didStartProvisionalNavigation:(WKNavigation *)navigation; /// 4 开始获取到网页内容时返回 - (void)webView:(WKWebView *)webView didCommitNavigation:(WKNavigation *)navigation; /// 5 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;
- WKScriptMessageHandler:必须实现的函数,是APP与js交互,提供从网页中收消息的回调方法,即js可以调用app的方法
当然需要对webview做一些特殊处理,创建的时候调用initWithFrame:configuration:
做一些配置,configuration
为WKWebViewConfiguration
类型,具体不再详述,代理方法如下:
/// message: 收到的脚本信息. - (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message;
当然,app也可以执行js代码,如下:
/// jsStr为要执行的js代码,字符串形式 [webView evaluateJavaScript:jsStr completionHandler:^(id item, NSError * _Nullable error) { // 执行结果回调 }];
- WKUIDelegate:UI界面相关,原生控件支持,三种提示框:输入、确认、警告。首先将web提示框拦截然后再做处理。
/// 创建一个新的WebView - (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures; /// 输入框 - (void)webView:(WKWebView *)webView runJavaScriptTextInputPanelWithPrompt:(NSString *)prompt defaultText:(nullable NSString *)defaultText initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(NSString * __nullable result))completionHandler; /// 确认框 - (void)webView:(WKWebView *)webView runJavaScriptConfirmPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(BOOL result))completionHandler; /// 警告框 - (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(WKFrameInfo *)frame completionHandler:(void (^)(void))completionHandler;
四、示例代码
- 代码可以实现一般网络显示,加载本地文件(pdf、word、txt、图片等等)
- 搜索框搜索界面,搜索框输入
file://
则加载本地文件,http://
则加载网络内容,如果两者都不是则搜索输入的关键字。 - 下部网络导航,后退、前进、刷新、用Safari打开链接四个按钮
/// 控件高度 #define kSearchBarH 44 #define kBottomViewH 44 /// 屏幕大小尺寸 #define kScreenWidth [UIScreen mainScreen].bounds.size.width #define kScreenHeight [UIScreen mainScreen].bounds.size.height #import "ViewController.h" #import <WebKit/WebKit.h> @interface ViewController () <UISearchBarDelegate, WKNavigationDelegate> @property (nonatomic, strong) UISearchBar *searchBar; /// 网页控制导航栏 @property (weak, nonatomic) UIView *bottomView; @property (nonatomic, strong) WKWebView *wkWebView; @property (weak, nonatomic) UIButton *backBtn; @property (weak, nonatomic) UIButton *forwardBtn; @property (weak, nonatomic) UIButton *reloadBtn; @property (weak, nonatomic) UIButton *browserBtn; @property (weak, nonatomic) NSString *baseURLString; @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // [self simpleExampleTest]; [self addSubViews]; [self refreshBottomButtonState]; [self.wkWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.cnblogs.com/mddblog/"]]]; } - (void)simpleExampleTest { // 1.创建webview,并设置大小,"20"为状态栏高度 WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 20, self.view.frame.size.width, self.view.frame.size.height - 20)]; // 2.创建请求 NSMutableURLRequest *request =[NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"http://www.cnblogs.com/mddblog/"]]; // // 3.加载网页 [webView loadRequest:request]; // [webView loadFileURL:[NSURL fileURLWithPath:@"/Users/userName/Desktop/bigIcon.png"] allowingReadAccessToURL:[NSURL fileURLWithPath:@"/Users/userName/Desktop/bigIcon.png"]]; // 最后将webView添加到界面 [self.view addSubview:webView]; } /// 模拟器加载mac本地文件 - (void)loadLocalFile { // 1.创建webview,并设置大小,"20"为状态栏高度 WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 20, self.view.frame.size.width, self.view.frame.size.height - 20)]; // 2.创建url userName:电脑用户名 NSURL *url = [NSURL fileURLWithPath:@"/Users/userName/Desktop/bigIcon.png"]; // 3.加载文件 [webView loadFileURL:url allowingReadAccessToURL:url]; // 最后将webView添加到界面 [self.view addSubview:webView]; } - (void)addSubViews { [self addBottomViewButtons]; [self.view addSubview:self.searchBar]; [self.view addSubview:self.wkWebView]; } - (void)addBottomViewButtons { // 记录按钮个数 int count = 0; // 添加按钮 UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom]; [button setTitle:@"后退" forState:UIControlStateNormal]; [button setTitleColor:[UIColor colorWithRed:249 / 255.0 green:102 / 255.0 blue:129 / 255.0 alpha:1.0] forState:UIControlStateNormal]; [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateHighlighted]; [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateDisabled]; [button.titleLabel setFont:[UIFont systemFontOfSize:15]]; button.tag = ++count; // 标记按钮 [button addTarget:self action:@selector(onBottomButtonsClicled:) forControlEvents:UIControlEventTouchUpInside]; [self.bottomView addSubview:button]; self.backBtn = button; button = [UIButton buttonWithType:UIButtonTypeCustom]; [button setTitle:@"前进" forState:UIControlStateNormal]; [button setTitleColor:[UIColor colorWithRed:249 / 255.0 green:102 / 255.0 blue:129 / 255.0 alpha:1.0] forState:UIControlStateNormal]; [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateHighlighted]; [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateDisabled]; [button.titleLabel setFont:[UIFont systemFontOfSize:15]]; button.tag = ++count; [button addTarget:self action:@selector(onBottomButtonsClicled:) forControlEvents:UIControlEventTouchUpInside]; [self.bottomView addSubview:button]; self.forwardBtn = button; button = [UIButton buttonWithType:UIButtonTypeCustom]; [button setTitle:@"重新加载" forState:UIControlStateNormal]; [button setTitleColor:[UIColor colorWithRed:249 / 255.0 green:102 / 255.0 blue:129 / 255.0 alpha:1.0] forState:UIControlStateNormal]; [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateHighlighted]; [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateDisabled]; [button.titleLabel setFont:[UIFont systemFontOfSize:15]]; button.tag = ++count; [button addTarget:self action:@selector(onBottomButtonsClicled:) forControlEvents:UIControlEventTouchUpInside]; [self.bottomView addSubview:button]; self.reloadBtn = button; button = [UIButton buttonWithType:UIButtonTypeCustom]; [button setTitle:@"Safari" forState:UIControlStateNormal]; [button setTitleColor:[UIColor colorWithRed:249 / 255.0 green:102 / 255.0 blue:129 / 255.0 alpha:1.0] forState:UIControlStateNormal]; [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateHighlighted]; [button setTitleColor:[UIColor lightGrayColor] forState:UIControlStateDisabled]; [button.titleLabel setFont:[UIFont systemFontOfSize:15]]; button.tag = ++count; [button addTarget:self action:@selector(onBottomButtonsClicled:) forControlEvents:UIControlEventTouchUpInside]; [self.bottomView addSubview:button]; self.browserBtn = button; // 统一设置frame [self setupBottomViewLayout]; } - (void)setupBottomViewLayout { int count = 4; CGFloat btnW = 80; CGFloat btnH = 30; CGFloat btnY = (self.bottomView.bounds.size.height - btnH) / 2; // 按钮间间隙 CGFloat margin = (self.bottomView.bounds.size.width - btnW * count) / count; CGFloat btnX = margin * 0.5; self.backBtn.frame = CGRectMake(btnX, btnY, btnW, btnH); btnX = self.backBtn.frame.origin.x + btnW + margin; self.forwardBtn.frame = CGRectMake(btnX, btnY, btnW, btnH); btnX = self.forwardBtn.frame.origin.x + btnW + margin; self.reloadBtn.frame = CGRectMake(btnX, btnY, btnW, btnH); btnX = self.reloadBtn.frame.origin.x + btnW + margin; self.browserBtn.frame = CGRectMake(btnX, btnY, btnW, btnH); } /// 刷新按钮是否允许点击 - (void)refreshBottomButtonState { if ([self.wkWebView canGoBack]) { self.backBtn.enabled = YES; } else { self.backBtn.enabled = NO; } if ([self.wkWebView canGoForward]) { self.forwardBtn.enabled = YES; } else { self.forwardBtn.enabled = NO; } } /// 按钮点击事件 - (void)onBottomButtonsClicled:(UIButton *)sender { switch (sender.tag) { case 1: { [self.wkWebView goBack]; [self refreshBottomButtonState]; } break; case 2: { [self.wkWebView goForward]; [self refreshBottomButtonState]; } break; case 3: [self.wkWebView reload]; break; case 4: [[UIApplication sharedApplication] openURL:self.wkWebView.URL]; break; default: break; } } #pragma mark - WKWebView WKNavigationDelegate 相关 /// 是否允许加载网页 在发送请求之前,决定是否跳转 - (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler { NSString *urlString = [[navigationAction.request URL] absoluteString]; urlString = [urlString stringByRemovingPercentEncoding]; // NSLog(@"urlString=%@",urlString); // 用://截取字符串 NSArray *urlComps = [urlString componentsSeparatedByString:@"://"]; if ([urlComps count]) { // 获取协议头 NSString *protocolHead = [urlComps objectAtIndex:0]; NSLog(@"protocolHead=%@",protocolHead); } decisionHandler(WKNavigationActionPolicyAllow); } #pragma mark - searchBar代理方法 /// 点击搜索按钮 - (void)searchBarSearchButtonClicked:(UISearchBar *)searchBar { // 创建url NSURL *url = nil; NSString *urlStr = searchBar.text; // 如果file://则为打开bundle本地文件,http则为网站,否则只是一般搜索关键字 if([urlStr hasPrefix:@"file://"]){ NSRange range = [urlStr rangeOfString:@"file://"]; NSString *fileName = [urlStr substringFromIndex:range.length]; url = [[NSBundle mainBundle] URLForResource:fileName withExtension:nil]; // 如果是模拟器加载电脑上的文件,则用下面的代码 // url = [NSURL fileURLWithPath:fileName]; }else if(urlStr.length>0){ if ([urlStr hasPrefix:@"http://"]) { url=[NSURL URLWithString:urlStr]; } else { urlStr=[NSString stringWithFormat:@"http://www.baidu.com/s?wd=%@",urlStr]; } urlStr = [urlStr stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLQueryAllowedCharacterSet]]; url=[NSURL URLWithString:urlStr]; } NSURLRequest *request=[NSURLRequest requestWithURL:url]; // 加载请求页面 [self.wkWebView loadRequest:request]; } #pragma mark - 懒加载 - (UIView *)bottomView { if (_bottomView == nil) { UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, kScreenHeight - kBottomViewH, kScreenWidth, kBottomViewH)]; view.backgroundColor = [UIColor colorWithRed:230/255.0 green:230/255.0 blue:230/255.0 alpha:1]; [self.view addSubview:view]; _bottomView = view; } return _bottomView; } - (UISearchBar *)searchBar { if (_searchBar == nil) { UISearchBar *searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 20, kScreenWidth, kSearchBarH)]; searchBar.delegate = self; searchBar.text = @"http://www.cnblogs.com/mddblog/"; _searchBar = searchBar; } return _searchBar; } - (WKWebView *)wkWebView { if (_wkWebView == nil) { WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectMake(0, 20 + kSearchBarH, kScreenWidth, kScreenHeight - 20 - kSearchBarH - kBottomViewH)]; webView.navigationDelegate = self; // webView.scrollView.scrollEnabled = NO; // webView.backgroundColor = [UIColor colorWithPatternImage:self.image]; // 允许左右划手势导航,默认允许 webView.allowsBackForwardNavigationGestures = YES; _wkWebView = webView; } return _wkWebView; } @end
五、github代码下载