1.UIWebView的优缺点

<1>UIWebView由于系统本身存在的问题可能导致内存泄漏；
<2>UIWebView支持缓存和NSURLProtocol 拦截;
<3>用UIWebView加载大数据资源时，内存峰值、内存都会暴增，同时CPU电量消耗也较高.

2.WKWebView的优缺点

<1>WKWebView网页加载速度有提升，更快（占用内存可能只有 UIWebView 的1/3~1/4)；
<2>提供加载网页进度的属性;
<3>没有缓存，对UIWebViewDelegate中的方法拆分的更为细致了，如果对于缓存不是很高的页面，可以采用WKWebView,能够有更好的用户体验;
<4>WKWebView不支持缓存和NSURLProtocol 拦截;
<5>拥有高达60FPS滚动刷新率及内置手势;
<6>高效的app和web信息交换通道

3.WKWebView常用API

容器相关

//配置
@property (nonatomic, readonly, copy) WKWebViewConfiguration *configuration;
//页面标题，支持KVO
@property (nullable, nonatomic, readonly, copy) NSString *title;
//当前请求的URL,支持KVO
@property (nullable, nonatomic, readonly, copy) NSURL *URL;
//标识是否正在加载内容中，支持KVO
@property (nonatomic, readonly, getter=isLoading) BOOL loading;
//当前加载的进度,范围为[0,1]
@property (nonatomic, readonly) double estimatedProgress;
//标识当前页面中所有资源是否通过安全加密连接来加载,支持KVO
@property (nonatomic, readonly) BOOL hasOnlySecureContent;
//是否可以执行GoBack操作，支持KVO
@property (nonatomic, readonly) BOOL canGoBack;
//是否可以执行GoFoward操作,支持KVO
@property (nonatomic, readonly) BOOL canGoForward;
//返回上一页，如果不能返回，则什么也不干
- (nullable WKNavigation *)goBack;
//进入下一页，如果不进入，则什么也不干
- (nullable WKNavigation *)goForward;
//重新载入界面
- (nullable WKNavigation *)reload;
//重新从原始的URL载入界面
- (nullable WKNavigation *)reloadFromOrigin;
//停止加载数据
- (void)stopLoading;
//执行JS代码
- (void)evaluateJavaScript:(NSString *)javaScriptString completionHandler:(void (^ __nullable)(__nullable id, NSError * __nullable error))completionHandler;

页面加载相关

//从request加载资源
- (nullable WKNavigation *)loadRequest:(NSURLRequest *)request;
//从本地文件加载(只支持IOS9.0以上)
- (nullable WKNavigation *)loadFileURL:(NSURL *)URL allowingReadAccessToURL:(NSURL *)readAccessURL 
//从HTML字符串加载
- (nullable WKNavigation *)loadHTMLString:(NSString *)string baseURL:(nullable NSURL *)baseURL;
//从二进制数据流中加载
- (nullable WKNavigation *)loadData:(NSData *)data MIMEType:(NSString *)MIMEType characterEncodingName:(NSString *)characterEncodingName baseURL:(NSURL *)baseURL NS_AVAILABLE(10_11, 9_0);

代理相关

//在发送请求之前，决定是否跳转
- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler;
//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
- (void)webView:(WKWebView *)webView decidePolicyForNavigationResponse:(WKNavigationResponse *)navigationResponse decisionHandler:(void (^)(WKNavigationResponsePolicy))decisionHandler;
//接收到服务器跳转请求后调用（服务器端redirect）,不一定调用
- (void)webView:(WKWebView *)webView didReceiveServerRedirectForProvisionalNavigation:(null_unspecified WKNavigation *)navigation;
//页面内容加载失败
- (void)webView:(WKWebView *)webView didFailProvisionalNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error;
//开始获取到网页的内容
- (void)webView:(WKWebView *)webView didCommitNavigation:(null_unspecified WKNavigation *)navigation;
//页面加载完成
- (void)webView:(WKWebView *)webView didFinishNavigation:(null_unspecified WKNavigation *)navigation;
//页面加载失败
- (void)webView:(WKWebView *)webView didFailNavigation:(null_unspecified WKNavigation *)navigation withError:(NSError *)error;
//SSL认证
- (void)webView:(WKWebView *)webView didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge completionHandler:(void (^)(NSURLSessionAuthChallengeDisposition disposition, NSURLCredential *__nullable credential))completionHandler;
//页面内容完全加载完
- (void)webViewWebContentProcessDidTerminate:(WKWebView *)webView NS_AVAILABLE(10_11, 9_0);

上面只是简单介绍了一下WKWebView的常用方法，如果还有进一步的需求，请参考http://www.jianshu.com/p/90a90bd13aac ，或者私信我，微信号1395258209.