介绍
WWDC2014推出ios8，其中webkit对应的WKWebView相对于uiwebview更加强大，内存、加载速度更优。
- 在性能、稳定性、功能方面有很大提升
- 允许JavaScript的Nitro库加载并使用（UIWebView中限制）
- 支持了更多的HTML5特性
- 高达60fps的滚动刷新率以及内置手势
- 将UIWebViewDelegate与UIWebView重构成了14类与3个协议
环境
Mac OS X 10.10.1
Xcode 6.1.1
iOS 8.1
初始化
#import <WebKit/WebKit.h>
// 默认初始化
- (instancetype)initWithFrame:(CGRect)frame;
// 根据对webview的相关配置，进行初始化
- (instancetype)initWithFrame:(CGRect)frame configuration:(WKWebViewConfiguration *)configuration NS_DESIGNATED_INITIALIZER;
//加载网页
WKWebView *webView = [[WKWebView alloc] initWithFrame:self.view.bounds];
[webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.baidu.com"]]];
[self.view addSubview:webView];
WKWebView的代理方法
WKWebView的代理方法
WKNavigationDelegate
// 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
// 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;
执行顺序：
webView:decidePolicyForNavigationAction:decisionHandler(如果拒绝则后续无其他回调)
webView:didStartProvisionalNavigation
webView:decidePolicyForNavigationResponse:decisionHandler(如果拒绝则收到error回调)
webView:didCommitNavigation
webView:didFinishNavigation
2. WKUIDelegate
// 创建一个新的WebView
- (WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures;
//警告框、确认框、输入框
/**
* 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 frame 主窗口
* @param completionHandler 警告框消失调用
*/
- (void)webView:(WKWebView *)webView runJavaScriptAlertPanelWithMessage:(NSString *)message initiatedByFrame:(void (^)())completionHandler;
3. WKScriptMessageHandler
提高App与web端交互, 将接收到的JS脚本转为OC或Swift对象
// 从web界面中接收到一个脚本时调用
- (void)userContentController:(WKUserContentController *)userContentController didReceiveScriptMessage:(WKScriptMessage *)message;
4.WKWebView加载JS
// 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>" baseURL:nil];
[self.view addSubview:_webView];
