iOS WKWebView 点击超链接跳转至Safari

-(void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {
    //1.拦截请求
    NSString *urlString = [navigationAction.request.URL absoluteString];
    //    2.跳转别的应用如系统浏览器（跨域跳转）、应用的web内跳转（不跨域跳转）
    NSString *hostname = navigationAction.request.URL.host.lowercaseString;
    if (navigationAction.navigationType == WKNavigationTypeLinkActivated) {//跳转别的应用如系统浏览器
        // 对于跨域，需要手动跳转
        [[UIApplication sharedApplication] openURL:navigationAction.request.URL];
        // 不允许web内跳转
        decisionHandler(WKNavigationActionPolicyCancel);
    } else {//应用的web内跳转
        decisionHandler (WKNavigationActionPolicyAllow);
    }
    return ;
}