UIWebView加载的H5，可以调用；但是WKWebView就是不行，可以在WKWebView的WKNavigationDelegate代理方法处理，代码如下：
// 处理拨打电话以及Url跳转等等
- (void)webView:(WKWebView*)webView decidePolicyForNavigationAction:(WKNavigationAction*)navigationAction decisionHandler:(void(^)(WKNavigationActionPolicy))decisionHandler {
NSURL*URL = navigationAction.request.URL;
NSString*scheme = [URLscheme];
if([schemeisEqualToString:@"tel"]) {
NSString*resourceSpecifier = [URLresourceSpecifier];
NSString*callPhone = [NSStringstringWithFormat:@"telprompt://%@", resourceSpecifier];
/// 防止iOS 10及其之后，拨打电话系统弹出框延迟出现
dispatch_async(dispatch_get_global_queue(0, 0), ^{
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:callPhone]];
});
}
decisionHandler(WKNavigationActionPolicyAllow);
}
