wkwebview 怎么调用js方法

//直接调用js
//webView.evaluateJavaScript("hi()", completionHandler: nil)
//调用js带参数
//webView.evaluateJavaScript("hello('')", completionHandler: nil)
//调用js获取返回值
//webView.evaluateJavaScript("getName()") { (any,error) -> Void in
//    NSLog("%@", any as! String)
//}
- (void)hello:(NSString *)param{
    [self showAlert:param Title:@"js Call iOS"];
}