iOS开发中，在UIWebView中添加手势的方法如下
// 监控界面点击手势
let singleTap = UITapGestureRecognizer(target: self, action: "singleTapAction:")
// 注意：不做如下处理，无法监控到单击手势
singleTap.cancelsTouchesInView = false
singleTap.delegate = self
self.webView.addGestureRecognizer(singleTap)
协议实现：
// MARK: - UIGestureRecognizerDelegate
func gestureRecognizer(gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWithGestureRecognizer otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}
