1:youtube player可以通过id 或url来播放视频

主要用到的两个方法是 loadWithVideoId 和 loadVideoByURL

这两者的区别是 loadVideoByURL加载完之后会自动播放的

loadWithVideoId不会自动播放 加载完之后会显示第一政的图和一个播放按钮

2：通过url获取id的重点实现方法如下：

private extension NSURL {
func queryStringComponents() -> [String: AnyObject] {

var dict = [String: AnyObject]()

// Check for query string
if let query = self.query {

// Loop through pairings (separated by &)
for pair in query.componentsSeparatedByString("&") {

// Pull key,val from from pair parts (separated by =) and set dict[key] = value
let components = pair.componentsSeparatedByString("=")
if (components.count > 1) {
dict[components[0]] = components[1]
}
}

}

return dict
}
}

public func videoIDFromYouTubeURL(videoURL: NSURL) -> String? { if let host = videoURL.host,pathComponents = videoURL.pathComponents where pathComponents.count > 1 && host.hasSuffix("youtu.be") { return pathComponents[1] } return videoURL.queryStringComponents()["v"] as? String }