iOS自带的分享控件可以完成绝大部分的分享需求。
它可以不需要集成微信、QQ等第三方SDK就可以实现分享（需要在弹出视图里面点击更多打开开关）到微信好友、朋友圈等,功能很强大，也很方便。

一、系统分享两个步骤

1. UIActivity配置分享的内容和链接、操作（自定义）
2. UIActivityViewController弹出分享视图

1. UIActivity配置分享的内容和链接等

自定义的GXActivity

class GXActivity: UIActivity {private let kActivityType =  "kActivityType"private var text: String?private var img: UIImage?private var url: URL?private var shareContexts: [Any]?// 设置title  和 image会在弹出视图里面出现一个自定义的应用，// title为应用名称  image为应用图标  shareContext是存放分享的内容的convenience init(title: String?, image: UIImage?, url: URL?, shareContext: [Any]) {self.init()self.text = titleself.img = imageif url != nil {self.url = url}self.shareContexts = shareContext}override init() {super.init()}// default is UIActivityCategoryAction.override class var activityCategory: UIActivity.Category {return .share}// default returns nil. subclass must override and must return non-nil valueoverride var activityImage: UIImage? {return img}// default returns nil. subclass must override and must return non-nil valueoverride var activityTitle: String? {return text}var activityUrl: URL? {return url}// default returns nil. subclass may override to return custom activity type that is reported to completion handleroverride var activityType: UIActivity.ActivityType? {return UIActivity.ActivityType(rawValue: kActivityType)}override func canPerform(withActivityItems activityItems: [Any]) -> Bool {if activityItems.count > 0 {return true}return false}// 准备分享所进行的方法，通常在这个方法里面，把item中的东西保存下来,items就是要传输的数据override func prepare(withActivityItems activityItems: [Any]) {print("activityItems --- \(activityItems)")}override func perform() {// 在这里写你自定义的应用 分享点击以后需要做的操作，比如点击需要打开链接、复制等等self.activityDidFinish(true)}
}

UIActivityViewController弹出视图

class GXSystemShare: NSObject {public var parentVC: UIViewController?public static let manager = GXSystemShare()private override init() {super.init()}/// 这里我设置了配置链接是可选的func shrare(shareVC: UIViewController, orText: String, trText: String, shareUrl: URL? = nil) {parentVC = shareVCvar activityItems = [Any]()if shareUrl == nil {activityItems = [orText, trText]} else {activityItems = [orText, trText, shareUrl as Any]}let activity = GXActivity(title: "Demo AP", image: UIImage(named: "iPhoneApp.png"), url: shareUrl, shareContext: activityItems)let activityVC = UIActivityViewController(activityItems: activityItems, applicationActivities: [activity])// 表示去掉不想显示的按钮  即第一点里面所包含的type 放到这里activityVC.excludedActivityTypes = []//        activityVC.isModalInPopover = trueshareVC.present(activityVC, animated: true, completion: nil)}
}