Swift5.0 -系统分享UIActivity

iOS自带的分享控件其实是一个很nice的。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。还有更多的分享不需要我们去设置。

两个步骤即可完成

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

一、具体的支持的分享类型

extension UIActivity.ActivityType {

    @available(iOS 6.0, *)
    public static let postToFacebook: UIActivity.ActivityType

    @available(iOS 6.0, *)
    public static let postToTwitter: UIActivity.ActivityType

    @available(iOS 6.0, *)
    public static let postToWeibo: UIActivity.ActivityType

    @available(iOS 6.0, *)
    public static let message: UIActivity.ActivityType

    @available(iOS 6.0, *)
    public static let mail: UIActivity.ActivityType

    @available(iOS 6.0, *)
    public static let print: UIActivity.ActivityType

    @available(iOS 6.0, *)
    public static let copyToPasteboard: UIActivity.ActivityType

    @available(iOS 6.0, *)
    public static let assignToContact: UIActivity.ActivityType

    @available(iOS 6.0, *)
    public static let saveToCameraRoll: UIActivity.ActivityType

    @available(iOS 7.0, *)
    public static let addToReadingList: UIActivity.ActivityType

    @available(iOS 7.0, *)
    public static let postToFlickr: UIActivity.ActivityType

    @available(iOS 7.0, *)
    public static let postToVimeo: UIActivity.ActivityType

    @available(iOS 7.0, *)
    public static let postToTencentWeibo: UIActivity.ActivityType

    @available(iOS 7.0, *)
    public static let airDrop: UIActivity.ActivityType

    @available(iOS 9.0, *)
    public static let openInIBooks: UIActivity.ActivityType

    @available(iOS 11.0, *)
    public static let markupAsPDF: UIActivity.ActivityType
}

二、UIActivity配置分享的内容和链接等

1.如果不需要自定义的分享，直接设置UIActivity（这里不在细说，下面的用法里就有）

2.自定义的LGActivity

class LGActivity: UIActivity {
    
    let LGActivityType =  "LGActivityType"
    
    var lgTitle: String?
    var lgImage: UIImage?
    var lgUrl: URL?
    var lgShareContexts: [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()
        lgTitle = title
        lgImage = image
        if url != nil {
           lgUrl = url
        }
        lgShareContexts = 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 value
    override var activityImage: UIImage? {
        return lgImage
    }
    
    // default returns nil. subclass must override and must return non-nil value
    override var activityTitle: String? {
        return lgTitle
    }
    
    var activityUrl: URL? {
        return lgUrl
    }
    
    // default returns nil. subclass may override to return custom activity type that is reported to completion handler
    override var activityType: UIActivity.ActivityType? {
        return UIActivity.ActivityType(rawValue: LGActivityType)
    }
    
    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)
    }
}

三、UIActivityViewController弹出视图

class LGSystemShare: NSObject {
    
    var parentVc: UIViewController?

    static let manager = LGSystemShare()
    private override init() {
        super.init()
    }
    ///这里我设置了配置链接是可选的
    func lgShrare(shreVC: UIViewController, orText: String, trText: String, shareUrl: URL?) {
        parentVc = shreVC
        var activityItems = [Any]()
        if shareUrl == nil {
            activityItems = [orText, trText]
        } else {
            activityItems = [orText, trText,  shareUrl as Any]
        }
        let activity = LGActivity(title: lg_appName, 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 = true
        shreVC.present(activityVC, animated: true, completion: nil)
    }
}

到此，基本的系统分享已完成，需要更复杂的分享，各位可以继续深入研究！！！