ソースコード

import UIKit

class InstaStories: NSObject {
    
    private let urlScheme = URL(string: "instagram-stories://share")!
    
    enum optionsKey: String {
        case stickerImage = "com.instagram.sharedSticker.stickerImage"
        case bgImage = "com.instagram.sharedSticker.backgroundImage"
        case bgVideo = "com.instagram.sharedSticker.backgroundVideo"
        case bgTopColor = "com.instagram.sharedSticker.backgroundTopColor"
        case bgBottomColor = "com.instagram.sharedSticker.backgroundBottomColor"
        case contentUrl = "com.instagram.sharedSticker.contentURL"
    }
    
    /// 背景画像を投稿
    func post(bgImage:UIImage, stickerImage:UIImage? = nil, contentURL:String? = nil) -> Bool{
        var items:[[String : Any]] = [[:]]
        //Background Image
        let bgData = UIImagePNGRepresentation(bgImage)
        items[0].updateValue(bgData, forKey: optionsKey.bgImage.rawValue)
        //Sticker Image
        if stickerImage != nil {
            guard let stickerImage = stickerImage else { return false }
            let stickerData = UIImagePNGRepresentation(stickerImage)
            items[0].updateValue(stickerData, forKey: optionsKey.stickerImage.rawValue)
        }
        //Content URL
        if contentURL != nil {
            items[0].updateValue(contentURL as Any, forKey: optionsKey.contentUrl.rawValue)
        }
        let isPosted = post(items)
        return isPosted
    }
    
    /// 背景動画を投稿
    func post(bgVideoUrl:URL, stickerImage:UIImage? = nil, contentURL:String? = nil) -> Bool{
        var items:[[String : Any]] = [[:]]
        //Background Video
        var videoData:Data?
        do {
            try videoData = Data(contentsOf: bgVideoUrl)
        } catch {
            print("Cannot open \(bgVideoUrl)")
            return false
        }
        items[0].updateValue(videoData as Any, forKey: optionsKey.bgVideo.rawValue)
        //Sticker Image
        if stickerImage != nil {
            guard let stickerImage = stickerImage else { return false }
            let stickerData = UIImagePNGRepresentation(stickerImage)
            items[0].updateValue(stickerData, forKey: optionsKey.stickerImage.rawValue)
        }
        //Content URL
        if contentURL != nil {
            items[0].updateValue(contentURL as Any, forKey: optionsKey.contentUrl.rawValue)
        }
        let isPosted = post(items)
        return isPosted
    }
    
    /// ステッカー画像を投稿
    func post(stickerImage:UIImage, bgTop:String = "#FFFFFF", bgBottom:String = "#FFFFFF", contentURL:String? = nil) -> Bool{
        var items:[[String : Any]] = [[:]]
        //Sticker Image
        let stickerData = UIImagePNGRepresentation(stickerImage)
        items[0].updateValue(stickerData, forKey: optionsKey.stickerImage.rawValue)
        //Background Color
        items[0].updateValue(bgTop, forKey: optionsKey.bgTopColor.rawValue)
        items[0].updateValue(bgBottom, forKey: optionsKey.bgBottomColor.rawValue)
        //Content URL
        if contentURL != nil {
            items[0].updateValue(contentURL as Any, forKey: optionsKey.contentUrl.rawValue)
        }
        let isPosted = post(items)
        return isPosted
    }
    
    /// Instagram Storiesへ投稿
    private func post(_ items:[[String : Any]]) -> Bool{
        guard UIApplication.shared.canOpenURL(urlScheme) else {
            print("Cannot open \(urlScheme)")
            return false
        }
        let options: [UIPasteboard.OptionsKey: Any] = [.expirationDate: Date().addingTimeInterval(60 * 5)]
        UIPasteboard.general.setItems(items, options: options)
        UIApplication.shared.open(urlScheme)
        return true
    }
    
}

// Singleton
extension InstaStories {
    class var Shared : InstaStories {
        struct Static { static let instance : InstaStories = InstaStories() }
        return Static.instance
    }
}

使用方法

guard let url = URL(string: imageUrl) else { return }
let imageView = UIImageView()
imageView.af_setImage(withURL: url)
guard let postImage = imageView.image else { return }
InstaStories.Shared.post(stickerImage: postImage, contentURL: shareUrl)