URLSessionfetchData.swift

func fetchData() {
  //使用URLSession來抓取需要的資料
        let urlStr = "https://www.instagram.com/scottcbakken/?__a=1"
        if let url = URL(string: urlStr) {
            URLSession.shared.dataTask(with: url) { (data, response, error) in
                let decoder = JSONDecoder()
                decoder.dateDecodingStrategy = .secondsSince1970
                if let data = data,
                   let renderData = try? decoder.decode(InstagramData.self, from: data) {
                    self.igdata = renderData
                    self.igposts = renderData.graphql.user.edge_owner_to_timeline_media.edges
                    DispatchQueue.main.async {
                        self.collectionView.reloadData()
                    }
                }
            }.resume()
        }
    }