UITableViewController上的渐变背景swift

Question

我将两种颜色的背景应用于tableview。当后台表加载数据表时，仅加载一个插入，不加载其他数据。因此，在运行后台功能时，它只会安装一个表行，而不会加载其他表行

extension UIView {

    func setGradientBackground(sender: UITableViewController, colorOne: UIColor, colorTwo: UIColor) {

        let gradientLayer = CAGradientLayer()

        gradientLayer.frame = sender.view.bounds
        gradientLayer.colors = [colorOne.cgColor, colorTwo.cgColor]
        gradientLayer.locations = [0.0, 1.0]
        gradientLayer.startPoint = CGPoint(x: 0.0, y: 1.0)
        gradientLayer.endPoint = CGPoint(x: 1.0, y: 0.0)
        layer.insertSublayer(gradientLayer, at: 0)


    } }

我在这里运行桌子

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath) as! DeviceTableViewCell

         cell.setGradientBackground(sender: self, colorOne: Colors.brightOrange, colorTwo: Colors.darkGrey)
        let deviceItem: Device = items[indexPath.row]

        cell.deviceItem = deviceItem
        cell.title.text = deviceItem.title
        cell.title1.text = deviceItem.places
        cell.titlesaat.text = deviceItem.time
        cell.button.isOn = deviceItem.state
        tablerow = String (indexPath.row)
        return cell
    }