将图像设置为UITableViewCell背景无法正常工作

Question

我正在尝试将图像设置为'UITableView cell background.I create UIiImageView in cellforRowAt` func并将其添加到单元格作为subView，但结果是：

仅适用于第一个细胞。我在cellForRowAt函数中的代码：

 let imageView =  UIImageView(frame: CGRect(x: cell.frame.origin.x - 10  , y: cell.frame.origin.y - 20 , width: cell.frame.size.width + 20 , height: cell.frame.size.height ))
 let image = UIImage(named: "sentimg")
 imageView.image = image
 cell.backgroundView = UIView()
 cell.backgroundView!.addSubview(imageView)

Answer 1

您应该在cell.bounds中使用cell.frame代替let imageView = UIImageView(frame: CGRect(x: cell.frame.origin.x - 10 , y: cell.frame.origin.y - 20 , width: cell.frame.size.width + 20 , height: cell.frame.size.height ))，cell.frame将在其superView中引用该单元格的位置，而cell.bounds将引用该位置相对于它自己，这就是你需要的，因为你将你的图像添加为细胞子视图

类似

 let imageView =  UIImageView(frame: CGRect(x: cell.bounds.origin.x - 10  , y: cell.bounds.origin.y - 20 , width: cell.bounds.size.width + 20 , height: cell.bounds.size.height ))`

Answer 2

或者更好的是，使用自动布局约束：

let imageView = UIImageView(image: UIImage(named: "sentimg"))
let backgroundView = UIView()
imageView.translatesAutoresizingMaskIntoConstraints = false
NSLayoutConstraint.activate([
    imageView.leftAnchor.constraint(equalTo: backgroundView.leftAnchor, constant: -10),
    imageView.rightAnchor.constraint(equalTo: backgroundView.rightAnchor, constant: 10),
    imageView.topAnchor.constraint(equalTo: backgroundView.topAnchor, constant: -20),
    imageView.bottomAnchor.constraint(equalTo: backgroundView.bottomAnchor, constant: -20),
    ])

cell.backgroundView = backgroundView