iPhone 应用程序使用什么 dpi 分辨率

swift
import UIKit
class ViewController: UIViewController {
    @IBOutlet weak var imageView: UIImageView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 设置图片
        let image = UIImage(named: "example_image")
        imageView.image = image
        imageView.contentMode = .scaleAspectFit
    }
}