创建一个完整的APP需要涉及多个文件和多种技术，且具体实现会根据所选的平台（如iOS、Android、Web等）和技术栈（如React Native、Flutter、Swift、Kotlin等）有所不

Swift (iOS)qianqutech.com swift import UIKit

@UIApplicationMain class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

window = UIWindow(frame: UIScreen.main.bounds)

window?.rootViewController = UIViewController()

window?.makeKeyAndVisible()

return true

}

} 2. Kotlin (Android) kotlin import android.os.Bundle import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState) setContentView(R.layout.activity_ma