如何将 Objective-C App Delegate 转换为 Swift？

Question

我正在处理旧项目，将所有 classes 转换为 Swift。

如何将 AppDelegate class 转换为 Swift？

我必须在项目设置或 main.m 中进行哪些更改？

Answer 1

一个好的起点是创建一个新的 Swift-Project 以获得 AppDelegate 的模板，或者只需将以下代码复制到您的 AppDelegate.swift class:

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        // Override point for customization after application launch.
        return true
    }
    
    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
    }
    
    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }
    
    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }
    
    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }
    
    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground.
    }
}

在 Swift 中，main.m 和 AppDelegate class 已通过使用 @UIApplicationMain 注释合并。因此，不再需要 main.m，应将其从您的项目中删除。

也不需要更改您的项目设置，因此 @UIApplicationMain 会为您完成这项工作。如果您有更多具有不同 AppDelegates.

的构建目标，请务必设置正确的 AppDelegate class 目标成员资格

Answer 2

在 Xcode 中创建一个新文件（文件 > 新建 > 文件…）和 select a Cocoa 触摸 Class。将其命名为 AppDelegate，使其成为 UIResponder 的子类并将语言更改为 Swift.

用以下内容填充 AppDelegate.swift 文件：

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?

    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions:     NSDictionary?) -> Bool {
        // Override point for customization after application launch.

        return true
    }
}

删除您的 main.m 和 main.h 文件。

完成！

来源：http://www.binpress.com/tutorial/converting-an-objective-c-app-to-swift/118

Answer 3

为了改进@seeya

SWIFT 3

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
        // Override point for customization after application launch.
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
        // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
        // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
        // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
        // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
        // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
    }

    func applicationWillTerminate(_ application: UIApplication) {
        // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
    }

}

Answer 4

None 以前的答案对我有用，经过一些研究，这个有效：

import Foundation

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
  var window: UIWindow?
  var bridge: RCTBridge!

  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    let jsCodeLocation: URL

    jsCodeLocation = RCTBundleURLProvider.sharedSettings().jsBundleURL(forBundleRoot: "index.ios", fallbackResource:nil)
    let rootView = RCTRootView(bundleURL: jsCodeLocation, moduleName: "REPLACE_BY_YOUR_PROJECT_NAME", initialProperties: nil, launchOptions: launchOptions)
    let rootViewController = UIViewController()
    rootViewController.view = rootView

    self.window = UIWindow(frame: UIScreen.main.bounds)
    self.window?.rootViewController = rootViewController
    self.window?.makeKeyAndVisible()



    return true
  }
}

Answer 5

粘贴上述答案的解决方案，导致 Xcode 建议更新函数声明以将其标记为 private。在这种情况下，该函数将不会被系统调用，您的应用将永远不会启动。

Swift 5

使用AppDelegate.swift如下：

import UIKit

@main
class AppDelegate: UIResponder, UIApplicationDelegate {
    var window: UIWindow?
    
    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
        let rootViewController = UIViewController() // replace with your view controller
        window = UIWindow(frame: UIScreen.main.bounds)
        window?.rootViewController = rootViewController
        window?.makeKeyAndVisible()
        return true
    }
}

如何将 Objective-C App Delegate 转换为 Swift？

How to convert Objective-C App Delegate to Swift?

objective-c

ios

appdelegate

swift