applicationDidFinishLaunching 不会被触发

Question

试图了解我在使用以下代码时犯了什么错误。 这是一个 Mac 应用程序，Xcode 版本 12.4。我的问题是 applicationDidFinishLaunching 永远不会被触发。

import SwiftUI

@main
struct TestApp: App {
    @NSApplicationDelegateAdaptor(AppDelegate.self) var Delegate
    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}


class AppDelegate: NSObject, NSApplicationDelegate {
    func applicationDidFinishLaunching(aNotification: NSNotification) {
        let alert = NSAlert.init()
        alert.messageText = "Hello world"
        alert.informativeText = "Information text"
        alert.addButton(withTitle: "OK")
        alert.addButton(withTitle: "Cancel")
        alert.runModal()
    }
}

Answer 1

您输入错误。不是“a”而是“_”

#include <iostream>
using namespace std;
int main(){
int a=68;
cout<<char(a);
char c='D';
cout<<int(c);
return 0;
}