Ilya Falko's questions

有两种代码变体，其中秒表以不同的方式测量经过的时间。我不明白为什么。这是代码 -

1.第一个例子（在AsyncAction方法中，同步部分在前，然后是异步部分）-

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace DifferentTasks
{
    public class SyncAndAsyncPartsOfMethod
    {
        public async Task Execute()
        {
            IEnumerable<int> data = Enumerable.Range(0, 100);

            Stopwatch stopwatch = Stopwatch.StartNew();

            Task t = Task.WhenAll(data.Select(AsyncAction));
            await t;
            stopwatch.Stop();

            double elapsedSeconds = TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds;

            Console.WriteLine("Elapsed seconds overall - " + elapsedSeconds);
        }
        
        private async Task AsyncAction(int x)
        {
            Stopwatch stopwatch = Stopwatch.StartNew();
            
            Thread.Sleep(TimeSpan.FromSeconds(1));
            await Task.Delay(TimeSpan.FromSeconds(1)); 
            
            stopwatch.Stop();
                
            double elapsedSeconds = TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds;
                
            Console.WriteLine($"AsyncAction {x} is finished, elapsed seconds - {elapsedSeconds}, thread - {Thread.CurrentThread.ManagedThreadId}");
        }
    }
}

结论：总经过秒数 - 102 秒

AsyncAction 方法中的秒表显示该方法每次运行正好两秒：

AsyncAction 95 is finished, elapsed seconds - 2,046, thread - 5
AsyncAction 96 is finished, elapsed seconds - 2,032, thread - 4
AsyncAction 97 is finished, elapsed seconds - 2,015, thread - 4
AsyncAction 98 is finished, elapsed seconds - 2,029, thread - 4
AsyncAction 99 is finished, elapsed seconds - 2,046, thread - 5

2.第二个例子（在AsyncAction方法中，异步部分在前，然后是同步部分）-

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;

namespace DifferentTasks
{
    public class SyncAndAsyncPartsOfMethod
    {
        public async Task Execute()
        {
            IEnumerable<int> data = Enumerable.Range(0, 100);

            Stopwatch stopwatch = Stopwatch.StartNew();

            Task t = Task.WhenAll(data.Select(AsyncAction));
            await t;
            stopwatch.Stop();

            double elapsedSeconds = TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds;

            Console.WriteLine("Elapsed seconds overall - " + elapsedSeconds);
        }
        
        private async Task AsyncAction(int x)
        {
            Stopwatch stopwatch = Stopwatch.StartNew();
            
            await Task.Delay(TimeSpan.FromSeconds(1)); 
            Thread.Sleep(TimeSpan.FromSeconds(1));
            
            stopwatch.Stop();
                
            double elapsedSeconds = TimeSpan.FromMilliseconds(stopwatch.ElapsedMilliseconds).TotalSeconds;
                
            Console.WriteLine($"AsyncAction {x} is finished, elapsed seconds - {elapsedSeconds}, thread - {Thread.CurrentThread.ManagedThreadId}");
        }
    }
}

结论：总经过秒数 - 13 秒

AsyncAction 方法中的秒表现在显示 AsyncAction 方法每次执行所需的时间更长 -

AsyncAction 92 is finished, elapsed seconds - 3,066, thread - 6
AsyncAction 89 is finished, elapsed seconds - 4,035, thread - 8
AsyncAction 87 is finished, elapsed seconds - 4,082, thread - 6
AsyncAction 85 is finished, elapsed seconds - 4,082, thread - 5
AsyncAction 83 is finished, elapsed seconds - 5,051, thread - 8
AsyncAction 81 is finished, elapsed seconds - 5,067, thread - 4

启动这些课程的代码 -

using System;
using System.Runtime.InteropServices;

namespace DifferentTasks
{
    internal class Program
    {
        public static void Main(string[] args)
        {
            SyncAndAsyncPartsOfMethod syncAndAsyncPartsOfMethod = new();
            syncAndAsyncPartsOfMethod.Execute().Wait();
            Console.ReadLine();
        }
    }
}

我想了解为什么 -

1. 根据是先执行异步部分还是先执行同步部分，总运行时间会有所不同
2. 为什么先执行异步部分，方法的执行时间每次都会增加。

如何在不同类的相同 Canvas 上绘图？问题是当从不同的类访问画布时，会返回不同的引用。

加载应用程序的主类：

@FXML
public Canvas game = new Canvas(WIDTH, HEIGHT);
//Объект для взаимодействия с классом.
public static GameController gamecontroller = new GameController();
//Графический контекст, из которого я рисую
public GraphicsContext gc = this.getGraphicsContext();
public void initialize(URL url, ResourceBundle resourceBundle) {
    System.out.println("Game was loaded");
    gc = getGraphicsContext(); //{return draw.getGraphicsContext2D;}
    gc.setFill(Color.BLACK);
    gc.fillRect(0,0,WIDTH,HEIGHT);
    Handler.handler.addGameObject(new Player(30.0, 30.0, Id.player)); //Добавляю объект на сцену
    Handler.handler.render(); //Рисую его
}
public GraphicsContext getGraphicsContext()
{
    return game.getGraphicsContext2D();
}

我还有一个 GameObject 类，游戏对象类是从该类继承而来的，例如 Player。游戏对象：

public static GraphicsContext draw
        = GameController.gamecontroller.getGraphicsContext(); 

玩家：

public void render() {
    draw.setFill(Color.WHITE);
    draw.fillRect(10,10,16,16);
}

也就是说，render() 方法可以工作，但 Canvas 上没有显示任何内容，由于某种原因，当访问一个对象（或访问一个返回值的函数时）时，会返回对它的不同引用。