C# 线程问题 如何在子线程中调用方法，使这个方法为主线程执行的

Question

如下，如何在task1这个线程中，通过委托给主线程来调用ThreadToMain这个方法
使输出为(顺序不重要）：
执行主线程！1
hello, task2的线程ID为4
hello, task1的线程ID为3
调用这个程序的线程ID为1

using System;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Program
    {
        public delegate void DelegateFun();

        static void Main(string[] args)
        {
            DelegateFun c = new DelegateFun(ThreadToMain);

            void ThreadToMain()
            {
                Console.Write("ThreadToMain");
                Console.WriteLine($"的线程ID为{Thread.CurrentThread.ManagedThreadId}");
            }
            //1.new方式实例化一个Task，需要通过Start方法启动
            Task task1 = new Task(() =>
            {
                Thread.Sleep(100);
                Console.WriteLine($"hello, task1的线程ID为{Thread.CurrentThread.ManagedThreadId}");
                c.Invoke();
            });
            task1.Start();

            //2.Task.Factory.StartNew(Action action)创建和启动一个Task
            Task task2 = Task.Factory.StartNew(() =>
            {
                Thread.Sleep(100);
                Console.WriteLine($"hello, task2的线程ID为{ Thread.CurrentThread.ManagedThreadId}");
            });

            Console.Write("执行主线程！");
            Console.WriteLine(Thread.CurrentThread.ManagedThreadId);
 
            Console.ReadKey();
        }
    }
}

Answer 1

控制台程序没搞，winform/wf可以用this.invoke切换到UI线程，控制台程序没有this无invoket方法。要实现需要做大量的改动，一下内容来自Stack Overflow

https://stackoverflow.com/questions/12285180/continue-task-on-main-thread

You can't do this (without a lot of work) in a Console application. The mechanisms built into the TPL for marshaling the call back onto a thread all rely on the thread having an installed SynchronizationContext. This typically gets installed by the user interface framework (ie: Application.Run in Windows Forms, or in WPF's startup code, etc).

可以使用wait等待task1执行完毕后再执行ThreadToMain方法，有帮助或启发麻烦点个采纳【本回答右上角】，谢谢~~

using System;
using System.Threading;
using System.Threading.Tasks;
namespace ConsoleApp1
{
    class Program
    {
        public delegate void DelegateFun();
        static void Main(string[] args)
        {
            DelegateFun c = new DelegateFun(ThreadToMain);
            void ThreadToMain()
            {
                Console.Write("ThreadToMain");
                Console.WriteLine($"的线程ID为{Thread.CurrentThread.ManagedThreadId}");
            }
            //1.new方式实例化一个Task，需要通过Start方法启动
            Task task1 = new Task(() =>
            {
                Thread.Sleep(100);
                Console.WriteLine($"hello, task1的线程ID为{Thread.CurrentThread.ManagedThreadId}");
                //c.Invoke();
            });
            task1.Start();
            task1.Wait();//////////////

            c.Invoke();//////////放在这里执行
            //2.Task.Factory.StartNew(Action action)创建和启动一个Task
            Task task2 = Task.Factory.StartNew(() =>
            {
                Thread.Sleep(100);
                Console.WriteLine($"hello, task2的线程ID为{ Thread.CurrentThread.ManagedThreadId}");
            });
            Console.Write("执行主线程！");
            Console.WriteLine(Thread.CurrentThread.ManagedThreadId);
            Console.ReadKey();
        }
    }
}