使用案例

static void Main(string[] args)
{
    Task t = new Task(() =>
    {
        Console.WriteLine("任务开始工作……");
        //模拟工作过程
        Thread.Sleep(5000);
    });
    t.Start();
    t.ContinueWith((task) =>
    {
        Console.WriteLine("任务完成，完成时候的状态为：");
        Console.WriteLine("IsCanceled={0}\tIsCompleted={1}\tIsFaulted={2}", 
                          task.IsCanceled, task.IsCompleted, task.IsFaulted);
    });
    Console.ReadKey();
}

无返回值使用方式总结

• Start方式启动

var t1 = new Task(() => TaskMethod("Task 1"));
t1.Start();
Task.WaitAll(t1);//等待所有任务结束 

• Run方式启动

Task.Run(() => TaskMethod("Task 2"));

• Factory方式启动

Task.Factory.StartNew(() => TaskMethod("Task 3")); //直接异步的方法 
//或者
var t3=Task.Factory.StartNew(() => TaskMethod("Task 3"));
Task.WaitAll(t3);//等待所有任务结束

• 综合示例

static void Main(string[] args)
{
    var t1 = new Task(() => TaskMethod("Task 1"));
    var t2 = new Task(() => TaskMethod("Task 2"));
    t2.Start();
    t1.Start();
    Task.WaitAll(t1, t2);
    Task.Run(() => TaskMethod("Task 3"));
    Task.Factory.StartNew(() => TaskMethod("Task 4"));
    //标记为长时间运行任务,则任务不会使用线程池,而在单独的线程中运行。
    Task.Factory.StartNew(() => TaskMethod("Task 5"), TaskCreationOptions.LongRunning);
    
    #region 常规的使用方式
    Console.WriteLine("主线程执行业务处理.");
    //创建任务
    Task task = new Task(() =>
                         {
                             Console.WriteLine("使用`System.Threading.Tasks.Task`执行异步操作.");
                             for (int i = 0; i < 10; i++)
                             {
                                 Console.WriteLine(i);
                             }
                         });
    //启动任务,并安排到当前任务队列线程中执行任务(System.Threading.Tasks.TaskScheduler)
    task.Start();
    Console.WriteLine("主线程执行其他处理");
    task.Wait();
    #endregion

    Thread.Sleep(TimeSpan.FromSeconds(1));
    Console.ReadLine();
}

static void TaskMethod(string name)
{
    Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
                      name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
}

• 使用async/await的实现方式

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

namespace ConsoleApp1
{
    class Program
    {
        async static void AsyncFunction()
        {
            await Task.Delay(1);
            Console.WriteLine("使用`System.Threading.Tasks.Task`执行异步操作.");
            for (int i = 0; i < 10; i++)
            {
                Console.WriteLine(string.Format("AsyncFunction:i={0}", i));
            }
        }

        public static void Main()
        {
            Console.WriteLine("主线程执行业务处理.");
            AsyncFunction();
            Console.WriteLine("主线程执行其他处理");
            for (int i = 0; i < 10; i++)
            {
                Console.WriteLine(string.Format("Main:i={0}", i));
            }
            Console.ReadLine();
        }
    }
}

有返回值使用方式

Task<int> task = CreateTask("Task 1");
task.Start(); 
int result = task.Result;

• 有返回值综合使用范例

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

namespace ConsoleApp1
{
    class Program
    {
        static Task<int> CreateTask(string name)
        {
            return new Task<int>(() => TaskMethod(name));
        }

        static void Main(string[] args)
        {
            TaskMethod("Main Thread Task");
            Task<int> task = CreateTask("Task 1");
            task.Start();
            int result = task.Result;
            Console.WriteLine("Task 1 Result is: {0}", result);

            task = CreateTask("Task 2"); 
            task.RunSynchronously(); //该任务会运行在主线程中
            result = task.Result;
            Console.WriteLine("Task 2 Result is: {0}", result);

            task = CreateTask("Task 3");
            Console.WriteLine(task.Status);
            task.Start();

            while (!task.IsCompleted)
            {
                Console.WriteLine(task.Status);
                Thread.Sleep(TimeSpan.FromSeconds(0.5));
            }

            Console.WriteLine(task.Status);
            result = task.Result;
            Console.WriteLine("Task 3 Result is: {0}", result);

            #region 常规使用方式
            //创建任务
            Task<int> getsumtask = new Task<int>(() => Getsum());
            //启动任务,并安排到当前任务队列线程中执行任务(System.Threading.Tasks.TaskScheduler)
            getsumtask.Start();
            Console.WriteLine("主线程执行其他处理");
            getsumtask.Wait(); //等待任务的完成执行过程
            Console.WriteLine("任务执行结果：{0}", getsumtask.Result.ToString());//获得任务的执行结果
            #endregion
        }

        static int TaskMethod(string name)
        {
            Console.WriteLine("Task {0} is running on a thread id {1}. Is thread pool thread: {2}",
                name, Thread.CurrentThread.ManagedThreadId, Thread.CurrentThread.IsThreadPoolThread);
            Thread.Sleep(TimeSpan.FromSeconds(2));
            return 42;
        }

        static int Getsum()
        {
            int sum = 0;
            Console.WriteLine("使用`Task`执行异步操作.");
            for (int i = 0; i < 100; i++)
            {
                sum += i;
            }
            return sum;
        }
    }
}

• 注意的是，使用返回值时通常是需要等待子线程执行结果的情况，会堵塞主线程

using System;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Program
    {
        public static void Main()
        {
            var ret1 = AsyncGetsum();
            Console.WriteLine("主线程执行其他处理");
            for (int i = 1; i <= 3; i++)
                Console.WriteLine("Call Main()");
            int result = ret1.Result;                  //阻塞主线程
            Console.WriteLine("任务执行结果：{0}", result);
        }

        async static Task<int> AsyncGetsum()
        {
            await Task.Delay(1);
            int sum = 0;
            Console.WriteLine("使用`Task`执行异步操作.");
            for (int i = 0; i < 100; i++)
            {
                sum += i;
            }
            return sum;
        }
    }
}

简单总结：有async Task修饰的方法，方法里面必然有await的调用或者有Task相关的效用。在外部可以直接调用async修饰的方法。在Addressables中大量使用了Task的异步操作，所以也可以使用await来让异步操作以等待的方式运行, await能让Addressables的使用更加方便，少了很多回调相关逻辑的编写。
可以参照：https://www.jianshu.com/p/dfa98f540673

参考：
https://www.cnblogs.com/zhaoshujie/p/11082753.html
https://blog.csdn.net/kingBook928/article/details/104958881?spm=1001.2101.3001.6650.1&utm_medium=distribute.pc_relevant.none-task-blog-2%7Edefault%7ECTRLIST%7ERate-1.pc_relevant_default&depth_1-utm_source=distribute.pc_relevant.none-task-blog-2%7Edefault%7ECTRLIST%7ERate-1.pc_relevant_default&utm_relevant_index=2