c# 在Emit代码中如何await一个异步方法

  public static async Task<int> GetV()
  {
   await Task.Delay(2000);
   return 55;
  }

  private static async Task Test(MethodInfo method, MethodInfo awaitMehtod)
  {
   var caller = CreateCaller(method, awaitMehtod);
   Console.WriteLine($"Start {awaitMehtod.Name} at: {DateTime.Now}.");
   var task = caller();
   Console.WriteLine($"Call done at: {DateTime.Now}.");
   var number = await task;
   Console.WriteLine($"Hello {number} at: {DateTime.Now}.");
   Console.WriteLine($"End at: {DateTime.Now}.");
   Console.WriteLine();
  }

  public static Func<Task<int>> CreateCaller(MethodInfo method, MethodInfo awaitMehtod)
  {
   var m = new DynamicMethod(Guid.NewGuid().ToString("N"), typeof(Task<int>), Type.EmptyTypes);
   var il = m.GetILGenerator();
   il.Emit(OpCodes.Call, method);
   il.Emit(OpCodes.Call, typeof(Program).GetMethod(nameof(Program.AddSixUseContinueWith))); // 这里是差异点
   il.Emit(OpCodes.Ret);

   return m.CreateDelegate(typeof(Func<Task<int>>)) as Func<Task<int>>;
  }

  public static Task<int> AddSixUseContinueWith(Task<int> task)
  {
   return task.ContinueWith(i =>
   {
    Console.WriteLine($"AddSixUseContinueWith is: {DateTime.Now}.");
    return i.Result + 6;
   });
  }

Start AddSixUseContinueWith at: 2021/1/2 13:34:55.
Call done at: 2021/1/2 13:34:55.
AddSixUseContinueWith is: 2021/1/2 13:34:57.
Hello 61 at: 2021/1/2 13:34:57.
End at: 2021/1/2 13:34:57.

  public static Func<Task<int>> CreateCaller(MethodInfo method, MethodInfo awaitMehtod)
  {
   var m = new DynamicMethod(Guid.NewGuid().ToString("N"), typeof(Task<int>), Type.EmptyTypes);
   var il = m.GetILGenerator();
   il.Emit(OpCodes.Call, method);
   il.Emit(OpCodes.Call, typeof(Program).GetMethod(nameof(Program.AddSixUseAwaiter))); // 这里是差异点
   il.Emit(OpCodes.Ret);

   return m.CreateDelegate(typeof(Func<Task<int>>)) as Func<Task<int>>;
  }

  public static Task<int> AddSixUseAwaiter(Task<int> task)
  {
   var r = task.ConfigureAwait(false).GetAwaiter().GetResult() + 6;
   Console.WriteLine($"AddSixUseAwaiter is: {DateTime.Now}.");
   return Task.FromResult(r);
  }

Start AddSixUseAwaiter at: 2021/1/2 13:34:57.
AddSixUseAwaiter is: 2021/1/2 13:34:59.
Call done at: 2021/1/2 13:34:59.
Hello 61 at: 2021/1/2 13:34:59.
End at: 2021/1/2 13:34:59.

  public static Func<Task<int>> CreateCaller(MethodInfo method, MethodInfo awaitMehtod)
  {
   var m = new DynamicMethod(Guid.NewGuid().ToString("N"), typeof(Task<int>), Type.EmptyTypes);
   var il = m.GetILGenerator();
   il.Emit(OpCodes.Call, method);
   il.Emit(OpCodes.Call, typeof(Program).GetMethod(nameof(Program.AddSixUseAsyncAwait))); // 这里是差异点
   il.Emit(OpCodes.Ret);

   return m.CreateDelegate(typeof(Func<Task<int>>)) as Func<Task<int>>;
  }

  public static async Task<int> AddSixUseAsyncAwait(Task<int> task)
  {
   var r = await task;
   Console.WriteLine($"AddSixUseAsyncAwait is: {DateTime.Now}.");
   return r + 6;
  }

Start AddSixUseAsyncAwait at: 2021/1/2 13:34:59.
Call done at: 2021/1/2 13:34:59.
AddSixUseAsyncAwait is: 2021/1/2 13:35:01.
Hello 61 at: 2021/1/2 13:35:01.
End at: 2021/1/2 13:35:01.