C# subscribe a function to System.Action that is subscribed to another System.Action: why does order matter?

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C# subscribe a function to System.Action that is subscribed to another System.Action: why does order matter?
ReSharper always asks to change System.Action to System.Action<T>
Argument 'System.Action' is not assignable to parameter type 'System.Threading.SendOrPostCallback'
Cannot convert type 'System.Action<int>' to 'System.Action<object>'
Cannot convert from 'void' to System.Threading.Tasks.Task<System.Action>
Who should subscribe to NGXS async action - the dispatch action caller or the @Action handler?

C# subscribe a function to System.Action that is subscribed to another System.Action: why does order matter?

Tag : chash , By : user109285

Date : November 28 2020, 09:01 AM

will help you This is relatively apparent from examining how delegates work and the MSIL that is created when you compile this. First lets note that System.Action is a System.Delegate which has the ICloneable interface.
When you compile this program, here is pretty much what you get:

  IL_0015:  newobj     instance void [mscorlib]System.Action::.ctor(object,
                                                                    native int)
  IL_001a:  call       class [mscorlib]System.Delegate [mscorlib]System.Delegate::Combine(class [mscorlib]System.Delegate,
                                                                                          class [mscorlib]System.Delegate)
  IL_001f:  castclass  [mscorlib]System.Action
  IL_0024:  stfld      class [mscorlib]System.Action ConsoleTests.Program6/Chunk::OnTrigger
  IL_0029:  ldloc.0
  IL_002a:  ldfld      class ConsoleTests.Program6/Leaf ConsoleTests.Program6/Chunk::leaf
  IL_002f:  dup
  IL_0030:  ldfld      class [mscorlib]System.Action ConsoleTests.Program6/Leaf::OnTrigger
  IL_0035:  ldloc.0
  IL_0036:  ldfld      class [mscorlib]System.Action ConsoleTests.Program6/Chunk::OnTrigger
  IL_003b:  call       class [mscorlib]System.Delegate [mscorlib]System.Delegate::Combine(class [mscorlib]System.Delegate,
                                                                                          class [mscorlib]System.Delegate)
  IL_0040:  castclass  [mscorlib]System.Action
  IL_0045:  stfld      class [mscorlib]System.Action ConsoleTests.Program6/Leaf::OnTrigger
  IL_004a:  ldloc.0
  IL_004b:  dup
  IL_004c:  ldfld      class [mscorlib]System.Action ConsoleTests.Program6/Chunk::OnTrigger
  IL_0051:  ldnull
  IL_0052:  ldftn      void ConsoleTests.Program6::World()
  IL_0058:  newobj     instance void [mscorlib]System.Action::.ctor(object,
                                                                    native int)
  IL_005d:  call       class [mscorlib]System.Delegate [mscorlib]System.Delegate::Combine(class [mscorlib]System.Delegate,
                                                                                          class [mscorlib]System.Delegate)
  IL_0062:  castclass  [mscorlib]System.Action
  IL_0067:  stfld      class [mscorlib]System.Action ConsoleTests.Program6/Chunk::OnTrigger
  IL_006c:  ldloc.0
  IL_006d:  ldfld      class ConsoleTests.Program6/Leaf ConsoleTests.Program6/Chunk::leaf
  IL_0072:  callvirt   instance void ConsoleTests.Program6/Leaf::Go()

public Tree()
{
    var chunk2 = new Chunk();
    chunk2.OnTrigger += Hello; // OK: will be called
    chunk2.leaf.OnTrigger = (Action)chunk2.OnTrigger.Clone();
    chunk2.OnTrigger += World; // NOT: not be called
    chunk2.leaf.Go();
}

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C# subscribe a function to System.Action that is subscribed to another System.Action: why does order matter , ReSharper always asks to change System.Action to System.Action<T> , Cannot convert type System.Action<int> to System.Action<object> , Who should subscribe to NGXS async action - ,

ReSharper always asks to change System.Action to System.Action<T>

Tag : chash , By : CookingCoder

Date : March 29 2020, 07:55 AM

this will help Seems to me that you need to update ReSharper to the latest version, which is version 5.1. If you have items that are not loaded by ReSharper (i.e., check your excluded items list), then it will mark them as unknown, even if your code is legal and references the items.
You may try Clear Cache, or reset default settings.

private Action ExtractFile()
{
    return () => MessageBox.Show("Test");
}

Argument 'System.Action' is not assignable to parameter type 'System.Threading.SendOrPostCallback'

Tag : chash , By : flesk

Date : March 29 2020, 07:55 AM

fixed the issue. Will look into that further From MSDN.

public virtual void Send(SendOrPostCallback d, Object state)

public delegate void SendOrPostCallback(Object state)

syncContext.Send(new Action(o => { ...

Cannot convert type 'System.Action<int>' to 'System.Action<object>'

Tag : chash , By : liquidx

Date : March 29 2020, 07:55 AM

like below fixes the issue I am wondering how I achieve something like this? , Well, you could wrap the first action:

Action<object> test2 = (object o) => test((int)o);

Cannot convert from 'void' to System.Threading.Tasks.Task<System.Action>

Tag : chash , By : UnKnownUser

Date : March 29 2020, 07:55 AM

like below fixes the issue I have write generic method using hangfire .Net. Basically i want to achieve that i have generate one method and want to call it multiple times when ever it is required. My helper method is below: , I have done it by changing my methods like

 public static void ScheduleBackGroundJob(Expression<Action> _refmethod, DateTime _dateTime)
    {
        try
        {
            var _currentDate = DateTime.Now;
            TimeSpan _timeSpan = _dateTime - _currentDate;
            BackgroundJob.Schedule(_refmethod, _timeSpan);
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

 HangfireHelper.ScheduleBackGroundJob(() => _service.UpdateAuctionStatus(result), result.PlannedCloseDate);

  public async Task UpdateAuctionStatus(AuctionReturnModel model)
    {
        try
        {
            var _auction = await (from d in _db.Auction_Detail where d.Id == model.AuctionDetailId select d).FirstOrDefaultAsync();
            _auction.isEnded = true;
            _db.Auction_Detail.Add(_auction);
            _db.SaveChanges();

            var _auctionHistory = new AuctionHistory { AuctionDetail_Id = model.AuctionDetailId, EndedDate = DateTime.Now, EndedMethod = "Automatic" };
            _db.AuctionHistory.Add(_auctionHistory);
            _db.SaveChanges();

            Task.WaitAll();

        }
        catch (Exception ex)
        {
            throw ex;
        }
    }

Who should subscribe to NGXS async action - the dispatch action caller or the @Action handler?

Tag : development , By : sam

Date : March 29 2020, 07:55 AM

this one helps. I think it is somewhat a matter of style, but I'd say (from my usage of NGXS) this is most typical:
On dispatch do this, and only subscribe here if there's some post-action you want to do.