C#•2y ago

❔ await nullable return values

I have a function returning a nullable class. The compiler complains at the await line it cannot implicity perform the conversion even though they are both the same type.

10 Replies

Angius•2y ago

So you return a Task<T>? ? Why? Why not Task<T?>?

r2d25551OP•2y ago

public class MyEventArgs : EventArgs
{
    public string data { get; set; } = string.Empty;
}


protected async Task<MyEventArgs?> MyTask()
{
   bool done = true;

   if (done)
   {
      return (MyEventArgs?)null;
   }

   return new MyEventArgs{ data = "" };
}

protected aysnc MoreToProcess()
{
    Task<MyEventArgs?> args = await MyTask();
}

public class MyEventArgs : EventArgs
{
    public string data { get; set; } = string.Empty;
}


protected async Task<MyEventArgs?> MyTask()
{
   bool done = true;

   if (done)
   {
      return (MyEventArgs?)null;
   }

   return new MyEventArgs{ data = "" };
}

protected aysnc MoreToProcess()
{
    Task<MyEventArgs?> args = await MyTask();
}

Angius•2y ago

uh awaiting strips the Task away

r2d25551OP•2y ago

The return type is derived from EventArgs

Angius•2y ago

args will be of type MyEventArgs? Not Task<MyEventArgs?>

r2d25551OP•2y ago

Trying now. . .

Ꜳåąɐȁặⱥᴀᴬ•2y ago

or use var

Angius•2y ago

That's the easy way out, yeah lol

r2d25551OP•2y ago

Thank you 😄 😄 😄 that worked. I need to not that await strips the task out.

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ await nullable return values

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