Cannot await 'void'

Question

this is my script.

        private async void secondmult_Click(object sender, EventArgs e)
        {
            var sct = sc;
            var secondmultx = secondmult;

            if (player.pcc == 100)
            {
                player.multiplier = 2;
                player.pcc = player.pcc - 100;
                secondmult.Enabled = false;
                sct.Text = player.pcc.ToString();
            }
            else if(player.pcc < 100)
            {
                sc.Text = "X";
                await Thread.Sleep(3000);
                sc.Text = player.pcc.ToString();
            }
            else if(player.pcc > 100)
            {
                player.multiplier = 2;
                player.pcc = player.pcc - 100;
                secondmultx.Enabled = false;
                sct.Text = player.pcc.ToString();
            }

There is an error on the line 'await Thread.Sleep(3000);' It says 'Cannot await 'void'' Please may someone re-do the script for me so it works?

If you declare that the method is async it should have a return type of Task, else it will not have the behaviour that you expect. — Omar Abdel Bari, Nov 01 '20 at 06:18
@OmarAbdelBari this is a top-level event handler - it can't be a `Task` - it has to be an `async void`. See https://stackoverflow.com/questions/19415646/should-i-avoid-async-void-event-handlers — CoolBots, Nov 01 '20 at 06:23
@Bishan does not apply - the OP has the correct method signature, but calling a *non-awaitable expression* with an `await` keyword. — CoolBots, Nov 01 '20 at 06:28
I know I mistook the error with a compiler warning that I remember seeing — Omar Abdel Bari, Nov 01 '20 at 06:32

score 3 · Answer 1 · answered Nov 01 '20 at 06:19

3

Thread.Sleep() is not awaitable. Use Task.Delay() instead.

answered Nov 01 '20 at 06:19

CoolBots

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score 1 · Accepted Answer · edited Nov 01 '20 at 06:55

1

Thread.sleep(3000) is not awaitable. Your method is async so ideal implementation will be await Task.Delay(3000)

Thread.Sleep is going to block your current thread and Task.Delay is going to delay logically without blocking your current thread.

Thread.sleep should not be used in asynchronous operation instead we should use Task.Delay(3000) and vice versa.

edited Nov 01 '20 at 06:55

Dharman

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answered Nov 01 '20 at 06:49

sobby01

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Cannot await 'void'

2 Answers2