在后台播放提示音

Question

With some references from other websites, I have developed a code which checks whether an Item is available for sale or not.
If the Item is unavailable, It should make a beep sound in background along with a dialog box (Retry/Cancel).

Further, if user clicks on Retry, The beep sound Should not stop.
Else clicking on Cancel should stop the beep sound in background.

The code i used

                    if()
                    {
                     Item exists code
                    }
                    else
                    {
                        //Item Not found
                        retry();
                    }

public void retry()
    {
        Thread beepThread = new Thread(new ThreadStart(PlayBeep));
        beepThread.IsBackground = true;

        if (MessageBox.Show("Item not found", "Alert", MessageBoxButtons.RetryCancel) == DialogResult.Retry)
        {                
            beepThread.Start();                
            retry();
        }
        else
        {
            beepThread.Abort();
            Console.Beep(500, 1);
            return;
        }
    }

    private void PlayBeep()
    {
        Console.Beep(500, int.MaxValue);
    }

Using the above code, plays the sound when I click on retry but I want it to play as soon as It enters Else condition (When Item is not found)
Any suggestions?

Answer 1

You should start the beep sound right before the messagebox appears. In order not to have too many unused threads you have to abort them in both cases.
Finally I would suggest using a while(true) loop in order to get an endless beep sound.

    public void retry()
    {
        Thread beepThread = new Thread(new ThreadStart(PlayBeep));
        beepThread.IsBackground = true;
        beepThread.Start();

        if (MessageBox.Show("Item not found", "Alert", MessageBoxButtons.RetryCancel) == DialogResult.Retry)
        {
            beepThread.Abort();
            retry();
        }
        else
        {
            beepThread.Abort();
            Console.Beep(500, 1);
            return;
        }
    }

    private void PlayBeep()
    {
        while(true)
           { Console.Beep(500, int.MaxValue); }
    }