How can I wait for asynchronous surgery?

Question

All good times of day! Who knows how to wait for asynchronous surgery? I use a crutch in the form of a bool variable and a cycle while with Task.Delay. Thank you in advance.
P. S. I used a translator
https://code.sololearn.com/ciu0K2815HKa/?ref=app

Answer 1

Place a listbox on the form.
Add all messages to the listbox like

ShowMessage("Download completed"); becomes Listbox1.Add("Download completed");

Doing it this way, you can follow every event that is being fired. Without clicking to many messageboxes.

Make list of files you want to download

Take the first file of the list in the buttonclick.
Make a method "download" file.
Start next download in download completed

Answer 2

Why do you want to do that ?
You code seems to be ok.
Asynchronous means you do not have to wait.
If you need to do something after the file is downloaded do it in "download complete" event.