Don’t use async void
An async method may return Task, Task<T> and void. Natural return types are all but void.
Any sync method returning void becomes an async method returning Task.
example:
// synchronous work
void MyMethod()
{
Thread.sleep(1000);
}
// asynchronous work
async Task MyAsyncMethod()
{
await Task.Delay(1000);
}
When an exception is thrown out of an async Task or async Task<T> method that exception is captured and placed on the Task object. For async void methods, exceptions aren’t caught.
example:
private async void ThrowExceptionAsync()
{
throw new InvalidOperationException();
}
public void AsyncVoidExceptions_CannotBeCaught()
{
try
{
ThrowExceptionAsync();
}
catch(Exception)
{
// The exception is never caught here!
throw;
}
}
The exception to use async void are asynchronous event handlers.
example:
private async void button1_clicl(object sender, EventArgs e)
{
await Button1ClickAsync(); // my method
}