How to properly exit from canceled BackgroundWorker async? - vb.net

Question

I'm currently using this code, (which is working) but I'm not satisfied with how it looks... Is there a more professional way to do it ?
Here's the code I use now :
Private Sub BackgroundWorker_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker.DoWork
Try
If BackgroundWorker.CancellationPending Then
e.Cancel = True
Exit Sub
End If
LatestVersion = Web.DownloadString(UpdateLink)
If BackgroundWorker.CancellationPending Then
e.Cancel = True
Exit Sub
End If
If LatestVersion.Contains(InstalledVersion) Then
e.Result = UP_TO_DATE
Else
e.Result = OUTDATED
End If
Web.Dispose()
Catch ex As Exception
e.Result = ex.Message
End Try
End Sub
As you can see, I'm repeating two times the same condition. But imagine if there was more code, I should have repeat it more times...
My problem is that I would like to exit the Sub at anytime, as long as the BackgroundWorker.CancellationPending property is set to True.
I'm using the same condition two times because I wanna check if the operation has been canceled before, and after downloading of my string (I don't wanna wait for the string to be downloaded whereas I've already canceled the operation... it's a waste of time).
Should I use a While statement ? If yes, how ?

Answer 1

Don't use BackgroundWorker and this problem goes away. The code probably should be (mixture of VB and C#):
//Instance field:
CancellationTokenSource cts = ...;
//Update method
var downloadTask = HttpClient().DownloadString(UpdateLink, cts.Token);
await Task.WhenAll(downloadTask, cts.Token); //Wait with timeout
LatestVersion = await downloadTask;
If LatestVersion.Contains(InstalledVersion) Then
ShowResult(UP_TO_DATE);
Else
ShowResult(OUTDATED);
End If
And if you want to cancel, signal cts.
Also, error handling is missing. This is easy to test for and add.

Answer 2

I've found another solution. By the way, I've renamed Web by WebClient...
Here's my code :
Private Sub Form1_Load() Handles Form1.Load
AddHandler WebClient.DownloadStringCompleted, AddressOf WebClient_DownloadStringCompleted
End Sub
Private Sub BackgroundWorker_DoWork() Handles BackgroundWorker.DoWork
WebClient.DownloadStringAsync(New Uri(UpdateLink))
End Sub
Private Sub WebClient_DownloadStringCompleted(sender As Object, e As System.Net.DownloadStringCompletedEventArgs)
Dim Output As String = Nothing
If Not e.Cancelled Then
LatestVersion = e.Result
If LatestVersion.Contains(InstalledVersion) Then
Output = UP_TO_DATE
Else
Output = OUTDATED
End If
End If
End Sub
And, to cancel the operation, I run WebClient.CancelAsync().