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cancel backgroundworker from a separate form
Hi Experts,
i'm very new at VB and here is my dilema, i have form A that calls a backgroundwoeker to run a very long process. once the user clicks on submit on form A it calls the BGworker and opens form B.
on form B load i'm closing form A - form B has a progress bar, a cancel button and other info i display to the user what i'm stuck is with the cancel button - how can i have form B send a cancelationrequest to the backgroundworker.
Also if not too much to ask - how can i catch progresschangeevents and workercompleted events in form B
Many thanks in advance.
i'm very new at VB and here is my dilema, i have form A that calls a backgroundwoeker to run a very long process. once the user clicks on submit on form A it calls the BGworker and opens form B.
on form B load i'm closing form A - form B has a progress bar, a cancel button and other info i display to the user what i'm stuck is with the cancel button - how can i have form B send a cancelationrequest to the backgroundworker.
Also if not too much to ask - how can i catch progresschangeevents and workercompleted events in form B
Many thanks in advance.
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Where is the backgroundworker? Is it on FormA or on a separate class? You can pass the reference of backgroundworker from FormA to FormB(using a class level variable in FormB) and then use it to cancel. To catch the events, you would need to use AddHandler statement.
Why not add the backgroundworker on FormB?
Why not add the backgroundworker on FormB?
Hi CodeCruiser,
The BGworker is on a dll i created with the entire long process - i'm passing some data from FORM A to it - that's why im calling it from there - FORM B has the progress bar and other indicators i want the user to see while the BGWorker is doing it's thing.
Thanks,
The BGworker is on a dll i created with the entire long process - i'm passing some data from FORM A to it - that's why im calling it from there - FORM B has the progress bar and other indicators i want the user to see while the BGWorker is doing it's thing.
Thanks,
Two options then
1) Eliminate formB and show progress etc on FormA
2) Use FormA to pass the reference of BGW to FormB like below
FormB:
Public BGW As BackGroundWorker
BGW_ProgressChanged
BGW_WorkerCompleted
FormA:
Dim frm As New FormB
frm.BGW = dll.BGW
AddHandler dll.BGW.ProgressChanged, AddressOf frm.ProgressChanged
AddHandler dll.BGW_WorkerCompleted, AddressOf frm.WorkerCompleted
1) Eliminate formB and show progress etc on FormA
2) Use FormA to pass the reference of BGW to FormB like below
FormB:
Public BGW As BackGroundWorker
BGW_ProgressChanged
BGW_WorkerCompleted
FormA:
Dim frm As New FormB
frm.BGW = dll.BGW
AddHandler dll.BGW.ProgressChanged, AddressOf frm.ProgressChanged
AddHandler dll.BGW_WorkerCompleted, AddressOf frm.WorkerCompleted
Send the object of BackGroundWorker Class as a parameter to a parameterized constructor of Form B. Then in a button click from Form B. Call the CancelAsync() Method of BackGroundWorker object. Like so Suppose name of the object is bgWorker :
bgWorker.CancelAsync();
Constructor of Form B will be as follows :
Dim BackGroundWorker bgWorker
Public FormB(BackGroundWorker worker)
Begin
Me.bgWorker = worker
End
Sorry guys,
i have been trying to get this to work for the past hour with no luck. and I made a mist when i was writing my explanation above. the backgroundwork is being called from FORM A - and sending all the process contained in the dll to it. I'm not sure if this changes things.
@codecruiser - I guess i could do option 1 if everything else fails
@ starlite551 - I did not understood how to implement the constructor on form b - i have attached my current code on FORM B
Thanks you both
i have been trying to get this to work for the past hour with no luck. and I made a mist when i was writing my explanation above. the backgroundwork is being called from FORM A - and sending all the process contained in the dll to it. I'm not sure if this changes things.
@codecruiser - I guess i could do option 1 if everything else fails
@ starlite551 - I did not understood how to implement the constructor on form b - i have attached my current code on FORM B
Thanks you both
Imports System.ComponentModel
Public Class FProcessing
Private Sub FProcessing_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
FParse.Close()
Timer1.Interval = 1000
Timer1.Start()
End Sub
Private Sub Timer1_Timer(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
Label6.Text = myDLL.PUBLICVARIABLES.VAR1 Label3.Visible = Not Label3.Visible
ProgressBar1.Maximum = 100 + myDLL.PUBLICVARIABLES.tot
ProgressBar1.Value = 1 + myDLL.PUBLICVARIABLES.cpa
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'If bg.WorkerSupportsCancellation = True Then
'bw.CancelAsync()
'End If
End Sub
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