Access Progress Bar On Main Form From Thread On User Control?
Aug 18, 2009
I have a windows application with a main form, on which a user control is added dynamically when a device connects trough USB.
On a user control, there is a thread wich is getting data from the device trough USB and when it is finished, I want to change a progressbar that is located on the main windows form where user control reside.
This is the code that is I call on the user control thread to change the progress bar value:
Frm_Main.UpdateProgressBar(CInt((AllBytesReceived / MaxBytesInFlash) * 100))
and this is a code that is called on the main form:
Private Delegate Sub UpdateProgressBarDelegate(ByVal value As Integer)
Preface: I know this is an unusual/improper way to do this. I can do this with a "real" ShowDialog(), background worker/thread, and so on. I am trying to do specifically what I describe here, even if it is ugly. If this is impossible for X reason, I have created a fancy progress dialog for some of our long running operations. I need to have this dialog shown on a new thread while having processing continue on the calling (UI in most cases) thread.
Would anyone be able to help me here please. I'm fairly new to VB.net and threading so im just trying to figure out what is happening.When I debug this I am getting the error thread operation not valid: Control 'ProgressBar1' accessed from a thread other than the thread it was created on.
I'm a little lost as to why the error is occuring or how to fix it. I've had to put the progress bar in a separate thread otherwise the GUI crashes
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i want to start a Sub (DoWork) in the module but in a new thread.
Dim Thread1 As System.Threading.Thread Thread1 = New Threading.Thread(AddressOf mod1.DoWork) Thread1.Start()
The DoWork sub does some stuff and when it's finished i want to change the text of a textbox1 in the main form and start another sub (DoWork2) on the main form under the main thread not the one DoWork is running under.
Plese do not refer me to another post that mighe give me a part answer, try to explain to me what i have to do and why.
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[code]....
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[code]....
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