Communications :: Involving Cross Threads In .NET 2005?

Feb 8, 2010

My application need to communicate with my self made device through serial port. I have to change the selected index of Tabs when I press a button on my device. I have Form1, Form2, Module1 Form1 Contains the Serial Port Control. Form2 contains the Tab which needs to be changed. When I press a button on device them, the button pressed is stored in an integer form in a global variable.The Interrupt for the Serial Port directs the control to the module1 where I decide using Select Case that what index of which TabControl I have to select.Depending on that, I change the Index of the required Tab.

PROBLEM:cross thread exception is fired as soon as the control reaches the statement where I Modify the SelectIndex property from the select case at Module1.While, on my other PC, the SelectIndex property is changed, but the next tab is not shown.

BUT, if I put all this code in a button control, and try to activate from there, then it works perfectly. However, I have to navigate through the tab controls using my self made device.I searched a lot on net and came across a solution which describes that we have to use delegate function and invokeRequired methods to ensure that the procedures run on the same thread.I am not able to decide that where exactly shoud the code for delegates and all be written, in form1, or form2, or module1.Also, in the hit and try that I did, I always got the value of InvoleRequired as False.

Here is the part of Code that I wrote for Delegates

Code:

'Form 1 is BLINDHELPER_SIGNIN
'form 2 is BLINDHELPER_USER

' I have defined these at Module1

Public Delegate Sub DeleToManageTabs(ByVal tb As TabControl)
Public Sub manage_Tabs(ByVal tab As TabControl)
MsgBox(tab.Name)

[code]....

After using this code also, there is no change in working of my application.

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