Callbacks problems

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Hey guys,

I've got a multithreaded application. The GUI runs on its own thread whilst a background worker thread will get invovked later on. Now the problem occurs when the bakground thread trys to manipulate the GUI thread.

Solution is a callback using invokeRequired.

C# Syntax (Toggle Plain Text)
public void ThreadProcSafe2(String text)
        {
            if (this.m_AllKnownDevicesFrm.InvokeRequired)
            {
                // It's on a different thread, so use Invoke.
                SetTextCallback3 d = new SetTextCallback3(switchPanels);
                this.Invoke(d, new object[] {1} );
 
            }
            else
            {
                switchPanels(1);
            }
        }
public void ThreadProcSafe2(String text)
        {
            if (this.m_AllKnownDevicesFrm.InvokeRequired)
            {
                // It's on a different thread, so use Invoke.
                SetTextCallback3 d = new SetTextCallback3(switchPanels);
                this.Invoke(d, new object[] {1} );
                
            }
            else
            {
                switchPanels(1);
            }
        }

But this fails when its running... With error of

Quote ...

"invalid parameter"

switchPanels is a method declared to take an int has an agrument.

Confused. Can anyone shread any light onto this problem?

Thanks guys...

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Acidburn

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since Dec 2004

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Apr 8th, 2009

Re: Callbacks problems

try this

its unclear why you are using string text as a parameter if its not being passed on, but here it is

C# Syntax (Toggle Plain Text)
void delegate textCallback(string text);
public void ThreadProcSafe2(String text)
        {
            if (this.m_AllKnownDevicesFrm.InvokeRequired)
            {
                this.m_AllKnownDevicesFrm.Invoke(new textCallback(ThreadProcSafe2), text);                
            }
            else
            {
                switchPanels(1);
            }
        }
void delegate textCallback(string text);
public void ThreadProcSafe2(String text)
        {
            if (this.m_AllKnownDevicesFrm.InvokeRequired)
            {
                this.m_AllKnownDevicesFrm.Invoke(new textCallback(ThreadProcSafe2), text);                
            }
            else
            {
                switchPanels(1);
            }
        }

dickersonka

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