Why Invoke a delegate rather than simply calling the method?

[adamhb]

Hi

I am looking at the NetworkVariable example that ships with MS 8.1 Professional, "Basic.2005".

In the BufferedWriter.2005 project, to plot values to the WaveformGraph the following code is used:
Invoke(new EventHandler(delegate{ sampleWaveformGraph.PlotYAppend(values); }));

Why don't you simply call the method on the instance of the WaveformGraph?:
sampleWaveformGraph.PlotYAppend(values);

Thanks

Adam

[bilalD]

The WriteData method is executing in a worker (non-UI) thread. Windows programming prohibits updating UI controls from a thread other than the one that created the UI in the first place. By using Invoke, we make sure that the PlotYAppend method executes in the thread that owns the sampleWaveformGraph. See the help for Invoke for more information. Not doing this would cause the application to throw weird errors, even though it may seem things are working in the beginning.


Hope this helps.