The windows guidlines state ...
Rather than flashing the button continually, you can flash the window button
only a limited number of times (for example, three), then leave the button
in the highlighted state, as shown in Figure 11.2. This lets users know
there is still a pending message.
From what i have been able to gather, flashing itself is very easy (Just call the Flash method on the windows form.)
To leave the button in the highlighted state, I resorted resorted to using the user32.dll method call FlashWindow() ... this was the code added ...
using System.Runtime.InteropServices;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
public static extern int FlashWindow(IntPtr hWnd, bool state);
These are the existing Flash methods in the windows form ...
public void Flash();
public void Flash(int flashRate, FlashWindow flashWhat, bool continuousUntilActivated);
I propose a third
public void Flash(int flashRate, FlashWindow flashWhat, bool continuousUntilActivated, bool leaveHighlighted);
Note the last bool ...

Flashing in the TaskBar
KarthikChennappan
public void Flash(int flashRate, int flashTimes, FlashWindow flashWhat, bool continuousUntilActivated, bool leaveHighlighted);
vizca