Determines whether the specified key is up or downby calling the NativeMethods.GetKeyState function. (See: http://msdn.microsoft.com/en-us/library/ms646301(VS.85).aspx)
The key status returned from this function changes as a thread reads key messages from its message queue. The status does not reflect the interrupt-level state associated with the hardware. Use the GetAsyncKeyState function to retrieve that information. An application calls GetKeyState in response to a keyboard-input message. This function retrieves the state of the key when the input message was generated. To retrieve state information for all the virtual keys, use the GetKeyboardState function. An application can use the virtual-key code constants VK_SHIFT, VK_CONTROL, and VK_MENU as values for Bthe nVirtKey parameter. This gives the status of the SHIFT, CTRL, or ALT keys without distinguishing between left and right. An application can also use the following virtual-key code constants as values for nVirtKey to distinguish between the left and right instances of those keys. VK_LSHIFT VK_RSHIFT VK_LCONTROL VK_RCONTROL VK_LMENU VK_RMENU These left- and right-distinguishing constants are available to an application only through the GetKeyboardState, SetKeyboardState, GetAsyncKeyState, GetKeyState, and MapVirtualKey functions.
