///--------------------------------------------------------------------
/// <summary>
/// Obtains a WindowPattern control pattern from an automation element.
/// </summary>
/// <param name="targetControl">
/// The automation element of interest.
/// </param>
/// <returns>
/// A WindowPattern object.
/// </returns>
///--------------------------------------------------------------------
private WindowPattern GetWindowPattern(AutomationElement targetControl)
{
    WindowPattern windowPattern = null;

    try
    {
        windowPattern =
            targetControl.GetCurrentPattern(WindowPattern.Pattern)
            as WindowPattern;
    }
    catch (InvalidOperationException)
    {
        // object doesn't support the WindowPattern control pattern
        return null;
    }
    // Make sure the element is usable.
    if (false == windowPattern.WaitForInputIdle(10000))
    {
        // Object not responding in a timely manner
        return null;
    }
    return windowPattern;
}

///--------------------------------------------------------------------
/// <summary>
/// Calls the WindowPattern.SetVisualState() method for an associated 
/// automation element.
/// </summary>
/// <param name="windowPattern">
/// The WindowPattern control pattern obtained from
/// an automation element.
/// </param>
/// <param name="visualState">
/// The specified WindowVisualState enumeration value.
/// </param>
///--------------------------------------------------------------------
private void SetVisualState(WindowPattern windowPattern, 
    WindowVisualState visualState)
{
    try
    {
        if (windowPattern.Current.WindowInteractionState ==
            WindowInteractionState.ReadyForUserInteraction)
        {
            switch (visualState)
            {
                case WindowVisualState.Maximized:
                    // Confirm that the element can be maximized
                    if ((windowPattern.Current.CanMaximize) && 
                        !(windowPattern.Current.IsModal))
                    {
                        windowPattern.SetWindowVisualState(
                            WindowVisualState.Maximized);
                        // TODO: additional processing
                    }
                    break;
                case WindowVisualState.Minimized:
                    // Confirm that the element can be minimized
                    if ((windowPattern.Current.CanMinimize) &&
                        !(windowPattern.Current.IsModal))
                    {
                        windowPattern.SetWindowVisualState(
                            WindowVisualState.Minimized);
                        // TODO: additional processing
                    }
                    break;
                case WindowVisualState.Normal:
                    windowPattern.SetWindowVisualState(
                        WindowVisualState.Normal);
                    break;
                default:
                    windowPattern.SetWindowVisualState(
                        WindowVisualState.Normal);
                    // TODO: additional processing
                    break;
            }
        }
    }
    catch (InvalidOperationException)
    {
        // object is not able to perform the requested action
        return;
    }
}