Open WPF window near to notification area with support multiply monitors

Question

My wpf application should open a window nearing to notification area. When the user clicks on the tray icon opens a window. So i need the window on the same screen where the notification area. For now i just getting taskbar location: https://stackoverflow.com/a/8581546/1502011 and taskbar rectlange on the screen https://stackoverflow.com/a/3677319/1502011 and then i use it for locate my window like:

//xaml.cs
var taskBarLocation = GetTaskBarLocation();
var taskBarPosition = GetTaskbarPosition();

this.Left = taskBarLocation == Location.Left
            ? taskBarPosition.Width
            : SystemParameters.WorkArea.Width - Width;

this.Top = taskBarLocation == Location.Top
            ? taskBarPosition.Height
            : SystemParameters.WorkArea.Height - Height;

It works only if the notification area are placed at the primary screen. As i understood i should use WinApi for place my window on other monitor but i even don't know how to find screen with the notification area. Any help will be appreciated.

Have you tried browsing through the `System.Windows.Forms.Screen.AllScreens` property? it's an array of type `Screen`. You can check if the screen is the primary screen. And isn't the notification area connected to the taskbar? — Mike, Jan 07 '15 at 10:02
Thanks for your responds! I didn't know the wpf window coords points to display coords and i can simply move the window by set it coordinates out of primary screen. I also didn't know that SHAppBarMessage returns display coords. — tnimas, Jan 21 '15 at 12:20

score 1 · Accepted Answer · answered Jan 21 '15 at 12:09

Ok, since

1) Wpf window location don't care about monitors ( it's work on "Control Panel\All Control Panel Items\Display\Screen Resolution" coordinates, not on current screen coordinates )

2) WinApi method SHAppBarMessage(5, ref data) also works in global coordinates

3) Each screen object have Bounds property that represents place of the screen at global coordinates

The solution is quite simple:

public static class TaskBarLocationProvider
{
    // P/Invoke goo:
    private const int ABM_GETTASKBARPOS = 5;

    [DllImport("shell32.dll")]
    private static extern IntPtr SHAppBarMessage(int msg, ref AppBarData data);

    /// <summary>
    /// Where is task bar located (at top of the screen, at bottom (default), or at the one of sides)
    /// </summary>
    private enum Dock
    {
        Left = 0,
        Top = 1,
        Right = 2,
        Bottom = 3
    }

    private struct Rect
    {
        public int Left, Top, Right, Bottom;
    }

    private struct AppBarData
    {
        public int cbSize;
        public IntPtr hWnd;
        public int uCallbackMessage;
        public Dock Dock;
        public Rect rc;
        public IntPtr lParam;
    }

    private static Rectangle GetTaskBarCoordinates(Rect rc)
    {
        return new Rectangle(rc.Left, rc.Top,
            rc.Right - rc.Left, rc.Bottom - rc.Top);
    }

    private static AppBarData GetTaskBarLocation()
    {
        var data = new AppBarData();
        data.cbSize = Marshal.SizeOf(data);

        IntPtr retval = SHAppBarMessage(ABM_GETTASKBARPOS, ref data);

        if (retval == IntPtr.Zero)
        {
            throw new Win32Exception("WinAPi Error: does'nt work api method SHAppBarMessage");

        }

        return data;
    }

    private static Screen FindScreenWithTaskBar(Rectangle taskBarCoordinates)
    {
        foreach (var screen in Screen.AllScreens)
        {
            if (screen.Bounds.Contains(taskBarCoordinates))
            {
                return screen;
            }
        }

        return Screen.PrimaryScreen;
    }

    /// <summary>
    /// Calculate wpf window position for place it near to taskbar area
    /// </summary>
    /// <param name="windowWidth">target window height</param>
    /// <param name="windowHeight">target window width</param>
    /// <param name="left">Result left coordinate <see cref="System.Windows.Window.Left"/></param>
    /// <param name="top">Result top coordinate <see cref="System.Windows.Window.Top"/></param>
    public static void CalculateWindowPositionByTaskbar(double windowWidth, double windowHeight, out double left, out double top)
    {
        var taskBarLocation = GetTaskBarLocation();
        var taskBarRectangle = GetTaskBarCoordinates(taskBarLocation.rc);
        var screen = FindScreenWithTaskBar(taskBarRectangle);

        left = taskBarLocation.Dock == Dock.Left
            ? screen.Bounds.X + taskBarRectangle.Width
            : screen.Bounds.X + screen.WorkingArea.Width - windowWidth;

        top = taskBarLocation.Dock == Dock.Top
            ? screen.Bounds.Y + taskBarRectangle.Height
            : screen.Bounds.Y + screen.WorkingArea.Height - windowHeight;
    }

and usage in xaml.cs

    private void SetWindowPosition()
    {
        double left, right;
        TaskBarLocationProvider.CalculateWindowPositionByTaskbar(this.Width, this.Height, out left, out right);

        Left = left;
        Top = right;
    }

Open WPF window near to notification area with support multiply monitors

1 Answers1