Is there any complete guidance on doing AppBar docking (such as locking to the screen edge) in WPF? I understand there are InterOp calls that need to be made, but I'm looking for either a proof of concept based on a simple WPF form, or a componentized version that can be consumed.
Related resources:
I took the code from the first link provided in the question ( http://www.codeproject.com/KB/dotnet/AppBar.aspx ) and modified it to do two things:
This approach doesn't create a base class.
To use, just call this code from anywhere within a normal wpf window (say a button click or the initialize). Note that you can not call this until AFTER the window is initialized, if the HWND hasn't been created yet (like in the constructor), an error will occur.
Make the window an appbar:
AppBarFunctions.SetAppBar( this, ABEdge.Right );
Restore the window to a normal window:
AppBarFunctions.SetAppBar( this, ABEdge.None );
Here's the full code to the file - note you'll want to change the namespace on line 7 to something apropriate.
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Threading;
namespace AppBarApplication
{
public enum ABEdge : int
{
Left = 0,
Top,
Right,
Bottom,
None
}
internal static class AppBarFunctions
{
[StructLayout(LayoutKind.Sequential)]
private struct RECT
{
public int left;
public int top;
public int right;
public int bottom;
}
[StructLayout(LayoutKind.Sequential)]
private struct APPBARDATA
{
public int cbSize;
public IntPtr hWnd;
public int uCallbackMessage;
public int uEdge;
public RECT rc;
public IntPtr lParam;
}
private enum ABMsg : int
{
ABM_NEW = 0,
ABM_REMOVE,
ABM_QUERYPOS,
ABM_SETPOS,
ABM_GETSTATE,
ABM_GETTASKBARPOS,
ABM_ACTIVATE,
ABM_GETAUTOHIDEBAR,
ABM_SETAUTOHIDEBAR,
ABM_WINDOWPOSCHANGED,
ABM_SETSTATE
}
private enum ABNotify : int
{
ABN_STATECHANGE = 0,
ABN_POSCHANGED,
ABN_FULLSCREENAPP,
ABN_WINDOWARRANGE
}
[DllImport("SHELL32", CallingConvention = CallingConvention.StdCall)]
private static extern uint SHAppBarMessage(int dwMessage, ref APPBARDATA pData);
[DllImport("User32.dll", CharSet = CharSet.Auto)]
private static extern int RegisterWindowMessage(string msg);
private class RegisterInfo
{
public int CallbackId { get; set; }
public bool IsRegistered { get; set; }
public Window Window { get; set; }
public ABEdge Edge { get; set; }
public WindowStyle OriginalStyle { get; set; }
public Point OriginalPosition { get; set; }
public Size OriginalSize { get; set; }
public ResizeMode OriginalResizeMode { get; set; }
public IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam,
IntPtr lParam, ref bool handled)
{
if (msg == CallbackId)
{
if (wParam.ToInt32() == (int)ABNotify.ABN_POSCHANGED)
{
ABSetPos(Edge, Window);
handled = true;
}
}
return IntPtr.Zero;
}
}
private static Dictionary<Window, RegisterInfo> s_RegisteredWindowInfo
= new Dictionary<Window, RegisterInfo>();
private static RegisterInfo GetRegisterInfo(Window appbarWindow)
{
RegisterInfo reg;
if( s_RegisteredWindowInfo.ContainsKey(appbarWindow))
{
reg = s_RegisteredWindowInfo[appbarWindow];
}
else
{
reg = new RegisterInfo()
{
CallbackId = 0,
Window = appbarWindow,
IsRegistered = false,
Edge = ABEdge.Top,
OriginalStyle = appbarWindow.WindowStyle,
OriginalPosition =new Point( appbarWindow.Left, appbarWindow.Top),
OriginalSize =
new Size( appbarWindow.ActualWidth, appbarWindow.ActualHeight),
OriginalResizeMode = appbarWindow.ResizeMode,
};
s_RegisteredWindowInfo.Add(appbarWindow, reg);
}
return reg;
}
private static void RestoreWindow(Window appbarWindow)
{
RegisterInfo info = GetRegisterInfo(appbarWindow);
appbarWindow.WindowStyle = info.OriginalStyle;
appbarWindow.ResizeMode = info.OriginalResizeMode;
appbarWindow.Topmost = false;
Rect rect = new Rect(info.OriginalPosition.X, info.OriginalPosition.Y,
info.OriginalSize.Width, info.OriginalSize.Height);
appbarWindow.Dispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle,
new ResizeDelegate(DoResize), appbarWindow, rect);
}
public static void SetAppBar(Window appbarWindow, ABEdge edge)
{
RegisterInfo info = GetRegisterInfo(appbarWindow);
info.Edge = edge;
APPBARDATA abd = new APPBARDATA();
abd.cbSize = Marshal.SizeOf(abd);
abd.hWnd = new WindowInteropHelper(appbarWindow).Handle;
if( edge == ABEdge.None)
{
if( info.IsRegistered)
{
SHAppBarMessage((int)ABMsg.ABM_REMOVE, ref abd);
info.IsRegistered = false;
}
RestoreWindow(appbarWindow);
return;
}
if (!info.IsRegistered)
{
info.IsRegistered = true;
info.CallbackId = RegisterWindowMessage("AppBarMessage");
abd.uCallbackMessage = info.CallbackId;
uint ret = SHAppBarMessage((int)ABMsg.ABM_NEW, ref abd);
HwndSource source = HwndSource.FromHwnd(abd.hWnd);
source.AddHook(new HwndSourceHook(info.WndProc));
}
appbarWindow.WindowStyle = WindowStyle.None;
appbarWindow.ResizeMode = ResizeMode.NoResize;
appbarWindow.Topmost = true;
ABSetPos(info.Edge, appbarWindow);
}
private delegate void ResizeDelegate(Window appbarWindow, Rect rect);
private static void DoResize(Window appbarWindow, Rect rect)
{
appbarWindow.Width = rect.Width;
appbarWindow.Height = rect.Height;
appbarWindow.Top = rect.Top;
appbarWindow.Left = rect.Left;
}
private static void ABSetPos(ABEdge edge, Window appbarWindow)
{
APPBARDATA barData = new APPBARDATA();
barData.cbSize = Marshal.SizeOf(barData);
barData.hWnd = new WindowInteropHelper(appbarWindow).Handle;
barData.uEdge = (int)edge;
if (barData.uEdge == (int)ABEdge.Left || barData.uEdge == (int)ABEdge.Right)
{
barData.rc.top = 0;
barData.rc.bottom = (int)SystemParameters.PrimaryScreenHeight;
if (barData.uEdge == (int)ABEdge.Left)
{
barData.rc.left = 0;
barData.rc.right = (int)Math.Round(appbarWindow.ActualWidth);
}
else
{
barData.rc.right = (int)SystemParameters.PrimaryScreenWidth;
barData.rc.left = barData.rc.right - (int)Math.Round(appbarWindow.ActualWidth);
}
}
else
{
barData.rc.left = 0;
barData.rc.right = (int)SystemParameters.PrimaryScreenWidth;
if (barData.uEdge == (int)ABEdge.Top)
{
barData.rc.top = 0;
barData.rc.bottom = (int)Math.Round(appbarWindow.ActualHeight);
}
else
{
barData.rc.bottom = (int)SystemParameters.PrimaryScreenHeight;
barData.rc.top = barData.rc.bottom - (int)Math.Round(appbarWindow.ActualHeight);
}
}
SHAppBarMessage((int)ABMsg.ABM_QUERYPOS, ref barData);
SHAppBarMessage((int)ABMsg.ABM_SETPOS, ref barData);
Rect rect = new Rect((double)barData.rc.left, (double)barData.rc.top,
(double)(barData.rc.right - barData.rc.left), (double)(barData.rc.bottom - barData.rc.top));
//This is done async, because WPF will send a resize after a new appbar is added.
//if we size right away, WPFs resize comes last and overrides us.
appbarWindow.Dispatcher.BeginInvoke(DispatcherPriority.ApplicationIdle,
new ResizeDelegate(DoResize), appbarWindow, rect);
}
}
}
Very happy to have found this question. Above class is really useful, but doesnt quite cover all the bases of AppBar implementation.
To fully implement all the behaviour of an AppBar (cope with fullscreen apps etc) you're going to want to read this MSDN article too.
Thank you for posting this code, Philip Rieck; I found it a very good starting point.
I did notice that there were errors when sizing an AppBar that was docked adjacent to the start menu (at either the bottom or top of the screen), and made the following changes. Does anyone else know if there is an equivalent WPF construct for Forms.Screen?
if (barData.uEdge == (int)ABEdge.Top)
{
barData.rc.top = System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Top;
barData.rc.bottom = System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Top + (int)Math.Round(appbarWindow.ActualHeight);
}
else
{
barData.rc.bottom = (int)System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Bottom;
barData.rc.top = barData.rc.bottom - (int)Math.Round(appbarWindow.ActualHeight);
}
Sorry, the last code I posted didn't work when the Taskbar is resized. The following code change seems to work better:
SHAppBarMessage((int)ABMsg.ABM_QUERYPOS, ref barData); if (barData.uEdge == (int)ABEdge.Top) barData.rc.bottom = barData.rc.top + (int)Math.Round(appbarWindow.ActualHeight); else if (barData.uEdge == (int)ABEdge.Bottom) barData.rc.top = barData.rc.bottom - (int)Math.Round(appbarWindow.ActualHeight); SHAppBarMessage((int)ABMsg.ABM_SETPOS, ref barData);
As a commercial alternative, see the ready-to-use ShellAppBar component for WPF which supports all cases and secnarios such as taskbar docked to left,right,top,bottom edge, support for multiple monitors, drag-docking, autohide , etc etc. It may save you time and money over trying to handle all these cases yourself.