Click here to Skip to main content
Click here to Skip to main content
Add your own
alternative version

Creating an application like Google Desktop in WPF and C#

, 28 Jul 2011
This article explains how to create an application like Google Desktop in WPF.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Runtime.InteropServices;
using System.Windows.Interop;

namespace Appbar
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        #region Window Docking

        [DllImport("SHELL32", CallingConvention = CallingConvention.StdCall)]
        static extern uint SHAppBarMessage(int dwMessage, ref APPBARDATA pData);
        [DllImport("User32.dll", ExactSpelling = true, CharSet = System.Runtime.InteropServices.CharSet.Auto)]
        private static extern bool MoveWindow(IntPtr hWnd, int x, int y, int cx, int cy, bool repaint);
        [DllImport("User32.dll", CharSet = CharSet.Auto)]
        private static extern int RegisterWindowMessage(string msg);
        const int ABM_NEW = 0;
        const int ABM_REMOVE = 1;
        const int ABM_QUERYPOS = 2;
        const int ABM_SETPOS = 3;
        const int ABM_GETSTATE = 4;
        const int ABM_GETTASKBARPOS = 5;
        const int ABM_ACTIVATE = 6;
        const int ABM_GETAUTOHIDEBAR = 7;
        const int ABM_SETAUTOHIDEBAR = 8;
        const int ABM_WINDOWPOSCHANGED = 9;
        const int ABM_SETSTATE = 10;
        const int ABN_STATECHANGE = 0;
        const int ABN_POSCHANGED = 1;
        const int ABN_FULLSCREENAPP = 2;
        const int ABN_WINDOWARRANGE = 3;
        const int ABE_LEFT = 0;
        const int ABE_TOP = 1;
        const int ABE_RIGHT = 2;
        const int ABE_BOTTOM = 3;
        [StructLayout(LayoutKind.Sequential)]
        struct RECT
        {
            public int left;
            public int top;
            public int right;
            public int bottom;
        }
        [StructLayout(LayoutKind.Sequential)]
        struct APPBARDATA
        {
            public int cbSize;
            public IntPtr hWnd;
            public int uCallbackMessage;
            public int uEdge;
            public RECT rc;
            public IntPtr lParam;
        }

        // Is AppBar registered?
        bool fBarRegistered = false;

        // Number of AppBar's message for WndProc
        int uCallBack;

        // Register AppBar
        void RegisterBar()
        {
            WindowInteropHelper helper = new WindowInteropHelper(this);
            HwndSource mainWindowSrc = (HwndSource)HwndSource.FromHwnd(helper.Handle);

            APPBARDATA abd = new APPBARDATA();
            abd.cbSize = Marshal.SizeOf(abd);
            abd.hWnd = mainWindowSrc.Handle;

            if (!fBarRegistered)
            {
                uCallBack = RegisterWindowMessage("AppBarMessage");
                abd.uCallbackMessage = uCallBack;

                uint ret = SHAppBarMessage(ABM_NEW, ref abd);
                fBarRegistered = true;

                ABSetPos();
            }
        }
        // Unregister AppBar
        void UnregisterBar()
        {
            WindowInteropHelper helper = new WindowInteropHelper(this);
            HwndSource mainWindowSrc = (HwndSource)HwndSource.FromHwnd(helper.Handle);

            APPBARDATA abd = new APPBARDATA();
            abd.cbSize = Marshal.SizeOf(abd);
            abd.hWnd = mainWindowSrc.Handle;

            if (fBarRegistered)
            {
                SHAppBarMessage(ABM_REMOVE, ref abd);
                fBarRegistered = false;
            }
        }
        // Set position of AppBar
        void ABSetPos()
        {
            if (fBarRegistered)
            {
                WindowInteropHelper helper = new WindowInteropHelper(this);
                HwndSource mainWindowSrc = (HwndSource)HwndSource.FromHwnd(helper.Handle);

                APPBARDATA abd = new APPBARDATA();
                abd.cbSize = Marshal.SizeOf(abd);
                abd.hWnd = mainWindowSrc.Handle;
                abd.uEdge = Properties.Settings.Default.uEdge;

                if (abd.uEdge == ABE_LEFT || abd.uEdge == ABE_RIGHT)
                {
                    abd.rc.top = 0;
                    abd.rc.bottom = (int)SystemParameters.PrimaryScreenHeight;
                    if (abd.uEdge == ABE_LEFT)
                    {
                        abd.rc.left = 0;
                        abd.rc.right = (int)this.ActualWidth;
                    }
                    else
                    {
                        abd.rc.right = (int)SystemParameters.PrimaryScreenWidth;
                        abd.rc.left = abd.rc.right - (int)this.ActualWidth;
                    }
                }
                else
                {
                    abd.rc.left = 0;
                    abd.rc.right = (int)SystemParameters.PrimaryScreenWidth;
                    if (abd.uEdge == ABE_TOP)
                    {
                        abd.rc.top = 0;
                        abd.rc.bottom = (int)this.ActualHeight;
                    }
                    else
                    {
                        abd.rc.bottom = (int)SystemParameters.PrimaryScreenHeight;
                        abd.rc.top = abd.rc.bottom - (int)this.ActualHeight;
                    }
                }

                SHAppBarMessage(ABM_QUERYPOS, ref abd);

                SHAppBarMessage(ABM_SETPOS, ref abd);
                MoveWindow(abd.hWnd, abd.rc.left, abd.rc.top, abd.rc.right - abd.rc.left, abd.rc.bottom - abd.rc.top, true);
            }
        }

        #endregion

        #region Glass extending

        [StructLayout(LayoutKind.Sequential)]
        struct MARGINS
        {
            public int cxLeftWidth;
            public int cxRightWidth;
            public int cyTopHeight;
            public int cyBottomHeight;
        }
        [DllImport("dwmapi.dll")]
        static extern int DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS pMarInset);
        [DllImport("dwmapi.dll")]
        extern static int DwmIsCompositionEnabled(ref int en);
        const int WM_DWMCOMPOSITIONCHANGED = 0x031E;

        void ExtendGlass()
        {
            try
            {
                int isGlassEnabled = 0;
                DwmIsCompositionEnabled(ref isGlassEnabled);
                if (Environment.OSVersion.Version.Major > 5 && isGlassEnabled > 0)
                {
                    WindowInteropHelper helper = new WindowInteropHelper(this);
                    HwndSource mainWindowSrc = (HwndSource)HwndSource.FromHwnd(helper.Handle);

                    mainWindowSrc.CompositionTarget.BackgroundColor = Colors.Transparent;
                    this.Background = Brushes.Transparent;

                    MARGINS margins = new MARGINS();
                    margins.cxLeftWidth = -1;
                    margins.cxRightWidth = -1;
                    margins.cyBottomHeight = -1;
                    margins.cyTopHeight = -1;

                    DwmExtendFrameIntoClientArea(mainWindowSrc.Handle, ref margins);
                }
            }
            catch (DllNotFoundException) { }
        }

        #endregion

        const int WM_NCLBUTTONDOWN = 0x00A1;
        const int WM_EXITSIZEMOVE = 0x0232;

        TransPrev tp = new TransPrev();
        bool nclbd = false;

        IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
        {
            if (msg == uCallBack && wParam.ToInt32() == ABN_POSCHANGED)
            {
                ABSetPos();
                handled = true;
            }
            else if (msg == WM_DWMCOMPOSITIONCHANGED)
            {
                ExtendGlass();
                handled = true;
            }
            else if (msg == WM_NCLBUTTONDOWN)
            {
                nclbd = true;
            }
            else if (msg == WM_EXITSIZEMOVE)
            {
                nclbd = false;
                tp.Hide();
                CalculateHorizontalEdge();
                RegisterBar();
            }
            return IntPtr.Zero;
        }

        private void Window_LocationChanged(object sender, EventArgs e)
        {
            if (nclbd)
            {
                if (fBarRegistered)
                {
                    UnregisterBar();
                    tp.Show();
                }
                RefreshTransPrev();
            }
        }

        void RefreshTransPrev()
        {
            CalculateHorizontalEdge();
            tp.SetArrow(Properties.Settings.Default.uEdge);
        }

        void CalculateHorizontalEdge()
        {
            if (SystemParameters.PrimaryScreenWidth / 2 > this.Left)
                Properties.Settings.Default.uEdge = ABE_LEFT;
            else
                Properties.Settings.Default.uEdge = ABE_RIGHT;
            Properties.Settings.Default.Save();
        }

        protected override void OnSourceInitialized(EventArgs e)
        {
            base.OnSourceInitialized(e);

            IntPtr hwnd = new WindowInteropHelper(this).Handle;
            HwndSource source = HwndSource.FromHwnd(hwnd);
            source.AddHook(new HwndSourceHook(WndProc));

            ExtendGlass();
            RegisterBar();
        }

        private void Window_Closing(object sender, System.ComponentModel.CancelEventArgs e)
        {
            UnregisterBar();
            Application.Current.Shutdown();
        }
    }
}

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

TeapotDev

Poland Poland

My homepage
Follow on   Twitter

| Advertise | Privacy | Mobile
Web04 | 2.8.140721.1 | Last Updated 28 Jul 2011
Article Copyright 2011 by TeapotDev
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid