WPF borderless window with shadow VS2012 style

Question

I\'m trying to create an application that looks like Visual Studio 2012. I have used WindowChrome to remove the window borders, and changed the border color in my xaml.

Answer 1

Update (October '17)

It has been four years now and I was interested in tackling this again and thus I have been messing around with MahApps.Metro once again and derived my own library based on it. My ModernChrome library provides a custom window that looks like Visual Studio 2017:

Since you are most likely only interested in the part about the glowing border, you should either use MahApps.Metro itself or see how I created a class GlowWindowBehavior which attaches glow borders to my custom ModernWindow class. It is hevily dependant on some internals of MahApps.Metro and the two dependency properties GlowBrush and NonActiveGlowBrush.

If you only want to include the glowing borders to your custom applications just reference MahApps.Metro and copy over my GlowWindowBehavior.cs and create a custom window class and adapt the references accordingly. This is a matter of 15 minutes at most.

This question and my answer have been accessed very frequently so I hope you will find my newest proper solution useful :)

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Original post (February '13)

I have been working on such a library to copy the Visual Studio 2012 user interface. A custom chrome isn't that difficult but what you should take care of is this glowing border which is hard to implement. You could just say set the background color of your window to transparent and set the padding of the main grid to about 30px. A border around the grid could be colored and associated with a colored shadow effect but this approach forces you to set AllowsTransparency to true which drastically reduces visual performance of your application and this is something you definitely do not want to do!

My current approach to create such a window which just has a colored shadow effect on a border and is transparent but has no content at all. Evertime the position of my main window changes I just update the position of the window which holds the border. So in the end I am handling two windows with messages to fake that the border would be part of the main window. This was necessary because the DWM library doesn't provide a way to have a colored drop shadow effect for windows and I think Visual Studio 2012 does that similiar like I tried.

And to extend this post with more information: Office 2013 does that differently. The border around a window is just 1px thick and colored, yet the shadow is drawn by DWM with a code like this one here. If you can live without having blue/purple/green borders and just usual ones this is the approach I would choose! Just don't set AllowsTransparency to true, otherwise you have lost.

And here is a screenshot of my window with strange color to highlight what it looks like:

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Here are some hints on how to start

Please keep in mind that my code is quite long, such that I will only be able to show you the basic things to do and you should be able to at least start somehow. First of all I'm going to assume that we have designed our main window somehow (either manually or with the MahApps.Metro package I tried out yesterday - with some modifications to the sourcecode this is really good⁽¹⁾) and we are currently working to implement the glowing shadow border, which I will call GlowWindow from now on. The easiest approach is to create a window with the following XAML code

The resulting window should look like the following picture.

The next steps are quite difficult - when our main window spawns we want to make the GlowWindow visible but behind the main window and we have to update the position of the GlowWindow when the main window is being moved or resized. What I suggest to prevent visual glitches that can AND will occur is to hide the GlowWindow during every change of either location or size of the window. Once finished with such action just show it again.

I have some method which is called in different situations (it might be a lot but just to get sure)

private void UpdateGlowWindow(bool isActivated = false) {
    if(this.DisableComposite || this.IsMaximized) {
        this.glowWindow.Visibility = System.Windows.Visibility.Collapsed;
        return;
    }
    try {
        this.glowWindow.Left = this.Left - 10;
        this.glowWindow.Top = this.Top - 10;
        this.glowWindow.Width = this.Width + 20;
        this.glowWindow.Height = this.Height + 20;
        this.glowWindow.Visibility = System.Windows.Visibility.Visible;
        if(!isActivated)
            this.glowWindow.Activate();
    } catch(Exception) {
    }
}

This method is mainly called in my custom WndProc I have attached to the main window:

/// 

/// An application-defined function that processes messages sent to a window. The WNDPROC type
/// defines a pointer to this callback function.
/// 
/// A handle to the window.
/// The message.
/// Additional message information. The contents of this parameter depend on
/// the value of the uMsg parameter.
/// Additional message information. The contents of this parameter depend on
/// the value of the uMsg parameter.
/// Reference to boolean value which indicates whether a message was handled.
/// 
/// The return value is the result of the message processing and depends on the message sent.
/// 
private IntPtr WindowProc(IntPtr hwnd, int uMsg, IntPtr wParam, IntPtr lParam, ref bool handled) {
    // BEGIN UNMANAGED WIN32
    switch((WinRT.Message)uMsg) {
        case WinRT.Message.WM_SIZE:
            switch((WinRT.Size)wParam) {
                case WinRT.Size.SIZE_MAXIMIZED:
                    this.Left = this.Top = 0;
                    if(!this.IsMaximized)
                        this.IsMaximized = true;
                    this.UpdateChrome();
                    break;
                case WinRT.Size.SIZE_RESTORED:
                    if(this.IsMaximized)
                        this.IsMaximized = false;
                    this.UpdateChrome();
                    break;
            }
            break;

        case WinRT.Message.WM_WINDOWPOSCHANGING:
            WinRT.WINDOWPOS windowPosition = (WinRT.WINDOWPOS)Marshal.PtrToStructure(lParam, typeof(WinRT.WINDOWPOS));
            Window handledWindow = (Window)HwndSource.FromHwnd(hwnd).RootVisual;
            if(handledWindow == null)
                return IntPtr.Zero;
            bool hasChangedPosition = false;
            if(this.IsMaximized == true && (this.Left != 0 || this.Top != 0)) {
                windowPosition.x = windowPosition.y = 0;
                windowPosition.cx = (int)SystemParameters.WorkArea.Width;
                windowPosition.cy = (int)SystemParameters.WorkArea.Height;
                hasChangedPosition = true;
                this.UpdateChrome();
                this.UpdateGlowWindow();
            }
            if(!hasChangedPosition)
                return IntPtr.Zero;
            Marshal.StructureToPtr(windowPosition, lParam, true);
            handled = true;
            break;
    }
    return IntPtr.Zero;
    // END UNMANAGED WIN32
}

However there is still an issue left - once you resize your main window the GlowWindow will not be able to cover the whole window with its size. That is if you resize your main window to about MaxWidth of your screen, then the widt of the GlowWindow would be the same value + 20 as I have added a margin of 10 to it. Therefore the right edge would be interrupted right before the right edge of the main window which looks ugly. To prevent this I used a hook to make the GlowWindow a toolwindow:

this.Loaded += delegate {
    WindowInteropHelper wndHelper = new WindowInteropHelper(this);
    int exStyle = (int)WinRT.GetWindowLong(wndHelper.Handle, (int)WinRT.GetWindowLongFields.GWL_EXSTYLE);
    exStyle |= (int)WinRT.ExtendedWindowStyles.WS_EX_TOOLWINDOW;
    WinRT.SetWindowLong(wndHelper.Handle, (int)WinRT.GetWindowLongFields.GWL_EXSTYLE, (IntPtr)exStyle);
};

And still we will have some issues - when you go with the mouse over the GlowWindow and left click it will be activated and get the focus which means it will overlap the main window which looks like this:

To prevent that just catch the Activated event of the border and bring the main window to the foreground.

How should YOU do this?

I suggest NOT to try this out - it took me about a month to achieve what I wanted and still it has some issues, such that I would go for an approach like Office 2013 does - colored border and usual shadow with the DWM API calls - nothing else and still it looks good.

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⁽¹⁾ I have just edited some files to enable the border around the window which is disabled on Window 8 for me. Furthermore I have manipulated the Padding of the title bar such that it doesn't look that sqeezed inplace and lastly I have change the All-Caps property to mimic Visual Studio's way of rendering the title. So far the MahApps.Metro is a better way of drawing the main window as it even supports AeroSnap I couldn't implement with usual P/Invoke calls.