Native Aero Blur without Glass Effect on Borderless WPF Window

Question

I am aware that similar questions have been asked and answered. Mine, however, is a three-part question.

For the purposes of this question, keep the following in mind:

Answer 1

1. Applying Aero Glass to Borderless Window

Since what you are trying to achieve is not so much a glass effect but more of a transparent+blur you can use the following methods to blur behind the window.

Windows 7: you can use DwmEnableBlurBehindWindow to blur behind the window.

Window 8: I havn't found a workable solution since DwmEnableBlurBehindWindow was removed in Windows 8.

Windows 10: you can use SetWindowCompositionAttribute to blur behind the window.

2. Keeping Native Blur Effect without Glass

The above solutions will only apply a blur effect behind the window, it will be up to the window to define transparency and colour.

3. Customizing Blur Radius and Location

With these approaches you can only blur underneath the entire window, and it will be up to you to use an alpha channel on portions of the window you want to be transparent. I don't think you can define the blur radius either.

Answer 2

My Excuse

Pardon my inexperience with Stackoverflow but I thought I would try and help you out a little.

By following the link posted by Tom I was able to come across this block of code (originally in c#). So seen as how this code isn't readily availible to most people, here it is:

Imports System.Runtime.InteropServices
Imports System.Windows.Interop
'Import namespace ("name of project" . "name of namespace")
Imports Blurred_Opacity.BlurBehind

Namespace BlurTest
    Enum AccentState
        ACCENT_DISABLED = 0
        ACCENT_ENABLE_GRADIENT = 1
        ACCENT_ENABLE_TRANSPARENTGRADIENT = 2
        ACCENT_ENABLE_BLURBEHIND = 3
        ACCENT_INVALID_STATE = 4
    End Enum

    Structure AccentPolicy
        Public AccentState As AccentState
        Public AccentFlags As Integer
        Public GradientColor As Integer
        Public AnimationId As Integer
    End Structure

    Structure WindowCompositionAttributeData
        Public Attribute As WindowCompositionAttribute
        Public Data As IntPtr
        Public SizeOfData As Integer
    End Structure

    Enum WindowCompositionAttribute
        WCA_ACCENT_POLICY = 19
    End Enum
End Namespace

Class MainWindow
    <DllImport("user32.dll")>
    Friend Shared Function SetWindowCompositionAttribute(hwnd As IntPtr, ByRef data As WindowCompositionAttributeData) As Integer
    End Function

    Sub Window_Loaded() handles me.loaded
        EnableBlur()
    End Sub
    Sub Window_MouseDown() handles me.MouseLeftButtonDown
        DragMove()
    End Sub

    Sub EnableBlur()
        Dim windowHelper = New WindowInteropHelper(Me)
        Dim accent = New AccentPolicy()
        accent.AccentState = AccentState.ACCENT_ENABLE_BLURBEHIND
        Dim accentStructSize = Marshal.SizeOf(accent)
        Dim accentPtr = Marshal.AllocHGlobal(accentStructSize)
        Marshal.StructureToPtr(accent, accentPtr, False)
        Dim Data = New WindowCompositionAttributeData()
        Data.Attribute = WindowCompositionAttribute.WCA_ACCENT_POLICY
        Data.SizeOfData = accentStructSize
        Data.Data = accentPtr
        SetWindowCompositionAttribute(windowHelper.Handle, Data)
        Marshal.FreeHGlobal(accentPtr)
    End Sub
End Class

Result

Once implemented, this will effect the whole Window as shown:

After a little tweaking

After about 5 mins of trying to copy your design I came up with this:

XAML

I'm sure you could do a better job of the design than I have. It is possible to change the blend colour simply by adjusting the background colour (on the window), and the opacity level can also be changed. The XAML of my design is as follows:

<Window
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d" x:Class="MainWindow"
    Title="Blurred Opacity" Height="623" Width="752"
    Background="#727A7A7A"
    AllowsTransparency="True"
    WindowStyle="None"
    BorderThickness="1"
    WindowStartupLocation="CenterScreen"
    Loaded="Window_Loaded" MouseLeftButtonDown="Window_MouseDown" Topmost="True" BorderBrush="#FF1E9EC5">
<Grid>
    <Rectangle Fill="#FF0143A4" Height="130" VerticalAlignment="Top"/>
    <Rectangle Fill="White" Margin="0,130,0,0" HorizontalAlignment="Right" Width="375"/>
    <StackPanel HorizontalAlignment="Left" Margin="0,130,0,0" Width="375">
        <TextBlock x:Name="textBlock" Height="50" TextWrapping="Wrap" Text="Category 1" d:LayoutOverrides="LeftPosition, RightPosition" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6"/>
        <TextBlock x:Name="textBlock_Copy" Height="50" TextWrapping="Wrap" Text="Category 2" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"/>
        <TextBlock x:Name="textBlock_Copy1" Height="50" TextWrapping="Wrap" Text="Category 3" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"/>
        <TextBlock x:Name="textBlock_Copy2" Height="50" TextWrapping="Wrap" Text="Category 4" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"/>
        <TextBlock x:Name="textBlock_Copy3" Height="50" TextWrapping="Wrap" Text="Category 5" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"/>
        <TextBlock x:Name="textBlock_Copy4" Height="50" TextWrapping="Wrap" Text="Category 6" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"/>
        <TextBlock x:Name="textBlock_Copy5" Height="50" TextWrapping="Wrap" Text="Category 7" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"/>
        <TextBlock x:Name="textBlock_Copy6" Height="50" TextWrapping="Wrap" Text="Category 8" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"/>
    </StackPanel>
    <TextBlock x:Name="textBlock_Copy7" Height="90" TextWrapping="Wrap" Text="Example" FontSize="65" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" Margin="222.5,23,152.5,0" VerticalAlignment="Top" Foreground="White"/>
    <Path Data="M705,27.333333 L735.66667,10" Fill="White" HorizontalAlignment="Right" Height="24" Margin="0,7,21,0" Stretch="Fill" VerticalAlignment="Top" Width="24" StrokeThickness="3" Stroke="White"/>
    <Path Data="M705,27.333333 L735.66667,10" Fill="White" HorizontalAlignment="Right" Height="24.083" Margin="0,6.833,20.333,0" Stretch="Fill" VerticalAlignment="Top" Width="24.167" StrokeThickness="3" Stroke="White" RenderTransformOrigin="0.5,0.5">
        <Path.RenderTransform>
            <TransformGroup>
                <ScaleTransform ScaleX="-1"/>
                <SkewTransform/>
                <RotateTransform/>
                <TranslateTransform/>
            </TransformGroup>
        </Path.RenderTransform>
    </Path>
    <StackPanel HorizontalAlignment="Right" Margin="0,130,0,0" Width="375">
        <TextBlock x:Name="textBlock1" Height="50" TextWrapping="Wrap" Text="Item 1" d:LayoutOverrides="LeftPosition, RightPosition" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6"/>
        <TextBlock x:Name="textBlock_Copy8" Height="50" TextWrapping="Wrap" Text="Item 2" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"/>
        <TextBlock x:Name="textBlock_Copy9" Height="50" TextWrapping="Wrap" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"><Run Text="Item "/><Run Text="3"/><LineBreak/><Run Text="3"/></TextBlock>
        <TextBlock x:Name="textBlock_Copy10" Height="50" TextWrapping="Wrap" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"><Run Text="Item "/><Run Text="4"/></TextBlock>
        <TextBlock x:Name="textBlock_Copy11" Height="50" TextWrapping="Wrap" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"><Run Text="Item "/><Run Text="5"/></TextBlock>
        <TextBlock x:Name="textBlock_Copy12" Height="50" TextWrapping="Wrap" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"><Run Text="Item "/><Run Text="6"/></TextBlock>
        <TextBlock x:Name="textBlock_Copy13" Height="50" TextWrapping="Wrap" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"><Run Text="Item "/><Run Text="7"/></TextBlock>
        <TextBlock x:Name="textBlock_Copy14" Height="50" TextWrapping="Wrap" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"><Run Text="Item "/><Run Text="8"/></TextBlock>
        <TextBlock x:Name="textBlock_Copy15" Height="50" TextWrapping="Wrap" FontSize="35" Padding="10,0,0,0" TextOptions.TextFormattingMode="Display" LineHeight="6" d:LayoutOverrides="LeftPosition, RightPosition"><Run Text="Item "/><Run Text="9"/></TextBlock>
    </StackPanel>
</Grid>

I hope this helps!