Ribbon button click event not working

I am new in wpf. I want to try your Fluent ribbon that’s why downloaded it from Nuget and added it to my project. here is my code:

<Fluent:RibbonWindow x:Class="Fluent.Sample.Foundation.Window"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"     
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"     
xmlns:Fluent="clr-namespace:Fluent;assembly=Fluent" 
Title="Fluent.Sample.Foundation" Width="800" Height="600" WindowStartupLocation="CenterScreen" >


<Fluent:Ribbon>
    <!--Backstage-->
    <Fluent:Ribbon.Menu>
        <Fluent:Backstage></Fluent:Backstage>
    </Fluent:Ribbon.Menu>
    <!--Tabs-->
    <Fluent:RibbonTabItem Header="Tab">
        <Fluent:RibbonGroupBox Header="Group">
            <Fluent:Button Name="buttonGreen" Header="Green" Icon="Images\Green.png" LargeIcon="Images\GreenLarge.png"/>
            <Fluent:Button Name="buttonGray" Header="Grey" Icon="Images\Gray.png" LargeIcon="Images\GrayLarge.png" Click="btnClick" />
        </Fluent:RibbonGroupBox>
    </Fluent:RibbonTabItem>
</Fluent:Ribbon>
 </Fluent:RibbonWindow>  

---

**MainWindow.xaml.vb**
Class MainWindow 
Private Sub btnClick(sender As Object, e As RoutedEventArgs)
    MsgBox("test")
End Sub
End Class

But i get this error.

Type 'Fluent.RibbonWindow' is not defined.
Type 'Fluent.Button' is not defined.
'btnClick' is not a member of 'TestRibbon.Fluent.Sample.Foundation.Window'.

when i change Fluent.RibbonWindow to **Global.Fluent.RibbonWindow _and same thing with _Fluent.Button it works well and after some time it again show the same error and i can’t understand why this error occurred ‘btnClick’ is not a member of ‘TestRibbon.Fluent.Sample.Foundation.Window’. I am using vs2013. Can you tell me if I have done anything wrong? Thanks

[batzen]

Ok, VB.NET seems to behave different. You need to use:

x:Class="MainWindow"

[batzen]

That reference was, of course, wrong.