Design-time failure: WPF, Usercontrols and Namespaces

I have a very simple WPF project comprising a Window and Usercontrol. I'm very much in a learning phase. It works fine when I run it. However, I am unable to see the form in design time. The problem, I believe is something to do with namespaces, but I don't understand where. It may well be a simple error

Main Window XML

<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" 
    xmlns:views="clr-namespace:UserLogin"
    x:Class="UserLogin.MainView"
    x:Name="MainViewWindow"
    mc:Ignorable="d" 
    Title="Login" 
    Height="141" 
    Width="347"
    >

    <Grid>        
        <views:LoginView />
    </Grid>

</Window>

Main Window CodeBehind

Imports Microsoft.VisualBasic
Imports System
Imports System.Windows
Imports UserLogin

Namespace UserLogin

    Partial Public Class MainView
        Inherits System.Windows.Window

        Public Sub New()
            InitializeComponent()
        End Sub

    End Class

End Namespace

Usercontrol XAML

<UserControl xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             x:Class="UserLogin.LoginView"
             x:Name="LoginViewControl"
             mc:Ignorable="d" d:DesignHeight="96" d:DesignWidth="298">
    <Grid  Height="96" Width="298">
        <Button Command="{Binding OKCommand}" Height="21" Margin="0,0,90,16" Name="btnOK" VerticalAlignment="Bottom" HorizontalAlignment="Right" Width="76开发者_Python百科">OK</Button>
        <Button Command="{Binding CancelCommand}" Height="21" HorizontalAlignment="Right" Margin="0,0,9,16" Name="btnCancel" VerticalAlignment="Bottom" Width="75">Cancel</Button>
        <Label Height="23" HorizontalAlignment="Left" Margin="10,5,0,0" Name="Label1" VerticalAlignment="Top" Width="85">Name:</Label>
        <Label HorizontalAlignment="Left" Margin="10,32,0,0" Name="Label2" Width="85" Height="29" VerticalAlignment="Top">Password:</Label>
        <TextBox Margin="0,31,6,0" Name="txtPassword" Height="22" VerticalAlignment="Top" HorizontalAlignment="Right" Width="182" />
        <ComboBox Height="22" Margin="110,6,6,0" Name="cboNames" VerticalAlignment="Top" />
    </Grid>
</UserControl>

Usercontrol CodeBehind

Imports Microsoft.VisualBasic
Imports System
Imports UserLogin

Namespace UserLogin
    Partial Public Class LoginView
        Inherits System.Windows.Controls.UserControl

        Public Sub New()
            InitializeComponent()
        End Sub

    End Class
End Namespace

I think I'm missing something this namespace

xmlns:views="clr-namespace:UserLogin"

since intellisense doesn't give me the usercontrol declared within it in the XAML designer but rather reports the error "Unable to load the metadata for the assembly ... etc etc"

Thx for any suggestions

Simon

I had this issue and figured it out. I got the error in the designer, but it worked when running the program. In this instance, the source code was on a network drive and that drive did not have full trust permission. I moved the code locally and it started working. You could also add full trust permission if you prefer to keep your code on the network drive.

This may be a stupid question, but did you rebuild your project after creating the control? The Visual Studio WPF editor is incredibly finicky about finding assemblies, but "can't find metadata" almost always means that the assembly you're referencing doesn't exist.
Whenever you have a weird WPF designer issue, always rebuild and possibly restart VS.

are MainView and LoginView controls in the same assembly? If not, you need to include assembly info in the name space defn.