Error: 'Cannot create unknown type '{clr-namespace:NameSpace.Properties}Settings'.'

Question

I define my settings and styles in a ResourceDictionary:

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:properties="clr-namespace:Kavand.UI.Properties">
    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary>
            <properties:Settings x:Key="settings" />
        </ResourceDictionary>
    </ResourceDictionary.MergedDictionaries>
    <Style x:Key="PopupMenu_StackPanel">
        <Setter Property="TextBlock.FontSize" Value="{Binding Source={StaticResource settings}, Path=Default.Font_Menu_Size}" />
        <Setter Property="TextBlock.FontFamily" Value="{Binding Source={StaticResource settings}, Path=Default.Font_Menu_Family}" />
        <Setter Property="TextBlock.FontWeight" Value="{Binding Source={StaticResource settings}, Path=Default.Font_Menu_Weight}" />
        <Style.Resources>
            <Style TargetType="{x:Type MenuItem}" BasedOn="{StaticResource KavandMenuItem}">
                <Style.Triggers>
                    <Trigger Property="IsChecked" Value="true">
                        <Setter Property="IsEnabled" Value="false" />
                    </Trigger>
                    <MultiTrigger>
                        <MultiTrigger.Conditions>
                            <Condition Property="IsChecked" Value="True" />
                            <Condition Property="IsHighlighted" Value="True" />
                        </MultiTrigger.Conditions>
                        <Setter Property="Foreground" Value="{DynamicResource K_Brush_Gray}" />
                    </MultiTrigger>
                </Style.Triggers>
            </Style>
        </Style.Resources>
    </Style>
</ResourceDictionary>

When I run my application, I get the error:

'Cannot create unknown type '{clr-namespace:Kavand.UI.Properties}Settings'.' Line number '6' and line position '14'.

Is it a compile error or a runtime error? Does removing the first three setters allow the application to run? — Adrian, May 27 '11 at 19:36
It is a runtime error, no, just when I remove section that contains definition, application will be compiled — amiry jd, May 27 '11 at 19:37

score 54 · Accepted Answer · edited Jul 23 '15 at 13:12

54

I had set the file's "Build Action" property to "Resource". When I changed it to "Page" the problem was resolved.

edited Jul 23 '15 at 13:12

default

11,485
9
66
102

answered May 28 '11 at 08:21

amiry jd

27,021
30
116
215

3

Waaat? This worked for me too. But the documentation explicitly says to make sure your resource dictionaries have "Resource" build actions. – Kyle Delaney Jun 01 '18 at 17:43

score 51 · Answer 2 · edited Feb 11 '20 at 16:50

51

Keep your "Build Action" property to "Resource" and just change this row:

xmlns:properties="clr-namespace:Kavand.UI.Properties"

with this:

xmlns:properties="clr-namespace:Kavand.UI.Properties;assembly=Kavand.UI"

edited Feb 11 '20 at 16:50

StayOnTarget

11,743
10
52
81

answered Apr 29 '13 at 13:57

Vladimir Trifonov

1,395
11
9

1

I set the build action back to Resource and it worked even without the namespace change. Gaaah! This problem is so fickle. What is up with Visual Studio? – Kyle Delaney Jun 01 '18 at 17:45
Anyone knows when to use Resource and when to use Page? In some other articles using Resource was recommended to solve other mysterious behaviour of user control libraries. – RudolfJan Feb 11 '19 at 20:01

score 4 · Answer 3 · edited Jan 20 '21 at 11:19

4

Just posting another potential solution, because i just recently stumbled over this exception.

It could be that your referenced class-cefinition (in your case Kavand.UI.Properties.Settings) does not use public-access-modifier.

So in my case i could solve this problem by writing public before the class definition.

edited Jan 20 '21 at 11:19

StayOnTarget

11,743
10
52
81

answered Apr 25 '18 at 12:22

lukas hoellriegl

41
2

Thank you! This was the problem I had that lead me to this question. My class was "internal". Changing it to "public" solved my issue. +1 – Nick Oct 17 '20 at 18:24

StayOnTarget · Answer 4 · 2021-01-20T11:19:33.393

3

As a variation on other answers & comments, this worked for me:

Set the file's "Build Action" property to "Page".
Build (problem gone - but...)
Set the file's "Build Action" property to "Resource".
Build
Problem still gone!

Seems like a VS bug to me.

edited Jan 20 '21 at 11:19

answered Feb 17 '20 at 19:46

StayOnTarget

11,743
10
52
81

Error: 'Cannot create unknown type '{clr-namespace:NameSpace.Properties}Settings'.'

4 Answers4

Linked

Related