Sign Up

Sign Up to our social questions and Answers Engine to ask questions, answer people’s questions, and connect with other people.

Have an account? Sign In

Have an account? Sign In Now

Sign In

Login to our social questions & Answers Engine to ask questions answer people’s questions & connect with other people.

Sign Up Here

Forgot Password?

Don't have account, Sign Up Here

Forgot Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

Have an account? Sign In Now

You must login to ask a question.

Forgot Password?

Need An Account, Sign Up Here

Please briefly explain why you feel this question should be reported.

Please briefly explain why you feel this answer should be reported.

Please briefly explain why you feel this user should be reported.

Sign InSign Up

The Archive Base

The Archive Base Logo The Archive Base Logo

The Archive Base Navigation

  • SEARCH
  • Home
  • About Us
  • Blog
  • Contact Us
Search
Ask A Question

Mobile menu

Close
Ask a Question
  • Home
  • Add group
  • Groups page
  • Feed
  • User Profile
  • Communities
  • Questions
    • New Questions
    • Trending Questions
    • Must read Questions
    • Hot Questions
  • Polls
  • Tags
  • Badges
  • Buy Points
  • Users
  • Help
  • Buy Theme
  • SEARCH
Home/ Questions/Q 8088737
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Editorial Team
Asked: June 5, 20262026-06-05T19:10:29+00:00 2026-06-05T19:10:29+00:00

I’ve been researching for a while now trying to find a reason why the

  • 0

I’ve been researching for a while now trying to find a reason why the following would be occuring, but no solutions on StackOverflow or Google are able to help me.

I have a custom UserControl that is attempting to reference a namespace within the same project:

xmlns:my="clr-namespace:ColorPicker"

however when I compile I get the following error:

Undefined CLR namespace. The ‘clr-namespace’ URI refers to a namespace ‘ColorPicker’ that is not included in the assembly.

This is resulting in not being able to build my project or reference other custom controls within the xaml, generating these kinds of errors:

The type ‘my:ColorSelector’ was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built.

I’ve attempted all the solutions given in these posts:

adding a custom namespace to xaml

WPF xmlns: The 'clr-namespace' URI refers to a namespace that is not included in the assembly

The 'clr-namespace' URI refers to a namespace that is not included in the assembly

Undefined CLR namespace

Also, just to be clear, I’m not getting any other errors about other files in this project, so it doesn’t seem like it could be the result of other files not compiling.

UPDATE: A sample project that produces the error for me can be downloaded here: http://www.filefactory.com/file/28fbmhj3f4qj/n/ColorPicker_zip

  • 1 1 Answer
  • 0 Views
  • 0 Followers
  • 0
Share
  • Facebook
  • Report

Leave an answer
Cancel reply

You must login to add an answer.

Forgot Password?

Need An Account, Sign Up Here

1 Answer

  • Voted
  • Oldest
  • Recent
  • Random
  1. Editorial Team
    Editorial Team
    2026-06-05T19:10:30+00:00Added an answer on June 5, 2026 at 7:10 pm

    Your first linked question has the answer. The answer is: you have to build the assembly containing the namespace and referenced classes/controls before you can reference it in .xaml. I commented out your xaml namespace declarations, then commented out the xaml elements from those namespaces, then commented out the C# code that broke as a result of those elements no longer being declared. In other words, I kept commenting till I could build successfully. Once the assembly built, I uncommented the xaml namespace declarations, then the elements. This gave an error about needing to use x:Name instead of Name on those elements, so I did so. Then uncommented the C# code and it builds.

    • 0
    • Reply
    • Share
      Share
      • Share on Facebook
      • Share on Twitter
      • Share on LinkedIn
      • Share on WhatsApp
      • Report

Sidebar

Related Questions

I have a jquery bug and I've been looking for hours now, I can't
Seemingly simple, but I cannot find anything relevant on the web. What is the
link Im having trouble converting the html entites into html characters, (&# 8217;) i
I want to count how many characters a certain string has in PHP, but
I would like to count the length of a string with PHP. The string
For some reason, after submitting a string like this Jack’s Spindle from a text
I am trying to understand how to use SyndicationItem to display feed which is
Basically, what I'm trying to create is a page of div tags, each has
I have a string like this: La Torre Eiffel paragonata all’Everest What PHP function
this is what i have right now Drawing an RSS feed into the php,

Explore

  • Home
  • Add group
  • Groups page
  • Communities
  • Questions
    • New Questions
    • Trending Questions
    • Must read Questions
    • Hot Questions
  • Polls
  • Tags
  • Badges
  • Users
  • Help
  • SEARCH

Footer

© 2021 The Archive Base. All Rights Reserved
With Love by The Archive Base

Insert/edit link

Enter the destination URL

Or link to existing content

    No search term specified. Showing recent items. Search or use up and down arrow keys to select an item.