1. Double click on the project in the Solution Pad, or right-click on the project and select Options:
2. Choose main settings and you'll be able to edit the default namespace:
3. This value will be automatically set as the root namespace in each new code file you create in your project.

1. Open the project Properties, and then choose the Application panel:
2. This value will be automatically set as the root namespace in each new code file you create in your project.

If you edit the default namespace value in an existing project, it will NOT update existing files, so beware that editing this value will result in two different root namespaces in your project.

Xamarin.Android applications use the Default namespace for the /Resources/Resource.Designer.cs generated file. If the default namespace is changed in an existing project, then existing references to Resource will be broken. The error will read “The name ‘Resource’ does not exist in the current context,” as illustrated by the following screenshot:

Resource.Designer.cs should not be edited directly. To fix these errors either:

• Update the namespace in the affected files to match the new Default namespace, or
• Add a using statement to the affected files, referencing the new Default namespace.