ReSharper 2021.3 Help

Import missing namespaces

When you use types whose namespaces have not been imported in the file, ReSharper helps you locate these types and add the missing namespace import directives. If there are several missing namespaces for an unresolved type, for example, after you paste a block of code in the file, ReSharper would help you import all these namespaces in a single action.

ReSharper looks for non-imported namespaces in the following assemblies: assemblies referenced in the current project, assemblies referenced in other projects in the solution, assemblies that are referenced transitively. If the type is found in a module that is not referenced in the current project, ReSharper also suggests adding a reference to this module.

The missing namespaces are imported according to your namespace import preferences (for example, import directives are inserted or type names qualifiers are added).

The import directives are added in a fixed order: all System.* namespaces go first, sorted alphabetically by the second word after the dot; all other namespaces go next, in alphabetical order.

When you edit a code file, types with missing namespaces are detected with the design-time code inspection (so make sure that it is enabled) and highlighted as errors. By default, the action that imports missing namespaces differs from the normal quick-fix: it is displayed as a popup that hovers either over the first unresolved symbol regardless of your caret position:

ReSharper: Namespace import quick-fix

or after a pasted code bock:

ReSharper: Namespace import fix for pasted code block

Thus, you can apply this fix for all unresolved types with the habitual Alt+Enter shortcut without changing your current caret position, so your editing session is not interrupted. Note that the Import types for pasted code action only appears if all non-imported types in the pasted code block can be unambiguously found in the referenced modules of the current project.

In case several namespace contain the unresolved symbol, ReSharper lets you choose the namespace to import:

ReSharper: choosing a namespace to import

If you chose not to import a required namespace when the popup was displayed, or if you disabled Show the 'Import missing references' popup in editor on the Code Editing | Type Import page of ReSharper options (Alt+R, O), you can import a type at any time by setting the caret at the type, pressing Alt+Enter and choosing the corresponding quick-fix.

ReSharper: quick-fixes for missing namespace import

To quickly choose whether to show import suggestions via the popup, or an entry in the Alt+Enter menu, use the context menu of the file status indicator:

ReSharper: Choosing import popup mode from the context menu of the file status indicator

You may want some namespaces not to be suggested, for example, if you have something similar to a system type in your solution, say MyFramework.MyCollections.List, but you are not actually using it. To exclude such items from the suggestions, add them to the Exclude from import and completion list on the Code Editing | Type Import page of ReSharper options (Alt+R, O).

The format of the entries is Fully.Qualified.Name, Fully.Qualified.Name.Prefix*, or *Fully.Qualified.Name.Suffix. Generic types are specified as List`1.

This feature is supported in the following languages and technologies:

Language: C#

Language: VB.NET

Language: C++

Language: HTML

Language: ASP.NET

Language: Razor

Language: JavaScript

Language: TypeScript

Language: CSS

Language: XML

Language: XAML

Language: Resx

Language: Build Scripts

Language: Protobuf

Language: JSON

Feature is available in C#

Feature is available in Visual Basic .NET

Feature is not available in C++

Feature is not available in HTML

Feature is available in ASP.NET

Feature is available in Razor

Feature is not available in JavaScript

Feature is available in TypeScript

Feature is not available in CSS

Feature is not available in XML

Feature is not available in XAML

Feature is not available in Resource files

Feature is not available in build script files

Feature is not available in Protobuf

Feature is not available in JSON

The instructions and examples given here address the use of the feature in C#. For details specific to other languages, see corresponding topics in the ReSharper by language section.

Last modified: 07 April 2022