This extension helps organize C# using statements and is meant to replicate the sorting and cleanup behavior you may be familiar with from Visual Studio. It is an actively-supported, forked version of the abandoned CSharpFormatUsings extension that offers bug fixes, new features, and compatibility with the OmniSharp, Roslyn, and C# Dev Kit Language Servers.
Features
Removes unnecessary using directives (enabled by default but can be disabled) and duplicates.
Sorts using directives in alphabetical order and into groups by the first level of the namespace.
Can be triggered on save, via the right-click menu in the editor, or with the Organize C# Usings command in the Command Palette (can also be setup as a keyboard shortcut).
Inserts a configurable number of empty lines between sets of sorted using statements.
Offers multiple configurable settings for formatting the using section (see "Extension Settings" below).
Version History
1.1.0: Basic support for preprocessing directives in using blocks (Issue #21), reworked the regex that finds blocks of using statements to better handle empty lines and comments, changed the setting for removing unused usings to be a disable-focused one for easier overriding, retire support for the numEmptyLinesAfterUsings & numEmptyLinesBeforeUsings settings, slight refactoring around sorting and splitting. This is our first "pre-release" release, using the numbering scheme suggested by Microsoft ("so, we recommend that extensions use major.EVEN_NUMBER.patch for release versions and major.ODD_NUMBER.patch for pre-release versions").
1.0.6: Fixed a bug that would prevent all unused usings from being removed on the first execution of the "Organize C# Usings" command. The line numbers returned by vs.languages.getDiagnostics were being misinterpreted. New unit tests around the removal of unused usings.
1.0.5: Adds support for running natively on save, improved handling of duplicate removal during cleanup, an output panel channel for debug output, and various improvements in source code.
1.0.4: Handles IDE0005 diagnostics for unused usings from Roslyn, enabling compatibility with the C# extension when OmniSharp is disabled.
1.0.3: Properly handles aliased using directives without breaking syntax such as using [type] [variableName] = whatever. Adds basic unit test coverage.
1.0.2: Fixes editor jumpiness based on Microsoft's recommendation to use TextEditorEdit.delete/insert instead of replace.
1.0.1: Fixed editor jumpiness when running "Organize Usings" on files that require no changes.
1.0.0: Correctly removes unused usings when all of a class's usings are unnecessary, and resolves issues caused by extra blank lines between namespace groups.
Extension Settings
sortOrder: Sets the order of namespaces. Values should be space-separated. "System" by default.
splitGroups: Inserts a blank line between using blocks grouped by the first part of the namespace. Enabled by default.
disableUnusedUsingsRemoval: Disables the removal of unused usings (enabled by default otherwise). Defaults to false.
processUsingsInPreprocessorDirectives: When enabled, unused usings within preprocessing directives will be removed. Defaults to false.
Execution "On Save"
To auto-organize on saving a C# file, add the following to your settings.json file: