ReSharper 2018.1 Help

Making Fields Readonly

It is often reasonable to use the 'readonly' modifier for fields that are assigned in the declaration or in a constructor and only have read usages. By default, ReSharper suggests that you make a field readonly if the above conditions are met. It highlights such fields and suggests the corresponding quick-fix or fix in scope:

Make field readonly quick-fix

If you do not want ReSharper to suggest this, you can disable the code inspection that detects it (Field can be made readonly).

The reverse functionality is also available. If you decide to change a readonly field later in your code (which leads to a compiler error), ReSharper detects the error and suggests fixing it by removing the 'readonly' keyword from the field:

Make non-readonly fix

Another option to make fields readonly in a bulk mode is code cleanup. You can either run code cleanup with the default profile Default: Full Cleanup or run the cleanup with a custom profile solely targeted at your specific task as described below.

To add the 'readonly' keyword to fields that only have read access

  1. Select ReSharper | Options in the main menu.
  2. Go to the Code Cleanup settings page: Code Editing | Code Cleanup.
  3. Create a new profile as described in the To create a new custom cleanup profile section. In the Selected profile settings section for the new profile, tick the Make field read-only, if possible check box. Optionally, you can enable other code cleanup tasks in this profile.
  4. Click Save to apply the modifications and let ReSharper choose where to save them, or save the modifications to a specific settings layer using the Save To drop-down list. For more information, see managing and sharing resharper settings.
  5. Select the scope where you want to make fields readonly:
    • Set the caret anywhere in the file to make fields readonly to the file.
    • Select one or more items in the Solution Explorer to make fields readonly in the files under these nodes and their child items.
  6. Do one of the following:
    • Press Ctrl+Alt+F or choose ReSharper | Edit | Cleanup Code from the main menu.
    • Right-click anywhere in the text editor or right-click the selection and choose Cleanup Code in the context menu.
  7. In the Code Cleanup dialog that opens, select the newly created profile.
  8. Click Run. ReSharper will make fields readonly in the selected scope.

If you want to make fields readonly without opening the Code Cleanup dialog, you can bind the created profile to the silent cleanup and run it simply by pressing Ctrl+Shift+Alt+F. You can also create a custom cleanup profile that would combine making fields readonly with other code style tasks.

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 Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available Feature is not available
Last modified: 20 August 2018

See Also