Code style and cleanup
Syntax styles
Bodies of Type Members

Code syntax style: bodies of type members

Last modified: 21 July 2022

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Expression-bodied members is a C# 6.0 feature.
By default, ReSharper automatically detects C# version based on the associated compiler. However, you can specify the target C# version explicitly for a project — right-click the project in the Solution Explorer, choose Edit project item properties from the context menu and use the C# Language Level selector .
To set the C# version for all projects in your solution, specify it in a Directory.Build.props file in your solution directory as described here.

Starting from C# 6.0, you can declare type members using expression bodies, which look very similar to lambda expressions. You can use expression-bodied methods and properties to further simplify the syntax of simple implementations.

If you prefer to stick to either expression-bodied or block-bodied implementations for simple members, ReSharper lets you configure your preferences separately for different kinds of members and maintain the consistency of your preferences throughout your codebase.

ReSharper helps you enforce preferences for expression-bodied members in the existing code and takes your preferences into account when it produces new code with code completion and code generation features, applies code templates and performs refactorings.

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Expression-bodied and block-bodied implementations compile to the same IL, so there is no difference in performance between them.

Enforce preferences for expression-bodied functions

ReSharper can help you check all simple members for compliance with your preferences and if they do not comply, it highlights such implementations and suggests the corresponding quick-fix or fix in scope. Default ReSharper's preferences say that expression body is preferred for properties, indexers, and events:

ReSharper. 'To expression body' quick-fix

For all other kinds of members, suggestions are disabled by default. However, you can configure your preferences in a different way, so that, for example, ReSharper suggests converting expression-bodied methods to block bodies:

ReSharper. 'To statement body' quick-fix

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Preferences for expression-bodied functions are not applied to generated code. By default, ReSharper provides the list of file masks and regions for generated code typically produced by Visual Studio (for example, Windows Form Designer-generated code). If necessary, you can edit the list of generated items on the Code Inspection | Generated Code page of ReSharper options (Alt+R, O).

Another option to enforce preferences for expression-bodied members in a bulk mode is code cleanup. You can either run code cleanup with one of the built-in profiles Full Cleanup or Reformat & Apply Syntax Style, or create and run a custom profile solely targeted at your specific task as described below.

Apply preferences for expression-bodied functions with custom Code Cleanup profile

Select ReSharper | Options from the main menu or press Alt+R O.
Go to the cleanup profiles settings page: Code Editing | Code Cleanup | Profiles.
Create a new profile as described in the Create a new custom cleanup profile section. In the Selected profile settings section for the new profile, tick the Apply code body style (expression body vs. block body) checkbox. Optionally, you can enable other code cleanup tasks in this profile.
Click Save in the Options dialog 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 list. For more information, see manage and share resharper settings.
Select the scope where you want to enforce your preferences:
- Set the caret anywhere in the file to enforce your preferences to the file.
- Select one or more items in the Solution Explorer to enforce your preferences in the files under these nodes and their child items.
Do one of the following:
- Press Ctrl+E C 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.
In the Code Cleanup dialog that opens, select the newly created profile .
Click Run. ReSharper will enforce your preferences in the selected scope.

If you want to enforce preferences for expression-bodied members without opening the Code Cleanup dialog to choose a profile, you can bind the created profile to the silent cleanup and run it by pressing Ctrl+E F. You can also create a custom cleanup profile that would combine applying the preferences with other code style tasks.

To apply preferences for expression-bodied functions together with all other formatting and syntax style rules to the selected code block, Alt+Enter and choose Reformat and cleanup | Reformat & apply syntax style.

You can enforce preferences for expression-bodied members every time you save changes in a file to make sure that your edits always comply with your code style.

Automatically enforce preferences for expression-bodied members on saving changes

Select ReSharper | Options from the main menu or press Alt+R O.
Go to the cleanup profiles settings page: Code Editing | Code Cleanup | Profiles.
Select your custom Code Cleanup profile and click Set as default (the default profile is also used for silent cleanup).
Go to the Code Editing | Code Cleanup | General options page and select Automatically run cleanup when saving a file.
Optionally, you can restrict automatic cleanup to specific files by a file mask. You can also select Only changed parts of file to make sure that cleanup is applied to the code affected by your changes, and the rest of the code in the file is not modified.
Click Save in the dialog 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 list. For more information, see manage and share resharper settings.
The next time you finish editing and save the file (Ctrl+S) or all files (Ctrl+Shift+S), ReSharper will clean up the affected files using the selected profile. If the default cleanup profile is not selected, ReSharper will prompt you choose one of the profiles.

Configure preferences for expression-bodied functions

Your function body preferences are saved using the mechanism of layer-based settings. Among other things, this mechanism allows you to maintain different preferences for different solutions as well as to keep these preferences under a VCS and automatically share them with your team members.

Configure expression body style in options

Go to the Code Editing | C# | Syntax Style page of ReSharper options (Alt+R, O).
Modify settings in the Code body category according to your coding practices/standards.
By default, ReSharper applies heuristics to decide whether to convert block bodies of methods to expression bodies. Among other things, this means that ReSharper will not suggest expression bodies for void methods and for methods that contain a lambda expression.
You can simplify this logic by clearing the Apply style heuristics checkbox. In this case, the logic is simple: if you choose to use expression body for some kind of members, ReSharper will suggest expression body if the declaration of a member of this kind consists of a single statement.
The Notify with selectors in the right column allow you to set severity levels of code inspections detecting code that differs from your preferences.
Click Save in the Options dialog 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 list. For more information, see manage and share resharper settings.

You can also change your preferences for function bodies right in the editor, where a corresponding issue is highlighted:

Change preference of using expression body from the editor

Set the caret to a code issue highlighted by a ReSharper's inspection.
Press Alt+Enter or click the action indicator to the left of the caret to open the action list.
In the action list, choose Inspection "Use preferred body style..." | Configure code style and then select a desired preference:
Your change will be saved using the smart save logic.
If you need to save the modified style preference in a shared settings layer, click the Configure code style menu item or press Enter when it is selected. ReSharper will open the Code Editing | C# | Syntax Style page of ReSharper options where you can modify your preference as needed, click Save To and then choose the desired settings layer.

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Code style features that only change whitespaces, tabs, and line breaks are configurable in formatting preferences.

This feature is supported in the following languages and technologies:

Code syntax style: bodies of type members﻿

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tip

Enforce preferences for expression-bodied functions﻿

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Apply preferences for expression-bodied functions with custom Code Cleanup profile﻿

Automatically enforce preferences for expression-bodied members on saving changes﻿

Configure preferences for expression-bodied functions﻿

Configure expression body style in options﻿

Change preference of using expression body from the editor﻿

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