Inline parameter name hints for C# and VB.NET in ReSharper and Rider

When editing code in the latest builds of ReSharper 2018.3 EAP and Rider 2018.3 EAP,  the inline parameter hints for C# and VB.NET are something you will notice immediately. Let’s see how this new feature makes code more readable, and how we can configure it.

What are inline parameter hints?

When using a literal in a method call, ReSharper and Rider will annotate those with the name of the parameter. This makes it much easier to understand what their value represents.

For example, we can see that the string literal "\\s" here, represents the pattern of a regular expression:

Example of inline parameter hints

When hovering an inline parameter hint in ReSharper, we’ll also display XML documentation when available:

Display XMLDoc on hover

One place where inline parameter hints become very useful, is when passing in null values or booleans. What do the null and false arguments represent here?

var people = peopleService.Find("Maarten", null, false);

The meaning of these becomes clear immediately when using inline parameter hints, without having to rely on using named arguments for readability:

Inline parameter hints for null and boolean values

When are inline parameter hints shown?

Generally speaking, ReSharper and Rider will display inline parameter hints for literals and null values, lambda and array expressions, anonymous methods and object creation expressions, constants and enumeration values.

ReSharper and Rider do not display inline parameter hints for all literals and null values, however. Many base class library (BCL) methods have an obvious name and functionality, and displaying inline parameter hints would not improve readability for these.

For example, in the following cases, the meaning of all parameters becomes clear from looking at their usage:

No parameter hints when obvious or natural

Showing (or not showing) inline parameter hints can be configured in ReSharper’s settings, under Environment | Editor | Parameter Name Hints. Similarly in Rider, we can configure these under Editor | Parameter Name Hints | C# and Visual Basic .NET.

Configuring inline parameter hints

Disable inline parameter hints can be done from the settings as well. A quick way to enable/disable parameter hints is by using the status indicator context menu:

Status indicator context menu

In some cases, it may be useful to disable inline parameter hints for a certain method call. This can be done using the Configure Parameter Name Hints action (Alt+Enter):

Configure Parameter Name Hitns - Hide for specific method

Once applied, the method will be added to the exclude list in the settings:

Do not show parameter hints for method - exclude list

If we want to re-enable parameter hints for the Regex.Split() method, we can drop the entry from this list. We could also expand the entry here, and add additional namespaces and methods where inline parameter hints should be disabled.

Download ReSharper 2018.3 EAP or Rider 2018.3 EAP and give it a try! We’d love to hear your feedback!

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