C# – Hide a method from the stack trace

When you want to exclude a method from showing up in the stack trace, you can apply the StackTraceHidden attribute to the method:

[System.Diagnostics.StackTraceHidden]
public static void Throw() 
{
	//check conditions and throw
}
Code language: C# (cs)

Note: This attribute was added in .NET 6.

You can apply StackTraceHidden to a class to hide all of its methods from the stack trace:

[System.Diagnostics.StackTraceHidden]
public static class Helpers
{
	//lots of exception thrower helper methods
}
Code language: C# (cs)

Use StackTraceHidden with throw helper methods

StackTraceHidden is very useful for hiding throw helper methods. Devs often use these methods to get rid of redundant if-then-throw statements. The problem is these methods pollute the stack trace. Here’s an example of what the stack trace looks like when you call ArgumentNullException.ThrowIfNull():

 System.ArgumentNullException: Value cannot be null. (Parameter 'employee.FirstName')
   at System.ArgumentNullException.Throw(String paramName)
   at System.ArgumentNullException.ThrowIfNull(Object argument, String paramName)
   at Program.Process(Employee employee) in D:\Program.cs:line 19
Code language: plaintext (plaintext)

You can use the StackTraceHidden attribute to eliminate the throw helper methods from the stack trace. Here’s an example of writing a method that’s equivalent to ArgumentNullException.ThrowIfNull() except it’s hidden from the stack trace:

using System.Runtime.CompilerServices;
using System.Diagnostics.CodeAnalysis;

[System.Diagnostics.StackTraceHidden]
public static class Helpers
{
	public static void ThrowIfNull([NotNull] object? argument, 
		[CallerArgumentExpression("argument")] string paramName = null)
	{
		if (argument == null)
		{
			throw new ArgumentNullException(paramName);
		}
	}
}
Code language: C# (cs)

Note: It’s also using the CallerArgumentExpression attribute to automatically get the argument names.

Here’s the stack trace now. Notice it doesn’t have the Helpers.ThrowIfNull() call in it:

System.ArgumentNullException: Value cannot be null. (Parameter 'employee.FirstName')
   at Program.Process(Employee employee) in D:\Program.cs:line 19Code language: plaintext (plaintext)