Published on

DebuggerDisplay in C#: Simplifying Debugging with Customized Display

Overview

When it comes to debugging code, developers often find themselves sifting through lengthy objects and collections, struggling to extract the necessary information. This process can be time-consuming and frustrating, especially when dealing with complex data structures. However, C# offers a handy tool called DebuggerDisplay that allows developers to customize how objects are displayed in the debugger, making the debugging experience much more efficient and enjoyable.

What is DebuggerDisplay?

DebuggerDisplay is an attribute in C# that enables developers to define a custom display format for classes or structs during debugging. By applying this attribute to a class or struct, you can control what information is displayed when inspecting objects in the debugger. The custom display format can include property values, field values, or even calculated values that are useful for debugging purposes.

How to Use DebuggerDisplay

Using DebuggerDisplay is straightforward. You need to apply the attribute to a class or struct and provide a string argument that represents the custom display format. The string argument can contain placeholders enclosed in braces {} that are replaced with the corresponding values during debugging.

Let's consider an example. Suppose we have a Person class with properties for Name, Age, and Email. To customize the display of the Person objects during debugging, we can apply the DebuggerDisplay attribute as follows:

using System.Diagnostics;

[DebuggerDisplay("Name: {Name}, Age: {Age}, Email: {Email}")]
public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public string Email { get; set; }
}

In the above code, we've specified the custom display format as "Name: {Name}, Age: {Age}, Email: {Email}". Now, when we examine a Person object in the debugger, it will display the values of the Name, Age, and Email properties instead of the default object information.

Formatting Options

The string argument within DebuggerDisplay can utilize various formatting options to provide more flexibility in the displayed information. Here are a few commonly used formatting options:

  • Property Accessors: You can use the get accessor to display the value of a property or field. For example, {Name} will display the value of the Name property.
  • String Formatting: The format specifiers used in string.Format() can be employed within DebuggerDisplay. For instance, {Age:D2} will display the Age property as a two-digit decimal number.
  • Expressions: You can include simple expressions involving properties or fields. For example, {Name.ToUpper()} will display the Name property in uppercase letters.

Nested Objects and Collections

DebuggerDisplay can handle complex scenarios involving nested objects and collections. Suppose we have a Team class that contains a collection of Person objects. We want to display the team name along with a summary of the team members during debugging. Here's how we can achieve this:

using System.Collections.Generic;
using System.Diagnostics;

[DebuggerDisplay("Team: {Name}, Members: {GetMemberSummary()}")]
public class Team
{
    public string Name { get; set; }
    public List<Person> Members { get; set; }

    private string GetMemberSummary()
    {
        return $"{Members.Count} members";
    }
}

In this example, we're using the GetMemberSummary() method to calculate the summary of team members. By including {GetMemberSummary()} in the DebuggerDisplay attribute, the debugger will display the team name and the member summary when inspecting a

Team object.

Conditional Display

Sometimes, you may want to display additional information based on certain conditions. DebuggerDisplay allows you to incorporate conditional logic using the ? and : operators. Let's modify our Person class example to display the age in brackets only if it's greater than 18:

using System.Diagnostics;

[DebuggerDisplay("Name: {Name}, Age: {Age > 18 ? Age.ToString() : string.Empty}, Email: {Email}")]
public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
    public string Email { get; set; }
}

In this updated example, the Age property is displayed within brackets if its value exceeds 18. Otherwise, an empty string is displayed.

Conclusion

The DebuggerDisplay attribute in C# provides developers with a powerful tool for customizing how objects are displayed during debugging. By specifying a custom display format, including property values, field values, and even calculated values, developers can streamline the debugging process and gain more insights into their code. With its simplicity and flexibility, DebuggerDisplay is an invaluable asset for C# developers seeking to enhance their debugging experience.

So, next time you find yourself grappling with complex objects while debugging, remember to leverage the DebuggerDisplay attribute to simplify your debugging efforts and save valuable time.