Debugging in X++ with DebuggerDisplayAttribute

When debugging in Microsoft Dynamics 365 Finance & Operations (F&O), examining objects in the debugger can sometimes be overwhelming. By default, the debugger shows the full object type, which might not be the most informative representation. Fortunately, we can use the DebuggerDisplayAttribute to customize how an object is displayed during debugging.

What is DebuggerDisplayAttribute?

DebuggerDisplayAttribute is a .NET attribute that allows developers to define a more meaningful string representation for objects when viewed in a debugger. While it’s commonly used in C#, it can also be leveraged in X++ classes that extend .NET objects.

Example in X++

Consider the following example of a class implementing the DebuggerDisplayAttribute:

[System.Diagnostics.DebuggerDisplayAttribute("{toString()}")]
public final class DebuggerDisplayTest_BEC
{
    public str toString()
    {
        return 'Hello World!';
    }
}

How It Works

1. The [System.Diagnostics.DebuggerDisplayAttribute("{toString()}")] line instructs the debugger to display the result of toString() when an instance of DebuggerDisplayTest_BEC is inspected.
2. The toString() method provides a human-readable string representation of the expression, making debugging much more intuitive.
3. When debugging, instead of seeing just the class name, you’ll see an output like Hello World! in this example, making it clear what the object represents.

Why Use DebuggerDisplayAttribute?

• Improved Readability: Helps in quickly identifying objects and their state.
• Faster Debugging: Reduces the need to expand object properties to understand their values.
• Better Maintenance: Makes debugging more efficient for teams working with complex object hierarchies.

Final Thoughts

The DebuggerDisplayAttribute is a small but powerful feature that can greatly enhance your debugging experience in X++. If you work with complex object structures, this attribute allows you to see meaningful information at a glance, making troubleshooting and development smoother.

Have you used DebuggerDisplayAttribute in your X++ development? Let us know in the comments!