DotNetAspects.Fody 1.0.0

DotNetAspects

A lightweight AOP (Aspect-Oriented Programming) library for .NET 8+, designed as a drop-in replacement for PostSharp's core interception APIs.

Features

• MethodInterceptionAspect: Intercept method calls with full control over execution
• OnMethodBoundaryAspect: Execute code at method boundaries (entry, success, exception, exit)
• LocationInterceptionAspect: Intercept property and field access
• PostSharp-compatible API: Minimal code changes required for migration

Installation

Add a reference to the DotNetAspects project or NuGet package.

Migration from PostSharp

Namespace Changes

Replace PostSharp namespaces with DotNetAspects equivalents:

// Before (PostSharp)
using PostSharp.Aspects;
using PostSharp.Serialization;
using PostSharp.Extensibility;

// After (DotNetAspects)
using DotNetAspects.Interception;
using DotNetAspects.Serialization;
using DotNetAspects.Extensibility;
using DotNetAspects.Args;
using DotNetAspects.Internals;  // For Arguments<T>

Quick Reference

Usage Examples

Method Interception

using DotNetAspects.Interception;
using DotNetAspects.Args;
using DotNetAspects.Serialization;

[PSerializable]
public class LoggingAspect : MethodInterceptionAspect
{
    public override void OnInvoke(MethodInterceptionArgs args)
    {
        Console.WriteLine($"Before: {args.Method.Name}");

        // Execute the original method
        args.Proceed();

        Console.WriteLine($"After: {args.Method.Name}, Result: {args.ReturnValue}");
    }
}

Method Boundary

using DotNetAspects.Interception;
using DotNetAspects.Args;
using DotNetAspects.Serialization;

[PSerializable]
public class TimingAspect : OnMethodBoundaryAspect
{
    public override void OnEntry(MethodExecutionArgs args)
    {
        args.Tag = Stopwatch.StartNew();
    }

    public override void OnExit(MethodExecutionArgs args)
    {
        var sw = (Stopwatch)args.Tag!;
        sw.Stop();
        Console.WriteLine($"{args.Method.Name} took {sw.ElapsedMilliseconds}ms");
    }
}

Property Interception

using DotNetAspects.Interception;
using DotNetAspects.Args;
using DotNetAspects.Serialization;

[PSerializable]
public class NotifyPropertyChangedAspect : LocationInterceptionAspect
{
    public override void OnSetValue(LocationInterceptionArgs args)
    {
        var oldValue = args.GetCurrentValue();
        args.ProceedSetValue();

        if (!Equals(oldValue, args.Value))
        {
            Console.WriteLine($"Property {args.Location.Name} changed");
        }
    }
}

API Reference

MethodInterceptionArgs

MethodExecutionArgs

LocationInterceptionArgs

Project Structure

src/DotNetAspects/
├── Args/
│   ├── IArguments.cs
│   ├── Arguments.cs
│   ├── MethodInterceptionArgs.cs
│   ├── MethodExecutionArgs.cs
│   └── LocationInterceptionArgs.cs
├── Interception/
│   ├── MethodInterceptionAspect.cs
│   ├── OnMethodBoundaryAspect.cs
│   └── LocationInterceptionAspect.cs
├── Serialization/
│   └── PSerializableAttribute.cs
├── Extensibility/
│   ├── MulticastTargets.cs
│   └── MulticastAttributeUsageAttribute.cs
└── Internals/
    └── Arguments.cs (generic versions)

License

MIT License