c# - Can I get parameter names/values procedurally from the currently executing function?

Question

I would like to do something like this:

public MyFunction(int integerParameter, string stringParameter){
    //Do this:
    LogParameters();
    //Instead of this:
    //Log.Debug("integerParameter: " + integerParameter + 
    //          ", stringParameter: " + stringParameter);

}

public LogParameters(){
    //Look up 1 level in the call stack (if possible),
    //Programmatically loop through the function's parameters/values
    //and log them to a file (with the function name as well).
    //If I can pass a MethodInfo instead of analyzing the call stack, great.
}

I'm not even sure what I want to do is possible, but it would be very nice to be able to automatically output parameter names/values at runtime to a file without explicitly writing the code to log them.

Is it possible?

question from:https://stackoverflow.com/questions/2405230/can-i-get-parameter-names-values-procedurally-from-the-currently-executing-funct

Answer 1

I realize people linked to other questions which mentioned PostSharp, but I couldn't help posting the code that solved my problem (using PostSharp) so other people could benefit from it.

class Program {
    static void Main(string[] args) {
        Trace.Listeners.Add(new TextWriterTraceListener(Console.Out));
        new MyClass().MyMethod(44, "asdf qwer 1234", 3.14f, true);
        Console.ReadKey();
    }
}
public class MyClass {
    public MyClass() {
    }
    [Trace("Debug")]
    public int MyMethod(int x, string someString, float anotherFloat, bool theBool) {
        return x + 1;
    }
}
[Serializable]
public sealed class TraceAttribute : OnMethodBoundaryAspect {
    private readonly string category;

    public TraceAttribute(string category) {
        this.category = category;
    }

    public string Category { get { return category; } }

    public override void OnEntry(MethodExecutionArgs args) {
        Trace.WriteLine(string.Format("Entering {0}.{1}.", 
                                      args.Method.DeclaringType.Name, 
                                      args.Method.Name), category);

        for (int x = 0; x < args.Arguments.Count; x++) {
            Trace.WriteLine(args.Method.GetParameters()[x].Name + " = " + 
                            args.Arguments.GetArgument(x));
        }
    }

    public override void OnExit(MethodExecutionArgs args) {
        Trace.WriteLine("Return Value: " + args.ReturnValue);

        Trace.WriteLine(string.Format("Leaving {0}.{1}.", 
                                      args.Method.DeclaringType.Name, 
                                      args.Method.Name), category);
    }
} 

Simply adding the Trace attribute to a method will cause very nice debugging information to be output, like so:

Debug: Entering MyClass.MyMethod. 
x = 44
someString = asdf qwer 1234
anotherFloat = 3.14
theBool = True
Return Value: 45
Debug: Leaving MyClass.MyMethod.