How to use reflection on nested classes in order to get values

Question

I have to an upper class with nested classes

public class Preferences
{
    public FunctionClass function { get; set; } = new FunctionClass();
    public class FunctionClass
    {
        public string programfolder { get; set; } = "";
        ...
    }

    public LoggerClass logger { get; set; } = new LoggerClass();
    public class LoggerClass 
    {
        public string logFolder { get; set; } = "Log";
        ...
    }

    public OptionClass options { get; set; } = new OptionClass();
    public class OptionClass
    {
        public bool showGraphics { get; set; } = true;
        ...
    }

    public MqttSpSetupClass MqttSpSetup { get; set; } = new MqttSpSetupClass();
    public class MqttSpSetupClass
    {
        public string strAddress { get; set; } = "localhost";
        ...
    }
}

so I want reflection to cycle on all member of each inner class

PropertyInfo[] props_Outer = typeof(IoAppPreferences).GetProperties();
int counter = 0;
foreach (PropertyInfo prop_Upper in props_Outer)
{
    var sName_Outer = prop_Upper.Name;
    var val_Outer = props_Outer.GetValue(counter ++);
        
    PropertyInfo[] properties_Inner;
    switch (sName_Outer.ToUpper())
    {
        case "DIMS": properties_Inner = typeof(IoAppPreferences.DimsClass).GetProperties(); break;
     ...    
    }

             
    foreach (PropertyInfo prop_Inner in properties_Inner)
    {
        var sName = prop_Inner.Name;
        //prefs.function

        var sVal = prop_Inner.GetValue(val_Outer);<------ERROR

        switch (prop_Inner.Name.ToUpper())
        {
         ...            
        }
    }

I get an error where I put the arrow. And the reason is that val_Outer is FunctionClass function while if I hardcode prefs.function it is ok. Of course, I can put a switch per each one, but my question is: is there a better way to solve it?

I have seen this solution but can't fit to my needs

Answer 1

You got error because val_Outer is wrong instance. You are trying to get value out of counter integer props_Outer.GetValue(counter ++)

If your goal is to get property values from nested classes you must have instance of Preferences object:

    var appPreferences = new Preferences();
    var propsOuter = appPreferences.GetType().GetProperties();

    foreach (var po in propsOuter)
    {
        var valueOuter = po.GetValue(appPreferences);
        Console.WriteLine($"{po.Name}");

        if (valueOuter == null) continue;

        var propsInner = valueOuter.GetType().GetProperties();
        foreach (var pi in propsInner)
        {
            var valueInner = pi.GetValue(valueOuter);
            Console.WriteLine($"{pi.Name}: {valueInner}");
        }
    }

But getting values through reflection is pretty much useless if you already have object instance.