在类中获取类的属性的值

Question

Ok so I have been up and down the internet looking for a solution to this question. I think my title is maybe no to informative so some background.

I have the following classes:

public class foo { public string Name { get; set; } }
public class foo1 { public string Name { get; set; } }
public class foo2 { public string Name { get; set; } }
public class foo3 { public string Name { get; set; } }
public class foo4 { public string Name { get; set; } }
public class foo5 { public string Name { get; set; } }

public class goo 
{ 
   public string Desc { get; set; }
   public foo f { get; set; }
   public foo1 f1 { get; set; }
   public foo2 f2 { get; set; }
   public foo3 f3 { get; set; }
   public foo4 f4 { get; set; }
}

So now my question, Using Reflection, how can I get to the value of foo.Name when only having a reference to goo.

The normal Reflection code is:

goo g = new goo();
PropertyInfo pInfo = g.GetType().GetProperty("Name");
string Name = (string)pInfo.GetValue(g, null);

So the above code is how you get a property from the goo class. But now how do you get the value of foo.Desc?

I tried the following which doesn't work:

goo g = new goo();
PropertyInfo pInfo = g.GetType().GetProperty("f");
PropertyInfo pInfo2 = pInfo.PropertyType.GetProperty("Desc");
string Name = (string)pInfo2.GetValue(pInfo.PropertyType, null);

Unfortunately I get a Mismatched object error which I can understand because I am trying to use the property type and not the actual instance of the foo class. I also tried to fins a way to instantiate an object from the propertyinfo but if there is a way then it eludes me. I could do something like this:

goo g = new goo();
PropertyInfo propInfo = g.GetType().GetProperty("f");
object tmp;

propInfo.SetValue(g, Convert.ChangeType(new foo(), propInfo.PropertyType), null);
tmp = g.f;

This works but besides having to hard code the class, that is creating a new instance and therefore of now use to me.

As I say I have been up and down looking for a solution. Everything I have found is basically variants on the "get a value of a property of a class" theme but nothing about going another level deeper.

Can anyone help? Is this even possible because I would really like to stay away from hard coding.

EDIT: I have edited the class to more accurately represent what I am working with. Based on the comments below, I am getting the names of the foo instances from a database and that is why I am using Reflection or want to use Reflection instead of hard coding 30+ switch statements.

EDIT: Also I don't know before runtime which foo classes will be populated with data. Also each foo class is different. Unlike my example where each foo class has a string property, in my project each class has a different design which mirrors the database.

EDIT: So Ulugbek Umirov gave the answer. I just didn't see it immediately. Below my implementation so as to maybe help others in the future.

foreach (PropertyInfo pInfo in _standard.GetType().GetProperties())
{
    if (_fullDataModel.ClassDefinitions.Contains(pInfo.Name))
    {
        PropertyInfo _std_pinfo = _standard.GetType().GetProperty(pInfo.Name);
        object g = _std_pinfo.GetValue(_standard, null);

        PropertyInfo props = g.GetType().GetProperty("showMe");
        bool showMe = (bool)props.GetValue(g, null);

        if (showMe)
        {
            string tblName = _fullDataModel.ClassDefinitions[pInfo.Name].                   PropertyGroupDefinitions.Where(p => p.TransactionsTable != true).First().Token;

            //  Use tblName to build up a dataset
        }
    }
}

This does exactly what I wanted. Thank you.

Answer 1

Given your current code you can do the following:

goo g = new goo();
g.f = new foo { Name = "Hello" };

PropertyInfo pInfo = g.GetType().GetProperty("f");
object f = pInfo.GetValue(g);
PropertyInfo pInfo2 = f.GetType().GetProperty("Name");
string name = (string)pInfo2.GetValue(f);

You can set arbitrary property as well:

goo g = new goo();

PropertyInfo pInfo = g.GetType().GetProperty("f");
object f = Activator.CreateInstance(pInfo.PropertyType);
PropertyInfo pInfo2 = f.GetType().GetProperty("Name");
pInfo2.SetValue(f, "Hello");
pInfo.SetValue(g, f);