How to extract an object name

Question

i've got a class filled with lists of subclasses:

public class ClassOfKb
{
    public List<Data> KbDatas {get;set;}
    public List<Product> KbProducts {get;set}
}

public class Data
{
    public Guid ID {get;set;}
    public byte[] data {get;set;}
    public string Name {get;set;}
}
public class Product
{
    public Guid ID {get;set;}
    public string Name {get;set;}
    public byte[] Image {get;set;}
}

i create an object:

ClassOfKb kb = new ClassOfKb

now i'd like to extract the string "Datas" from the sub-object kb.KbDatas, I tried:

string name = kb.KbDatas.GetType().BaseType.Name.Substring(2);

aswell as:

string name = kb.KbDatas.GetType().Name.Substring(2);

but nothing gave me what I need, is there any way to do this?

EDIT: to specify my question, the string I need is the name of the list, except the first two letters! KbDatas => Datas

EDIT2: i did a mistake, the list-names and class-names are different and i need the list-name

Answer 1

You can use Type.GetGenericArguments to solve this

       ClassOfKb kb=new ClassOfKb();
      kb.KbData = new List<Data>();
      string nameOfData = Type.GetType(kb.KbData.ToString()).GetGenericArguments().Single().Name;

OUTPUT : nameOfData = Data

      kb.KbProduct = new List<Product>();
      string nameOfProduct = Type.GetType(kb.KbProduct.ToString()).GetGenericArguments().Single().Name;

OUTPUT : nameOfProduct = Product

Answer 2

Since that's a collection it is likely that there are multiple Data objects in it, each with a name. You can use String.Join to concat them with a separator:

string names = string.Join(",", kb.KbData.Select(d => d.Name));

If there's just one object you don't get a comma at the end. If there's no object you get an empty string.

Answer 3

erm, since you have a List of Data there will be a sequence of Names.

IEnumerable<string> names = kb.KbData.Select(d => d.Name);

maybe you want just the first one?

string firstName = kb.KbData.First(d => d.Name);

Answer 4

Try this one

string name = kb.KbData[0].Name.Substring(2);

Answer 5

From the sounds of what you've written, you're looking to get the name of the type in the List instance KbData?

If so, I think this may be what you're looking for: https://stackoverflow.com/a/1043778/775479

Answer 6

If you are trying to get the name of the property. There are several methods for doing so.

Get the name of the generic argument from the property itself - If you know the name of the property.

ClassOfKb kb = new ClassOfKb()
   { KbData = new List<Data>(), KbProduct = new List<Product>() };
Console.WriteLine(kb.KbData.GetType().GetGenericArguments()[0].Name);

Get the name of the property from reflection, if you know the data type of the property.

System.Reflection.PropertyInfo pi = kb.GetType()
           .GetProperties()
           .FirstOrDefault(p=>p.PropertyType == typeof(List<Data>));
Console.WriteLine(pi.Name.Substring(2)); // ignoring the kb prefix

Answer 7

You can achieve this with reflection. This is example without any checks - just show the mechanism:

PropertyInfo propertyInfo = typeof(ClassOfKb).GetProperty("KbData");
Type propertyType = propertyInfo.PropertyType;
Type genericArgument = propertyType.GenericTypeArguments[0];
string name = genericArgument.Name;

Because property KbData is generic List<Data> you need ask for generic arguments of property type: propertyType.GenericTypeArguments[0] and you should test if the type is really generic by genericArgument.IsGenericType and check generic arguments count

Answer 8

If you need the property name than you can use Expression. The code below define function for extract name prom a property:

public string GetPropertyName<T>(Expression<Func<T>> property)
{
    return ((MemberExpression)property.Body).Member.Name;
}

This converts property to property name string:

GetPropertyName(()=>k.KbDatas).Substring(2)