Get derived type class

Question

So, I have the following structure:

public abstract class MyBase
{
    public Type TargetType { get; protected set; }
}

public class A : MyBase
{
    public A()
    {
        TargetType = GetType();//Wrong, I need B class type not C
    }
}

public class B : A
{
    public B() { }
}

public class C : B
{
    public C() { }
}

Of course, I can receive my type in this way:

public class B : A
{
    public B()
    {
        TargetType = typeof(B);
    }
}

Actually, I have to write some code to make the example clearer:

Class1.cs

public static Dictionary<Type, Type> MyTypes = new Dictionary<Type, Type>()
{
    { typeof(B),typeof(BView) }
}

public Class1()
{
    C itemC = new C();
    Class2.Initialize(itemC);
}

Class2.cs

public static Initialize(MyBase myBase)
{
    Type t;
    Class1.MyTypes.TryGetValue(myBase.TargetType, out t);
    //I need get BView but I get null because *myBase.TargetType* is C class type
}

Level structure:

Level 0:(MyBase) - 1 object
Level 1:(A) - 2 objects
Level 2:(B) - 100 objects and more
Level 3:(C) - 80 objects and more

I gave this case in brackets

I will be grateful for any help

Can you please explain what you are trying to achieve? Your example isn't clear at all. — Federico Dipuma, Apr 22 '18 at 19:58
I inherited after A about 100 different objects. So I need find derived type in A class (In this case B class) — Mr Luk, Apr 22 '18 at 20:06
System.Type has a 'BaseType'-Property, have you tried that ? You can call GetType().BaseType in a C-Instance and this should return B-Type — D.J., Apr 22 '18 at 20:09
I thought about it but I inherited after B about 80 different objects, so this way is bad too — Mr Luk, Apr 22 '18 at 20:15
Btw, I inherited after abstract class only 2 different objects. — Mr Luk, Apr 22 '18 at 20:20
Why not simply add another entry to the dictionary? I.e. `{ typeof(C),typeof(BView) }`. Or, alternatively, change the dictionary handling so that it checks `if(myObj is B)` instead of `if(typeof(myObj) == typeof(B)`? (this is pseudocode to explain the difference) — Flater, Apr 23 '18 at 05:42
Because it will be a one-to-many relationship and I need one to one. The second part of the sentence: I can not check, because I have over 100 objects (B, B1, B2, B3 ...) and all have to have link — Mr Luk, Apr 23 '18 at 12:38

score 4 · Answer 1 · answered Apr 22 '18 at 19:56

4

On any instance of an object you can call .GetType() to get the type of that object.

You don't need to set the type on construction

answered Apr 22 '18 at 19:56

BlythMeister

299
1
12

score 2 · Answer 2 · answered Apr 22 '18 at 20:17

I didn't understand completely your question, but these are some possibilities to get informations about a type:

var a = new A();
Console.WriteLine(a.GetType().Name); // Output: A
Console.WriteLine(a.GetType().BaseType?.Name); // Output: MyBase

var b = new B();
Console.WriteLine(b.GetType().Name); // Output: B
Console.WriteLine(b.GetType().BaseType?.Name); // Output: A

// A simple loop to get to visit the derivance chain
var currentType = b.GetType();
while (currentType != typeof(object))
{
    Console.WriteLine(currentType.Name);
    currentType = currentType.BaseType;
}
// Output: B A MyBase

Also, I suggest to read this post about the difference between GetType and typeof

Hope this helps.

To extend your answer to what I think is the core of OP's question, notice that `B b = new B()` and `A b = new B()` will yield the same output as is listed for `var b = new B()` in this answer. — Flater, Apr 23 '18 at 05:38

Get derived type class

2 Answers2