c# - Can I change a base class object to a derived class object from inside the base class? -

Actually, I want to do something like this:

  public class A {public zero AddData (byte [] data) {// analyze data if (BoolFromAnalyzedData == true) {AFirstType a = new AFSTType (); A.SomeInt = IntFromAnalyzedData; This = a; } Else {ASecondType a = new ASecondType (); A.SomeString = StringForm Analyzed Data; This = a; }}} Public Category AFTERType: A {public int SomeInt; } Public Class Eskkend Type: A {public string Some strings; }   
 Then, I want to be able to:  
  a.AddData (data); If (AAST type) dustf (as an ASFType) .SomeInt); And if (a escond type) dustf ((AS ASKCAND type). Some strings);   
 I have a class and after that there are two separate classes with different properties. When I make the base class, I do not know how it should be, I Only can understand how it is late when I get some data and analyze it. Again, I want to be able to check how it is and use the derived class properties.  
 The problem is, I can not get into  this  C #, so how can I use the option?   
 
 
 I think you should change your attitude towards the problem.  
 Combining your unit (which stores data) with your hydration code (which populates them).  
 You should separate 2 behaviors and, perhaps, depending on the specific type of  A  the data you provide.  
  Public category A {// general content} Public category AFTERType: A {public Int SomeInt {get; Set;}} Public category Escand type: A {public string string {get; Set;}} Public Category FT {public static zero (byte [] data) {// analyze data if (bulflame ANligged data is true ==) {typing new forefront ({{SomeInt = IntFromAnalyzedData}; } And {type new escondition ({{SomeString = StringFromAnalyzedData}; }}} /// Main Code Byte [] Data = Gate Data (); An AA = forex. Create (data); If (AAST type) dustf (as an ASFType) .SomeInt); And if (a escond type) dustf ((AS ASKCAND type). Some strings);