title: Linker error: "LNK2019: Unresolved external symbol"
body: <p>I am getting linker errors and can not make out the source of the problem. I hope you can help me! The error occurs already when creating an object of the class <code>ClMyClass</code>.</p>
  
  <p>The two errors:</p>
  
  <pre><code>Error   18  error LNK2019: unresolved external symbol "public: virtual __thiscall ClMyClass::~ClMyClass(void)" (??1ClMyClass@@UAE@XZ) referenced in function "void __cdecl Test1(void)" (?Test1@@YAXXZ)
  
  Error   19  error LNK2019: unresolved external symbol "public: __thiscall ClMyClass::ClMyClass(void)" (??0ClMyClass@@QAE@XZ) referenced in function "void __cdecl Test1(void)" (?Test1@@YAXXZ)  
  
  
  //Test.cpp
  #include "StdAfx.h"
  #include "MyClass.hpp"
  
  void Test1(){
  
   ClMyClass oHandle;
  }
  
  //ClMyClass.hpp
  
  class ClMyClass: public ClMyClassBase
  {
  public: 
      ClMyClass(void);
      virtual ~ClMyClass(void);
  
  //methods...
  
  }
  
  
  //ClMyClass.cpp
  
  ClMyClass::ClMyClass(void):ClMyClassBase(),m_nCallbackError(ERROR_NOT_INITIALIZED), m_eState(eUnknown)
  {   
      //initialize members
  }
  
  ClMyClass::~ClMyClass(void)
  {
      Unassign();
  }
  </code></pre>
  
  <p>EDIT: Added .cpp file</p>