This article was contributed by Jörg Dentler.

This is another Registry Class. 
CRegBinding is geared to make class member variables persistent in the registry. 
CRegBinding is easy to use.


The Class 
The following features are implemented:

1. Automatic variable binding

Adding persistence to variables 
Every value of registered variables would automatically read on startup.  
On class destruction the values of the variables are written back to the registry.

2. Window state binding

Adding persistence to your CWnd object
Binding a CWnd to the CRegBinding object lets you save the window state, 
size and position in the registry.


How to use CRegBinding 
In the Debug build the code contains many check routines 
that would detect improper use of the class object.

Step 1 - Place a CRegBinding member in your class declaration
In a class derived from CObject you can decide which member variables you want 
to bind to a CRegBinding object.Set the CRegBinding class member behind the 
last structure member.

For instance:

class A : public CDialog  // (CWnd)
{
     int         a;       
     CByteArray  b;      
     CString     c;      
     DWORD       dw;      
     CString     d;    
   // .    
   // .      
   // .      
   // .      
   // place the CRegBinding object here      
     CRegBinding   rs;      

     A();    
};


Step 2 - Make the bindings
After you have declared the class 'A' you should make the bindings in the 
class constructor or any other initializing member function. 
The third optional parameter of the Bind() function lets you specify 
a default value for initialization. 

A::A() : rs("My section")
{

  rs.Bind(a,  "a", 0);
  rs.Bind(dw, "DW", 0xfffffffa);
  rs.Bind(b,  "b");
  rs.Bind(c,  "C-Key", "CCC");
  rs.Bind(d,  "D-Key");

  CreateEx( ... );

  // After you have created the window, you can also bind the CWnd object
  rs.Bind(this, "Persistence Window");
}


If the window or class is about to be destroyed the current values of the 
variables are written back to the registry.

The Source
The library itself comes as two source files, CRegBinding.cpp and CRegBinding.h. 
The header defines the CRegBinding class with the following members:

CRegBinding::CRegBinding(const char *section)


Construct a new binding object taking the name of the section for the 
specified keys in the registration database


void CRegBinding::Bind(int        &value, const char *name, const int         def)
void CRegBinding::Bind(DWORD      &value, const char *name, const DWORD       def)
void CRegBinding::Bind(CString    &value, const char *name, const char       *def)
void CRegBinding::Bind(CByteArray &value, const char *name, const CByteArray *def)
void CRegBinding::Bind(CWnd       *value, const char *name)


Bind member variables of various types.

value:
The class member variable to bind.

name:
The name of the key in the registry.

def:
Optionally you can specify a default value if the key not exist.


void CRegBinding::Write(const BOOL clear)


Write data explicit to the registry. The parameter specifies whether 
to delete all bindings.