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Posted 19 Sep 2002


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CRegSettings - registry helper class

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4.97/5 (15 votes)
7 Oct 20023 min read
Simple class to store application settings in registry


It's so tedious to use Win32 API or even CRegKey helper class to save/load configuration values to/from registry. This class uses DDX-like metaphors to map class member variables to registry data. It is very simple to use and smart enough for most typical registry usage.

How to use

  1. Include rsettings.h into your project
  2. Declare class that will contain configuration values and define map with BEGIN_REG_MAP and END_REG_MAP:
    // Sample application configuration
    class CMySettings : public CRegSettings
        DWORD Value1; // DWORD option
        CString Value2; // String option
        DWORD RequiredValue;
            REG_ITEM(Value1, 1)
            REG_ITEM(Value2, "Default Value")
  3. That’s All! Now you can save or load values:

    CMySettings settings(HKEY_CURRENT_USER,
            "Software\\My Company\\Application\\1.0");
    settings.Load(); // Load configuration
    ... // use values settings.Value1 etc.
    settings.Save(); // Save configuration

CRegSettings constructor can be called with variable number of parameters:

CMySettings settings(HKEY_CURRENT_USER, "Software\\%s\\%s\\%i",
   "My Company", "My Application", Version);

Supported types

Variables mapped to corresponding keys and values in registry:

Variable typeRegistry data type
void* (structs, arrays etc.) REG_BINARY
CSimpleArray<T>* Sub-keys

* - T must be inherited from CRegSettings and must contain map declared with BEGIN_REG_MAP - END_REG_MAP

Macros reference

BEGIN_REG_MAP(Name of class) - Marks the beginning of the registry map.

END_REG_MAP() - Marks the end of the registry map.

REG_ITEM(VarName, DefaultValue) - Maps variable to registry value. Registry value will be named "VarName". If the value doesn't exist in registry when loading then variable will be assigned to DefaultValue. Variable can be of one of the following types: DWORD, int, long, bool, char, wchar_t, CString.

REG_ITEM_REQUIRE(VarName) - Same as REG_ITEM, but you cannot specify default value. And Load() call will fail if the value doesn't exist in registry.

REG_ITEM_SUBKEY(VarName) - Maps class inherited from a CRegSettings to sub-key. The class must contain map declared with BEGIN_REG_MAP - END_REG_MAP. See sample application.

REG_ITEM_SIMPLE_ARRAY(VarName) - Maps ATL template class CSimpleArray<T> to registry. T must be inherited from CRegSettings and must have map declared with BEGIN_REG_MAP - END_REG_MAP. Array items will be saved under sub-keys in registry. See sample application.

REG_ITEM_VECTOR(VarName) - Same as REG_ITEM_SIMPLE_ARRAY, but forstd::vector type.

REG_ITEM_LIST(VarName) - Same as REG_ITEM_SIMPLE_ARRAY, but for std::list type.

REG_ITEM_SZ(VarName, DEFAULT_VALUE) - Maps C string (TCHAR*) to registry value (REG_SZ). The registry value will be named "VarName". If the value doesn't exist in registry when loading then variable will be assigned to DefaultValue.

REG_ITEM_SZ_REQUIRE(VarName) - Same as REG_ITEM_SZ, but you cannot specify default value. And Load() call will fail if the value doesn't exist in registry.

REG_ITEM_SZ_LEN(VarName, DEFAULT_VALUE, VarLen) - Same as REG_ITEM_SZ with the additional parameter VarLen used to specify buffer size in TCHARs.

REG_ITEM_SZ_REQUIRE_LEN(VarName, VarLen) - Same as REG_ITEM_SZ_REQUIRE with the additional parameter VarLen used to specify buffer size in TCHARs.

REG_ITEM_BINARY(VarName) - Maps any type to registry value (REG_BINARY). The registry value will be named "VarName". Useful with structures, arrays etc. Size of binary data is calculated through sizeof(VarName).

REG_ITEM_BINARY_SIZE(VarName, VarSize) - Same as REG_ITEM_BINARY with the additional parameter VarSize which specifies variable size.

REG_ITEM_STL(VarName, DefaultValue) and REG_ITEM_STL_REQUIRE(VarName) - Same as REG_ITEM and REG_ITEM_REQUIRE. Maps std::string to REG_SZ.


  • 7.10.2002
    • OnBeforeSave, OnAfterLoad virtual methods;
    • Bugs fixed.
  • 25.09.2002
    • REG_ITEM_SUBKEY: store data in sub keys 
    • REG_ITEM_BINARY,REG_ITEM_BINARY_SIZE: store binary data (void*, structs, etc.) 
    • REG_ITEM_SZ_REQUIRE_LEN: store C strings (TCHAR*) 
    • REG_ITEM and REG_ITEM_REQUIRED enhanced to support: bool, int, char and wchar_t
  • 19.09.2002
    • Created


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Comments and Discussions

GeneralGood code! thanks for your help Pin
Ryan McDermott18-Mar-04 7:33
Ryan McDermott18-Mar-04 7:33 
Hey again. What a dope I am for not being able to get a space between the values. I don't do much registry stuff but your tip and your code helped me a lot. I wrote another way to add registry entries

#include <windows.h>
#include "stdafx.h"

char buffer[60];
unsigned long size = sizeof(buffer);
HKEY software;
HKEY mykey;

VERY SIMPLE!Cool | :cool:

-Ryan M.
Generalloading .reg file programmatically Pin
bruno leclerc18-Mar-04 1:12
bruno leclerc18-Mar-04 1:12 
GeneralRe: loading .reg file programmatically Pin
yamei13-Oct-04 4:46
yamei13-Oct-04 4:46 
GeneralThis is great! Pin
Rui Jiang3-Mar-04 18:46
Rui Jiang3-Mar-04 18:46 
GeneralI can't get a space between the values Pin
14-Feb-04 15:45
suss14-Feb-04 15:45 
GeneralRe: I can't get a space between the values Pin
Magomed Abdurakhmanov15-Feb-04 20:43
Magomed Abdurakhmanov15-Feb-04 20:43 
QuestionWhy use CString? Pin
Anonymous16-Oct-02 8:54
Anonymous16-Oct-02 8:54 
GeneralA minor enhancement Pin
Ales Krajnc14-Oct-02 21:54
Ales Krajnc14-Oct-02 21:54 
GeneralRe: A minor enhancement Pin
Magomed Abdurakhmanov15-Oct-02 1:42
Magomed Abdurakhmanov15-Oct-02 1:42 
GeneralUnlock Pentential! Pin
Joel Holdsworth7-Oct-02 8:21
Joel Holdsworth7-Oct-02 8:21 
GeneralRe: Unlock Pentential! Pin
Magomed Abdurakhmanov7-Oct-02 9:41
Magomed Abdurakhmanov7-Oct-02 9:41 
GeneralThanks.But.... Pin
Leafdown23-Sep-02 8:07
Leafdown23-Sep-02 8:07 
GeneralRe: Thanks.But.... Pin
Magomed Abdurakhmanov24-Sep-02 13:31
Magomed Abdurakhmanov24-Sep-02 13:31 

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