Working with INI Files in Delphi

One of the reasons why INI files are still in use is the fact that they are easier and safer to approach than messing with the Registry and the fact that the system Registry is specific to Windows only. But it is also a fact that Windows Registry, which stores data in a hierarchical form and doesn't have a size limit, is more suited to present times. Delphi eases the transition from INI files to Registry or writing cross platform applications intended for both Windows and Linux systems by providing the TRegistryIniFile class. This class inherits all the of methods and properties of TCustomIniFile and can be used to read and write to the Registry in the same manner as writing to the INI file. In fact, the same code can be used to write to both an INI file and Windows Registry by adding a conditional in the code to provide an instance of TRegistryIniFile when it is running Windows and TMemIniFile when it is running Linux.

For instance, if the parameter you provide in the constructor of the TIniFile class results in the creation of an INI file of the same name, substituting it with TRegistryIniFile would make it create a subkey in the Registry's root key (eg HKEY_CURRENT_USER). The section of the INI file corresponds to the key in the system Registry and the key/value correspond to data values under the key. So if I were to modify the above code to instantiate TRegistryIniFile instead of the TIniFile class I don't have to code the entire block once more.

var
myIniFile:TRegistryIniFile;
begin
myIniFile:=TRegistryIniFile.Create('TestIni');
try
myIniFile.WriteString('TestCompanyInfo','CompanyName','mindfire');
finally
myIniFile.Free;
end;
end;

If you are porting an existing application to use Registry instead of INI files or are writing a cross-platform application, this approach can help you avoid writing that extra bit of code. If you want the ease of INI files and robustness of the Windows Registry without needing to write extra code, TRegistryIniFile class is what you need to use.

Danish Ahmed
Mindfire Solutions