Author: William Gerbert 

I am making a program for editing the registry. It will basically be the same as 
regedit, but with some added features. What I want to know is how should I go about 
reading the registry into my TreeView and ListView components and how do I specify 
which icons to use in the tree view? I know you can load files into a list view 
using the FindFirst, FindNext and FindClose, but how do you loop through the keys 
in the registry?

Answer:

Enumerating registry keys:


1   procedure TForm1.Button1Click(Sender: TObject);
2   var
3     indent: Integer;
4   
5     procedure EnumAllKeys(hkey: THandle);
6     var
7       l: TStringList;
8       n: Integer;
9     begin
10      Inc(indent, 2);
11      with TRegistry.Create do
12      try
13        RootKey := hkey;
14        OpenKey(EmptyStr, false);
15        l := TStringLIst.Create;
16        try
17          GetKeynames(l);
18          CloseKey;
19          for n := 0 to l.Count - 1 do
20          begin
21            memo1.lines.add(StringOfChar(' ', indent) + l[n]);
22            if OpenKey(l[n], false) then
23            begin
24              EnumAllKeys(CurrentKey);
25              CloseKey;
26            end;
27          end;
28        finally
29          l.Free
30        end;
31      finally
32        Free;
33      end;
34      Dec(indent, 2);
35    end;
36  begin
37    memo1.Clear;
38    memo1.lines.add('Keys under HKEY_CURRENT_USER');
39    indent := 0;
40    EnumAllKEys(HKEY_CURRENT_USER);
41  end;