asked on

RegOPenKeyEx not working

Hi all.

Another problem is driving me crazy! Below you find the code of a function which, do you guess? fails!

procedure TForm1.Stringvalue1Click(Sender: TObject);
var
  hOpenKey: HKEY;
  iI, iSize, iType: Integer;
  pcTemp: PByte;
  pdI: PDWORD;
  response: DWORD;
  error: string;
begin
  if (tvr.Selected = nil) or (tvr.Selected.Text = 'My Computer') then
    Exit
  else
  begin
    pdI := nil;
    response := RegOpenKeyEx(tvr.CurrentKey, PChar(tvr.ShortPath), 0, KEY_WRITE, hOpenKey);
//    response := RegOpenKeyEx(HKEY_CURRENT_USER, '000\CORBA Events\', 0, KEY_WRITE, hOpenKey);
    if response = ERROR_SUCCESS then
    begin
      ShowMessage('KEY OPEN');
      iType := REG_SZ;       // Type of data that is going to be read
      iSize := SizeOf(Integer); // Buffer for the value to read
      if RegQueryValueEx(hOpenKey, 'String Value', nil, @iType, pcTemp, @iSize)
        = ERROR_SUCCESS then
        ShowMessage('SET SUCCESS')
      else
        ShowMessage('SET FAILED');
      RegCloseKey(hOpenKey);
    end
    else
    begin
      ShowMessage('KEY NOT OPEN: '+ IntToStr(response));
    end;
  end;
end;

Open in new window

What happens here? In the commented line 17 you see the exact value passed with line 16. Let me explain variables used in line 16:

- tvr is TJvRegistryTreeView
- tvr.CurrentKey is a HKEY
- tvr.ShortPath is a string holding the current path without the HKEY value

Well: line 17 works, line 16 doesn't: please, I would have not only the solution but overall the explanation of waht is involving here.

As a side note, I have to admit that testing line 17 I saw that setting value doesn't work but this will be another question.

Thanks in advance to all

Cheers
Marco

ASKER CERTIFIED SOLUTION

Sinisa Vuk

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Marco Gasi

ASKER

Hi, sinisav: thanks for helping me.
Well, you're right (obviously): ShortPath returns a string with a leading backslash: once I removed it the key is correctly open.

About the rest, I simply copied and pasted the code from the web and I didn't analyze its core so I didn't notice it used RegQueryValueEx instead of RegSetValueEx: I want to create a new value. Now I have changed a bit the code but... it doesn't work. I open a new question about and I'll post here the link so you'll can help me in it too :-)

Cheers

Marco Gasi

ASKER

Thank you

Marco Gasi

ASKER

@sinissav, don't worry, I'm not dead yet :-) But I have to go away the next week, so it's not intelligent to post a new question knowing that I can't follow its answers. I'll cme back in 20-01
and I'll ask why I can't create new key in the damned Windows registry (do you guess? Right, my code doesn't work: what's a strang fact, uh?).

Cheers
Marco