Modify a resource string at runtime

Problem/Question/Abstract:

How to modify a resource string at runtime

Answer:

{Modify a resourcestring constant:

Parameters:
Resstring is a pointer to a TResStringRec describing a resourcestring constant.
If this parameter is nil the function returns false.

Newvalue points to a zero-terminated string that should be the new value of the
resourcestring. This pointer must be guaranteed to stay valid for the lifetime of the
program! It should point to a constant string (a literal).

Returns true if the change was successful, false if not.
Precondition: newvalue <> nil
Will not work in Kylix! }

function ChangeResourceString(resstring: PResStringRec; newvalue: PChar): Boolean;
var
  oldprotect: DWORD;
begin
  Result := false;
{$IFDEF LINUX}

Thisfunction does not work in Kylix!{$ENDIF}
if resstring = nil then
  Exit;
Assert(Assigned(newvalue), 'ChangeResourceString: newvalue must be <> nil');
Result := VirtualProtect(resstring, Sizeof(resstring^), PAGE_EXECUTE_READWRITE,
  @oldProtect);
if Result then
begin
  resstring^.Identifier := Integer(newvalue);
  VirtualProtect(resstring, SizeOf(resstring^), oldProtect, @oldProtect);
end;
end;

Used like this:

resourcestring
  TestStr = 'Hello World';

procedure TForm1.Button1Click(Sender: TObject);
begin
  label1.caption := TestStr;
  ChangeResourceString(pResStringRec(@TestStr), 'Some test text');
  label2.caption := TestStr;
end;