Registry: Verknüpfen mit Programm

[rebugger]

Habe einen Verknüpfungs-Dialog für mein Programm.
Habe dazu eine TCheckListBox mit dem Inhalt:
.php
.html
...

Quellcode:

Delphi-Quellcode:

unit unit_shortcuts;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, Registry, StdCtrls, CheckLst;

type
  TfrmFileShortcuts = class(TForm)
    listShortcuts: TCheckListBox;
    btnClose: TButton;
    btnSave: TButton;
    procedure FormCreate(Sender: TObject);
    procedure btnCloseClick(Sender: TObject);
    procedure btnSaveClick(Sender: TObject);
    procedure FormShow(Sender: TObject);
  private
    { Private-Deklarationen }
  public
    { Public-Deklarationen }
  end;

var
  frmFileShortcuts: TfrmFileShortcuts;

implementation

uses
  unit_main;

{$R *.dfm}

function AddCommand(Extension, Command, OpenWith, ParamString: STRING; Asdefault: BOOLEAN):BOOLEAN;
var
  Reg: TRegistry;
  ExtType: String;
begin
  Reg := TRegistry.Create;
  try
    with Reg do
    begin
      RootKey := HKEY_CLASSES_ROOT;
      OpenKey(Extension, True);
      ExtType := ReadString('');
      if ExtType = '' then
      begin
        if Reg.KeyExists('\' + Extension + '\Shell\' + Command + '\Command') = FALSE then
          Reg.CreateKey('\' + Extension + '\Shell\' + Command + '\Command');

        OpenKey('\' + Extension + '\Shell\' + Command + '\Command', True);
        WriteString('', '"' + OpenWith + '" "' + ParamString + '"');

        if Reg.KeyExists('\' + Extension + '\DefaultIcon') = FALSE then
          Reg.CreateKey('\' + Extension + '\DefaultIcon');

        OpenKey('\' + Extension + '\DefaultIcon', True);
        WriteString('', Application.ExeName + ',0');

        if AsDefault then
        begin
          OpenKey('\' + Extension + '\Shell', True);
          WriteString('', Command);
        end;
      end
      else
      begin
        if Reg.KeyExists('\' + Extension + '\Shell\' + Command + '\Command') = FALSE then
          Reg.CreateKey('\' + Extension + '\Shell\' + Command + '\Command');

        OpenKey('\' + ExtType + '\Shell\'+Command+ '\Command', True);
        WriteString('', '"' + OpenWith + '" "' + ParamString + '"');

        if Reg.KeyExists('\' + Extension + '\DefaultIcon') = FALSE then
          Reg.CreateKey('\' + Extension + '\DefaultIcon');

        OpenKey('\' + Extension + '\DefaultIcon', True);
        WriteString('', Application.ExeName + ',0');

        if AsDefault then
        begin
          OpenKey('\' + ExtType + '\Shell', True);
          WriteString('', Command);
        end;
      end;
    end;
    result := true;
  except
    result := False;
  end;
  Reg.Free;
end;

function ShowCommand(Extension, OpenWith: STRING):BOOLEAN;
var
  Reg: TRegistry;
  ExtType: String;
begin
  Reg := TRegistry.Create;
  try
    with Reg do
    begin
      RootKey := HKEY_CLASSES_ROOT;
      OpenKey(Extension, True);
      ExtType := ReadString('');
      if ExtType = '' then
      begin
        OpenKey('\' + Extension + '\Shell\Open\Command', True);
        if Pos(Application.ExeName, ReadString('')) > 0 then
          result := true
        else
          result := false;
      end
      else
        result := false;
    end;
  except
    result := false;
  end;
  Reg.Free;
end;

procedure TfrmFileShortcuts.FormCreate(Sender: TObject);
begin
  AddCommand('.php', 'Open', Application.ExeName, '%1', TRUE);
end;

procedure TfrmFileShortcuts.btnCloseClick(Sender: TObject);
begin
  Close;
end;

procedure TfrmFileShortcuts.btnSaveClick(Sender: TObject);
var
  i: Integer;
begin
  for i:=0 to (listShortcuts.Count - 1) do
    if listShortcuts.Checked[i] = TRUE then
      AddCommand(listShortcuts.Items.Strings[i], 'Open', Application.ExeName, '%1', TRUE);

  Close;
end;

procedure TfrmFileShortcuts.FormShow(Sender: TObject);
var
  i: Integer;
begin
  for i:=0 to (listShortcuts.Count - 1) do
    listShortcuts.Checked[i] := ShowCommand(listShortcuts.Items.Strings[i], Application.ExeName);
end;

end.

Probleme:
1. Wenn der Dialog geöffnet wird, soll er die Items anhaken, die bereits mit meinem Programm verknüpft sind (macht er nicht)
2. Das verknüpfen beim Schließen erfolgt auch nicht (vielleicht fehlerhaft)