用Delphi怎么实现注册表路径检查

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    ImageList1: TImageList;
    SpeedButton1: TSpeedButton;
    Edit1: TEdit;
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    function TestHKey(const AHKey: string): Boolean;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function TForm1.TestHKey(const AHKey: string): Boolean;
var
  Reg: TRegistry;
  SourceKey: string;

  function GetRootKey(var AHKey: string): Cardinal;
  const
    cntHKEY_LOCAL_MACHINE = 'HKEY_LOCAL_MACHINE';
    cntHKEY_CLASSES_ROOT = 'HKEY_CLASSES_ROOT';
    cntHKEY_CURRENT_USER = 'HKEY_CURRENT_USER';
    cntHKEY_USERS = 'HKEY_USERS';
    cntHKEY_CURRENT_CONFIG = 'HKEY_CURRENT_CONFIG';
  var
    sRootKey: string;
  begin
    Result := 0;
    sRootKey := Copy(AHKey, 1, Pos('\', AHKey) -1);
    AHKey := Copy(AHKey, Pos('\', AHKey) +1, MaxInt);
    if sRootKey = cntHKEY_LOCAL_MACHINE then Result := HKEY_LOCAL_MACHINE;
    if sRootKey = cntHKEY_CLASSES_ROOT then Result := HKEY_CLASSES_ROOT;
    if sRootKey = cntHKEY_CURRENT_USER then Result := HKEY_CURRENT_USER;
    if sRootKey = cntHKEY_USERS then Result := HKEY_USERS;
    if sRootKey = cntHKEY_CURRENT_CONFIG then Result := HKEY_CURRENT_CONFIG;
  end;
begin
  if AHKey <> '' then
  begin
    SourceKey := AHKey;
    Reg := TRegistry.Create;
    try
      Reg.RootKey :=  GetRootKey(SourceKey);
      if Reg.RootKey = 0 then Application.MessageBox('Error Key', 'Warning', MB_OK);
      if Reg.OpenKeyReadOnly(SourceKey) then
        Application.MessageBox('路径有效', 'Warning', MB_OK)
      else
        Application.MessageBox('路径无效', 'Warning', MB_OK);
    finally
      Reg.Free;
    end;
  end;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  TestHKey(Edit1.Text);
end;

end.