Message wenn sich die IP einer NIC ändert?

[SirThornberry]

ich hab mal nen Object gebaut welches mit Threads arbeitet:

Delphi-Quellcode:

unit uIPChanged;

interface

uses
  windows, classes, SysUtils;

type
  TIPChangedThread = class(TThread)
  private
    fChanged: TNotifyEvent;
    fRes    : DWord;
    procedure FSyncProc;
  protected
    procedure Execute; override;
  public
    constructor Create(ANotifyProc: TNotifyEvent);
  end;

  TIPChanged = class(TObject)
  private
    fEnabled  : Boolean;
    fOnChanged: TNotifyEvent;
    fThread   : TThread;
    procedure FNotifyProc(Sender: TObject);
  public
    constructor Create;
    destructor Destroy; override;

    property Enabled: Boolean read fEnabled write fEnabled default True;
    property OnChanged: TNotifyEvent read fOnChanged write fOnChanged;
  end;

  function NotifyAddrChange(AHandle: PCardinal; AOverlapped: POverlapped): DWORD; stdcall; External 'Iphlpapi.dll';

implementation

constructor TIPChanged.Create;
begin
  inherited Create;
  fEnabled := False;
  fThread  := TIPChangedThread.Create(FNotifyProc);
end;

destructor TIPChanged.Destroy;
begin
  if Assigned(fThread) then
    TerminateThread(fThread.Handle, 0);
  inherited Destroy;
end;

procedure TIPChanged.FNotifyProc(Sender: TObject);
begin
  fThread := nil;
  if Assigned(Sender) then
  begin
    if fEnabled and Assigned(fOnChanged) then
      fOnChanged(Self);
    fThread := TIPChangedThread.Create(FNotifyProc);
  end else
    raise Exception.Create('Überwachung der IP fehlgeschlagen.');
end;

constructor TIPChangedThread.Create(ANotifyProc: TNotifyEvent);
begin
  fChanged := ANotifyProc;
  inherited Create(True);
  FreeOnTerminate := True;
  Resume;
end;

procedure TIPChangedThread.Execute;
begin
  fRes := NotifyAddrChange(nil, nil);
  Synchronize(fSyncProc);
end;

procedure TIPChangedThread.FSyncProc;
begin
  if fRes = NOERROR then
    fChanged(Self)
  else
    fChanged(nil);
end;

end.

Einfach eine Instanz von TIPchanged erzeugen und das OnChanged zuweisen.