Testen ob Internet-Verbindung besteht

[XeRo]

Versuchs einfach mal so:

Delphi-Quellcode:

uses 
  StdCtrls, registry; 

function IsConnected: Boolean; 
var 
  reg: TRegistry; 
  buff: DWORD; 
begin 
  reg := TRegistry.Create; 
  Reg.RootKey := HKey_local_machine; 
  if reg.OpenKey('\System\CurrentControlSet\Services\RemoteAccess', False) then 
  begin 
    reg.ReadBinaryData('Remote Connection', buff, SizeOf(buff)); 
    Result := buff = 1; 
    reg.CloseKey; 
    reg.Free; 
  end; 
end;

Ist zwar mit registry funktioniert aber gut...

Zweite Möglichkeit:

Delphi-Quellcode:

uses 
  WinInet; 

{...} 

function IsConnectedToInternet: Boolean; 
var 
  dwConnectionTypes: DWORD; 
begin 
  dwConnectionTypes := 
    INTERNET_CONNECTION_MODEM + 
    INTERNET_CONNECTION_LAN + 
    INTERNET_CONNECTION_PROXY; 
  Result := InternetGetConnectedState(@dwConnectionTypes, 0); 
end; 

procedure TForm1.Button1Click(Sender: TObject); 
begin 
  if IsConnectedToInternet then 
    ShowMessage('Connected.') 
  else 
    ShowMessage('Not Connected.') 
end;

Dritte Möglichkeit:

Delphi-Quellcode:

function IsConnectedToInternet(lpdwFlags: LPDWORD): Boolean; 
const 
  WininetDLL = 'wininet.dll'; 
var 
  hWininetDLL: THandle; 
  dwReserved: DWORD; 
  fn_InternetGetConnectedState: function(lpdwFlags: LPDWORD; dwReserved: DWORD): BOOL; stdcall; 
begin 
  Result := False; 
  dwReserved := 0; 
  hWininetDLL := LoadLibrary(WininetDLL); 
  if hWininetDLL > 0 then 
  begin 
    @fn_InternetGetConnectedState := GetProcAddress(hWininetDLL,'InternetGetConnectedState'); 
    if Assigned(fn_InternetGetConnectedState) then 
    begin 
      Result := fn_InternetGetConnectedState(lpdwFlags, dwReserved); 
    end; 
    FreeLibrary(hWininetDLL); 
  end else 
   raise Exception.Create('Unable to locate function InternetGetConnectedState in library ' + WininetDLL); 

end;

irgendwas sollte ja von denen deinen erwartungen entsprechen...