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...determine if a Comm Port is available?
Autor: Jorge A. Canevaro
[ Print tip ]  

Tip Rating (17):  
     


{
  This tip uses the API of Windows to determine
  if a this available certain COM.
  Port: COM1, COM2, COM3...
}

function ComPortAvailable(Port: PChar): Boolean;
var
  
DeviceName: array[0..80] of Char;
  ComFile: THandle;
begin
  
StrPCopy(DeviceName, Port);

  ComFile := CreateFile(DeviceName, GENERIC_READ or GENERIC_WRITE, 0, nil,
    OPEN_EXISTING,
    FILE_ATTRIBUTE_NORMAL, 0);

  Result := ComFile <> INVALID_HANDLE_VALUE;
  CloseHandle(ComFile);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if 
ComPortAvailable('COM1:') then
    
ShowMessage('Port available')
  else
    
ShowMessage('Port not available');
end;


 

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