Обновлено: 01 декабря, 2018

Как корректно определить изменения в оборудовании в Delphi?

type
  TForm1 = class(TForm) 
    Button1: TButton; 
  private
  { Private declarations }
    procedure WMDeviceChange(var Message: TMessage); 
    message WM_DEVICECHANGE; 
  public
  { Public declarations }
end; 
  
var
  Form1: TForm1; 
  
implementation
  
{$R *.DFM}
  
  const DBT_DEVICEARRIVAL = $8000; 
  const DBT_DEVICEQUERYREMOVE = $8001; 
  const DBT_DEVICEQUERYREMOVEFAILED = $8002; 
  const DBT_DEVICEREMOVEPENDING = $8003; 
  const DBT_DEVICEREMOVECOMPLETE = $8004; 
  const DBT_DEVICETYPESPECIFIC = $8005; 
  const DBT_CONFIGCHANGED = $0018; 
procedure TForm1.WMDeviceChange(var Message: TMessage); 
var
  s : string; 
begin
  {Do Something here}
  case Message.wParam of
    DBT_DEVICEARRIVAL: s:= 'A device has been inserted and is now available'; 
    DBT_DEVICEQUERYREMOVE: begin
                             s:= 'Permission to remove a device is requested'; 
                             ShowMessage(s); 
                             {True grants premission}
                             Message.Result := integer(true); 
                             exit; 
                           end; 
    DBT_DEVICEQUERYREMOVEFAILED: s := 'Request to remove a device has been canceled'; 
    DBT_DEVICEREMOVEPENDING : s := 'Device is about to be removed'; 
    DBT_DEVICEREMOVECOMPLETE : s := 'Device has been removed'; 
    DBT_DEVICETYPESPECIFIC : s := 'Device-specific event';
    DBT_CONFIGCHANGED : s:= 'Current configuration has changed'
    else s := 'Unknown Device Message'; 
  end; 
  ShowMessage(s); 
  inherited; 
end; 

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