Internet Connection

[Guest_imported]

How my delphi-program can know when my computer is connected to internet?

 

[DelphiGuru]

Hi,
You can know whether computer is connected to net or not using Windows system registry.
Just explore the following using code

HKEY_LOCAL_MACHINE
\System\CurrentControlSet\Services\RemoteAccess

and from RemoteAccess access the binary value
'Remote Connection'.
if values obtained is "1" then computer is connected.

Hope it will help you.

Ali Naqvi

 

[Guest_imported]

How i can read the binary value?
Debugger says:
[Error] Unit1.pas(44): Constant object cannot be passed as var parameter
[Error] Unit1.pas(16): Unsatisfied forward or external declaration: 'TForm1.ReadBinaryData'
[Fatal Error] Project2.dpr(5): Could not compile used unit 'Unit1.pas'

 

[DelphiGuru]

Hi,
Seems from your message errors that you didnt' understand what i meant to. Acutally all you've to do is use registry unit in your uses clause, create an instance of TRegistry and use TRegistry's ReadBinaryData function.

for example


var
reg : TRegistry;
begin
reg := TRegistry.Create;
try
//Set the registry's root path and use openkey to open
the key i've mentioned in my previous msg.
//use reg.ReadBinaryDate(Key,buffer,sizeof(buffer)
// check the value of buffer as buffer parameter is
// passed by reference. if it is '1' then connected
finally
reg.Free;
end;
end;

 

[DelphiGuru]

Hi,
Seems from your message errors that you didnt' understand what i meant to. Acutally all you've to do is use registry unit in your uses clause, create an instance of TRegistry and use TRegistry's ReadBinaryData function.

for example


var
reg : TRegistry;
begin
reg := TRegistry.Create;
try
//Set the registry's root path and use openkey to open
the key i've mentioned in my previous msg.
//use reg.ReadBinaryDate(Key,buffer,sizeof(buffer)
// check the value of buffer as buffer parameter is
// passed by reference. if it is '1' then connected
finally
reg.Free;
end;
end;


Hope it will help you.

Ali Naqvi

 

[Guest_imported]

Why this code doesn't work?
The registry unist is in uses clause.


var
Form1: TForm1;
Reg : TRegistry;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
X : Integer;
begin
Reg.ReadBinaryData('Remote Connection', 12, 12): X;
Label1.Caption := IntToStr(X);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
Reg := TRegistry.Create;
Reg.RootKey := HKEY_LOCAL_MACHINE;
Reg.OpenKey('System\CurrentControlSet\Services\RemoteAccess', False);
end;

procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
Reg.Free;
end;

end.

 

[DelphiGuru]

Hi,
the only problem with your code is with the use of ReadBinaryDate function.
that function in delphi is defined as

function ReadBinaryData(const Name: string; var Buffer; BufSize: Integer): Integer;

as here u can see the 2nd parameter is passed by reference and you can't pass it constant.

change your Reg.ReadBinaryData function to sth. like this

Reg.ReadBinaryData('Remote Connection',X,Sizeof(X));

Ali Naqvi