How to check Internet connection using Inno Setup - inno-setup

Question

I'm learning about Inno Setup to make a simple installer. I need to download a file from a website during the installation, so it's important check if there is Internet connection. How can I check or take some alert to connect Internet during the process of the installation?
Thanks!

Answer 1

The best check is to try to actually download the file.
"Internet" is hardly a real thing that you can connect to. So it's hard to test, if you are connected to "Internet". You actually do not need a connection to "Internet", you need a connection to your server. So test that.
See also
How to check if internet connection is present in java?
What is the best way to check for Internet connectivity using .NET?
An equivalent implementation in Inno Setup would be like:
function InitializeSetup(): Boolean;
var
WinHttpReq: Variant;
Connected: Boolean;
begin
Connected := False;
repeat
Log('Checking connection to the server');
try
WinHttpReq := CreateOleObject('WinHttp.WinHttpRequest.5.1');
{ Use your real server host name }
WinHttpReq.Open('GET', 'https://www.example.com/', False);
WinHttpReq.Send('');
Log('Connected to the server; status: ' + IntToStr(WinHttpReq.Status) + ' ' +
WinHttpReq.StatusText);
Connected := True;
except
Log('Error connecting to the server: ' + GetExceptionMessage);
if WizardSilent then
begin
Log('Connection to the server is not available, aborting silent installation');
Result := False;
Exit;
end
else
if MsgBox('Cannot reach server. Please check your Internet connection.',
mbError, MB_RETRYCANCEL) = IDRETRY then
begin
Log('Retrying');
end
else
begin
Log('Aborting');
Result := False;
Exit;
end;
end;
until Connected;
Result := True;
end;