How to check internet connection is available or not

[Cyclops]

There are several methods to check Internet connection availability and in this method try to open given URL for check the connection.

Code: Select all

'Declares for direct ping
Private Declare Function InternetOpen Lib "wininet.dll" Alias "InternetOpenA" (ByVal lpszAgent As String, ByVal dwAccessType As Long, ByVal lpszProxyName As String, ByVal lpszProxyBypass As String, ByVal dwFlags As Long) As Long
Private Declare Function InternetOpenUrl Lib "wininet.dll" Alias "InternetOpenUrlA" (ByVal hInet As Long, ByVal lpszUrl As String, ByVal lpszHeaders As String, ByVal dwHeadersLength As Long, ByVal dwFlags As Long, ByVal dwContext As Long) As Long
Private Declare Function InternetCloseHandle Lib "wininet.dll" (ByVal hInet As Long) As Long

Private Const INTERNET_OPEN_TYPE_PRECONFIG = 0
Private Const INTERNET_FLAG_RELOAD = &H80000000
Private Const INTERNET_FLAG_KEEP_CONNECTION = &H400000
Private Const INTERNET_FLAG_NO_CACHE_WRITE = &H4000000

Private Sub CheckConnection3()
   Dim sTmp As String
   Dim hInet As Long
   Dim hUrl As Long
   Dim Flags As Long
   Dim url As Variant
   hInet = InternetOpen(App.Title, INTERNET_OPEN_TYPE_PRECONFIG, vbNullString, vbNullString, 0&)
   
   
   If hInet Then
      Flags = INTERNET_FLAG_KEEP_CONNECTION Or INTERNET_FLAG_NO_CACHE_WRITE Or INTERNET_FLAG_RELOAD
      hUrl = InternetOpenUrl(hInet, "http://www.yahoo.com", vbNullString, 0, Flags, 0)
      If hUrl Then
         MsgBox "Your computer is connected to Internet", vbInformation, "Checing connection"
         Call InternetCloseHandle(hUrl)
      Else
         MsgBox "Your computer is not connected to Internet", vbInformation, "Checing connection"
      End If
   End If
   Call InternetCloseHandle(hInet)
   Me.Caption = sTmp
End Sub