Android Question no udp broadcast address is returned

[lewi]

Hi all,

in my project i'm using this snippet to get udp broadcast address

'Returns the UDP broadcast address.
'Returns an empty string if not available.
Sub GetBroadcastAddress As String
   Dim niIterator As JavaObject
   niIterator = niIterator.InitializeStatic("java.net.NetworkInterface").RunMethod("getNetworkInterfaces", Null)
   Do While niIterator.RunMethod("hasMoreElements", Null)
     Dim ni As JavaObject = niIterator.RunMethod("nextElement", Null)
     If ni.RunMethod("isLoopback", Null) = False Then
       Dim addresses As List = ni.RunMethod("getInterfaceAddresses", Null)
       For Each ia As JavaObject In addresses
         Dim broadcast As Object = ia.RunMethod("getBroadcast", Null)
         If broadcast <> Null Then
           Dim b As String = broadcast
           Return b.SubString(1)
         End If
       Next
     End If
   Loop
   Return ""
End Sub

but it always return empty string.
I can receive udp packets.
I can send udp packets but using hardcoded address 192.168.0.255
what could be the cause?

Many thanks.

here is the content of manifest

'This code will be applied to the manifest file during compilation.
'You do not need to modify it in most cases.
'See this link for for more information: https://www.b4x.com/forum/showthread.php?p=78136
AddManifestText(
<uses-sdk android:minSdkVersion="28" android:targetSdkVersion="33"/>
<supports-screens android:largeScreens="true"
    android:normalScreens="true"
    android:smallScreens="true"
    android:anyDensity="true"/>)
AddPermission("android.permission.INTERNET")
SetActivityAttribute(ViewCam, android:screenOrientation, "landscape")
SetApplicationAttribute(android:icon, "@drawable/icon")
SetApplicationAttribute(android:label, "$LABEL$")
SetApplicationAttribute(android:allowBackup, "false")
CreateResourceFromFile(Macro, Themes.DarkTheme)
SetApplicationAttribute(android:usesCleartextTraffic, "true")
'End of default text.

 

[Erel]

Worth trying with UdpSocket.GetBroadcardAddress. Note that you can call it without initializing the packet.