I've successfully used UDP in a very simple B4J app for several years to remotely trigger button click events in another B4J app. I wanted to expand this so that as well as triggering a button click in the B4J app, I wanted to trigger a button click in a B4A app.
Here is the relevant code:
However it seems while the first packet is always sent and received successfully, the second packet (on a different port), is not always received.
Is there something fundamentally wrong with my code? Or because I'm using a broadcast IP address rather than specific IP addresses for the two separate devices running the B4J and B4A apps, is the second packet somehow consumed before reaching the intended B4A app? Would a small delay between UDP sends help?
In any case, I'd appreciate the comments from others more knowledgeable than me in regard to UDP.
Here is the relevant code:
B4X:
Sub Process_Globals
Private Packet1, Packet2 As UDPPacket
Private data1() As Byte
Private data2() As Byte
Private TxPort1 As Int = 3661 ' To PlayerBoard
Private TxPort2 As Int = 3662 ' To Effects Controller
Private UDPSocket1, UDPSocket2 As UDPSocket
Private broadcastIP As String
Private HostIPAddress As TextField
End Sub
Sub AppStart (Form1 As Form, Args() As String)
MainForm = Form1
MainForm.RootPane.LoadLayout("1") 'Load the layout file.
MainForm.Title = title
MainForm.Icon = fx.LoadImage(File.DirAssets,"IMG_41.gif")
MainForm.Show
imgBDS.SetImage(fx.LoadImage(File.DirAssets,"BDSConsulting.png"))
' Get client IP address
Dim JO As JavaObject
JO.InitializeStatic("java.net.InetAddress")
Dim JO2 As JavaObject = JO.RunMethod("getLocalHost", Null)
Dim objHostAddress As Object = JO2.RunMethod("getHostAddress", Null)
Dim ip As String = objHostAddress
ClientIPAddress.Text = "Client IP Address: " & ip
HostIPAddress.Text = ip
Dim Port As Int = 3663
UDPSocket1.Initialize("UDP", Port, 8000)
Dim Port As Int = 3664
UDPSocket2.Initialize("UDP", Port, 8000)
broadcastIPCalc
End Sub
Sub btnPlayerIntros_Click
data1 = "Intros".GetBytes("UTF8")
Packet1.Initialize(data1, broadcastIP, TxPort1)
UDPSocket1.Send(Packet1)
data2 = "NBL1_Intro".GetBytes("UTF8")
Packet2.Initialize(data2, broadcastIP, TxPort2)
UDPSocket2.Send(Packet2)
End Sub
Sub broadcastIPCalc
Dim partip As String = HostIPAddress.Text
Dim x As Int = partip.LastIndexOf(".")
partip = partip.SubString2(0, x)
broadcastIP = partip & ".255"
End SubHowever it seems while the first packet is always sent and received successfully, the second packet (on a different port), is not always received.
Is there something fundamentally wrong with my code? Or because I'm using a broadcast IP address rather than specific IP addresses for the two separate devices running the B4J and B4A apps, is the second packet somehow consumed before reaching the intended B4A app? Would a small delay between UDP sends help?
In any case, I'd appreciate the comments from others more knowledgeable than me in regard to UDP.