Xojo Plugin

Socket Send/Receive 16-bit Integers

Demonstrates sending and receiving 16-bit integers over a socket connection using either big-endian or little-endian byte ordering. Xojo Plugin

Dim success As Boolean
success = False

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Dim sock As New Chilkat.Socket

// --------------------------------------------------------------------
// This example uses the public TCP echo service at https://tcpbin.com/
// --------------------------------------------------------------------

Dim useTls As Boolean
useTls = False
Dim port As Int32
port = 4242
Dim maxWaitMs As Int32
maxWaitMs = 5000
success = sock.Connect("tcpbin.com",port,useTls,maxWaitMs)
If (success = False) Then
    System.DebugLog(sock.LastErrorText)
    Return
End If

// Wait a max of 2 seconds for a response..
sock.MaxReadIdleMs = 2000

// Send a 16-bit integer using big-endian byte ordering (also called network byte order)
// 12022 decimal = 2EF6 hex
Dim value As Int32
value = 12022
Dim bigEndian As Boolean
bigEndian = True
success = sock.SendInt16(value,bigEndian)
// Send it again, because we'll read it two different ways..
success = sock.SendInt16(value,bigEndian)

// The tcpbin.com echo server only echoes after receiving an LF (linefeed char)
success = sock.SendByte(10)

// Let's see hex values of the 2 bytes sent in network byte order (big-endian)
// (The echo server sends back exactly the bytes received.)
Dim hexStr As String
hexStr = sock.ReceiveNBytesENC(2,"hex")

// In the big-ending byte order, the byte order is most significant byte to least significant,
// therefore we should see the bytes in the order 0x2E 0xF6.
System.DebugLog("Expecting big-endian 2EF6")
System.DebugLog(hexStr)

// Let's read directly to an integer..
success = sock.ReceiveInt16(bigEndian,True)
System.DebugLog("Expecting 12022")
System.DebugLog("Received: " + Str(sock.ReceivedInt))

// Consume the LF that gets echoed back..
success = sock.ReceiveByte(True)

// --------------------------------------------------------------------
// Let's do the same thing, but with little-endian byte ordering.

System.DebugLog("----")

// 12022 decimal = 2EF6 hex, but little-endian byte ordering will send the bytes in the order 0xF6 0x2E
value = 12022
bigEndian = False
success = sock.SendInt16(value,bigEndian)
success = sock.SendInt16(value,bigEndian)
success = sock.SendByte(10)

hexStr = sock.ReceiveNBytesENC(2,"hex")

System.DebugLog("Expecting little-endian F62E")
System.DebugLog(hexStr)

success = sock.ReceiveInt16(bigEndian,True)
System.DebugLog("Expecting 12022")
System.DebugLog("Received: " + Str(sock.ReceivedInt))

// Consume the LF that gets echoed back..
success = sock.ReceiveByte(True)

success = sock.Close(1000)

// Output:

// Expecting big-endian 2EF6
// 2EF6
// Expecting 12022
// Received: 12022
// ----
// Expecting little-endian F62E
// F62E
// Expecting 12022
// Received: 12022