URLEncode in UTF-8 with Visual Basic 6 (Sending Unicode SMS message)

[labmany]

After searching this forum and the internet for a few days and did not get what I am looking for I stumbled upon this and tweaked it a little bit because it had a problem with encoding vbCrLf.

It all started when I tried to add SMS capability to an old VB6 application using ClickaTell service but unfortunately it only uses CURL or JavaScript!
Sending Unicode SMS from VB6 app wasn't possible till I found this and I thought I'd share as it may come handy to others.

Private Declare Sub CopyToMemory Lib "kernel32" Alias "RtlMoveMemory" (lpvDest As Any, lpvSource As Any, ByVal cbCopy As Long)

Public Function URLEncode_UTF8( _
      ByVal Text As String _
   ) As String
 
   Dim Index1 As Long
   Dim Index2 As Long
   Dim Result As String
   Dim Chars() As Byte
   Dim Char As String
   Dim Byte1 As Byte
   Dim Byte2 As Byte
   Dim UTF16 As Long
 
   For Index1 = 1 To Len(Text)
      CopyToMemory Byte1, ByVal StrPtr(Text) + ((Index1 - 1) * 2), 1
      CopyToMemory Byte2, ByVal StrPtr(Text) + ((Index1 - 1) * 2) + 1, 1
 
      UTF16 = Byte2
      UTF16 = UTF16 * 256 + Byte1
      Chars = GetUTF8FromUTF16(UTF16)
      For Index2 = LBound(Chars) To UBound(Chars)
         Char = Chr(Chars(Index2))
         If Char Like "[0-9A-Za-z]" Then
            Result = Result & Char
         Else
            If Asc(Char) < 16 Then
                Result = Result & "%0" & Hex(Asc(Char))
            Else
                Result = Result & "%" & Hex(Asc(Char))
            End If
         End If
      Next
   Next
   
   URLEncode_UTF8 = Result
   
End Function
 
Private Function GetUTF8FromUTF16( _
      ByVal UTF16 As Long _
   ) As Byte()
 
   Dim Result() As Byte
   If UTF16 < &H80 Then
      ReDim Result(0 To 0)
      Result(0) = UTF16
   ElseIf UTF16 < &H800 Then
      ReDim Result(0 To 1)
      Result(1) = &H80 + (UTF16 And &H3F)
      UTF16 = UTF16 \ &H40
      Result(0) = &HC0 + (UTF16 And &H1F)
   Else
      ReDim Result(0 To 2)
      Result(2) = &H80 + (UTF16 And &H3F)
      UTF16 = UTF16 \ &H40
      Result(1) = &H80 + (UTF16 And &H3F)
      UTF16 = UTF16 \ &H40
      Result(0) = &HE0 + (UTF16 And &HF)
   End If
   GetUTF8FromUTF16 = Result
End Function

VB6 code to use CURL is as follow after adding a reference to Microsoft Internet Controls :

Inet1.Execute "https://platform.clickatell.com/messages/http/send?apiKey=YourKey&to=MobileNo&content=" & URLEncode_UTF8(YourMessage)

Enjoy!