How to send a byte array as json using Visual Basic 6? - json

Question

I have an Visual Basic 6 application which should read a file into a byte array, put that into a json object and make a post request to a rest API. I have everything working except the byte array part. When I use the code below, the API just receives the string "bytes" and not the actual content of the request that should look something like this "JVBERi0xLjQKJeLjz9MKCj"
Private Function PostDocumentPrint() As String
'Create http client
Dim http As Object
Set http = CreateObject("WinHttp.WinHttprequest.5.1")
url = "XXX"
http.Open "Post", url, False
'Set request parameters
http.SetRequestHeader "charset", "UTF-8"
http.SetTimeouts 500, 500, 500, 500
' Read file into byte array
Dim fileNum As Integer
Dim bytes() As Byte
fileNum = FreeFile
Open "FileToSend.pdf" For Binary As fileNum
ReDim bytes(LOF(fileNum) - 1)
Get fileNum, , bytes
Close fileNum
' Send the request
Dim jsonStringPostBody As String
jsonStringPostBody = " {""fileData"": "" " + bytes + """} "
http.Send jsonStringPostBody
End Function
I believe I need to convert the byte array to a string somehow. For example I tried this:
Dim s As String
s = StrConv(bytes, vbUnicode)
MsgBox s
But it does not look correct.