Last Updated - Thu Oct 05 2017

This topic intimidated me when it first presented itself to me, because let's face it a Web Service really looks like it just processes XML and objects serialized essentially into a text format. Once I did a little investigating I found that it really is not that hard and can be used for a good thing, including cross platform interactions.

The big secret is passing an array of bytes as a parameter and then using the BinaryWriter to store the bits to a file. The following example shows how to pass the byte array, a file name and a file MIME type to store the file locally. Of course the web server has to have write permissions on the destination folder.

    <WebMethod()> _

    Public
Sub
 UploadBinaryFile(ByVal
 data As
Byte
(), ByVal
 fileName As
String
, _

 ByVal
 fileType As
String
)

Dim

extension

String

'.bin'

 Dim
 sDestFolder As
String
 = String
.Empty

        If
 fileType.Equals('application/pdf'
) Then

            extension = '.pdf'

        ElseIf
 fileType.Equals('image/tiff'
) Then

            extension = '.tiff'

        ElseIf
 fileType.Equals('image/jpeg'
) Then

            extension = '.jpg'

        ElseIf
 fileType.Equals('image/gif'
) Then

            extension = '.gif'

        ElseIf
 fileType.Equals('image/png'
) Then

            extension = '.png'

        ElseIf
 fileType.Equals('image/zip'
) Then

            extension = '.zip'

Else

            extension = '.bin'

End

' This is not a complete routine, but enough to suffice for this demo.

        If
 fileName.EndsWith(extension) = False
Then

            fileName = fileName & extension

End

        fileName = sDestFolder & fileName

        Dim
 fs As
New
 FileStream(fileName, FileMode.OpenOrCreate)

        Dim
 w As
New
 BinaryWriter(fs)

For

Integer

= 0

data.Length - 1

            w.Write(data(i))

        w.Close()

        fs.Close()

End

Sub

Uploading a File Through a Web Service