Reading/Uploading Image data using base64 string

How will you upload an image from your local drive without using File Upload control or you do not want to click browse button in order to select and upload the image file. Here is an alternate solution. I came across a situation in which I had to upload an Image file from local drive without using server side File Upload control already available in .NET.

 Client Side Code

The following example illustrates a VBScript Client side function using ADODB Stream and MSXML2 DOMDocument Object.

   1: <script language="vbscript" type="text/vbscript">

   2:  

   3:    'fileName can be any file including full path on your local drive

   4:  

   5:     Function PostImageData(ByVal fileName)

   6:        Const fsDoOverwrite     = true  ' Overwrite file with base64 code

   7:        Const fsAsASCII         = false ' Create base64 code file as ASCII file

   8:        Const adTypeBinary      = 1     ' Binary file is encoded

   9:        Dim objXML,objDocElem

  10:        Dim objStream, objFSO

  11:                

  12:        Set objXML = CreateObject("MSXml2.DOMDocument")

  13:        Set objDocElem = objXML.createElement("Base64Data")

  14:  

  15:        On Error Resume Next

  16:        Set objFSO = CreateObject("Scripting.FileSystemObject")

  17:        Set objStream = CreateObject("ADODB.Stream")

  18:        

  19:        If Err.Number = 0 Then

  20:            If objFSO.FileExists(fileName)  Then

  21:                objStream.Type = adTypeBinary

  22:                objStream.Open()

  23:                objStream.LoadFromFile(fileName)

  24:                objDocElem.dataType = "bin.base64"

  25:                objDocElem.nodeTypedValue = objStream.Read()

  26:                frmPageName.txtBase64Data.value = objDocElem.text                                   

  27:                objStream.Close()

  28:                'objFSO.DeleteFile fileName,true 'Delete the Image file if needed

  29:            Else

  30:                MsgBox("Could not find Image file " & fileName)

  31:            End If

  32:          Else

  33:              MsgBox("Your Browser Secuirty Settings currently do not allow image file reading.")

  34:          End If

  35:  

  36:        Set objXML = Nothing

  37:        Set objDocElem = Nothing

  38:        Set objStream = Nothing

  39:        Set objFSO = Nothing

  40:    End function

  41:  

  42:   </script>

 

Note: In order to make this example work you will need to make sure that following options are enabled in IE

1. Open IE and Go to Tools –> Internet Options –>Security Tab
2. Select Trusted Sites –> Sites
3. Type the website you are planning to run this page and click add and then Close.
4. Now Click on Custom Level button and make the following options are enabled in ActiveX controls and plug-ins

         a. Allow Previously unused ActiveX Controls to run …

         b. Automatic Prompting for ActiveX controls

         c. Binary and script behaviors

         d. Display video and  animation on a webpage that …

         e. Download signed ActiveX controls

         f. Download unsigned ActiveX controls

         g. Initialize and script ActiveX controls not marked as safe …

         h. Only allow approved domains to use ActiveX without …

          i. Run ActiveX controls and plug-ins

          j. Script ActiveX controls marked safe for scripting

 

5. Make sure following options are set to enabled in Miscellaneous section

         a. Access data sources across domains

         b. Allow META REFRESH

         c. Allow scripting of Microsoft web browser control

         d. Allow script-initiated windows without size or position …

6.  After making all the above changes, click on OK then Apply and then OK. Now Close the browser

 

Server Side Code

   1: Private Function ConvertImageFromBase64String() As Image

   2:         Dim NewImageFile As Image = Nothing

   3:         Try

   4:             Dim bytesData As Byte() = System.Convert.FromBase64String(txtBase64Data.Value)

   5:  

   6:             If bytesData.GetUpperBound(0) > 0 Then

   7:                 Using ImageStream As MemoryStream = New MemoryStream(bytesData)

   8:                     NewImageFile = Image.FromStream(ImageStream, True)

   9:                 End Using

  10:                 NewImageFile.Save(SERVER_PATH, System.Drawing.Imaging.ImageFormat.Bmp)

  11:             Else

  12:                 NewImageFile = Nothing

  13:             End If

  14:         Catch ex As Exception

  15:             NewImageFile = Nothing

  16:         End Try

  17:  

  18:         Return NewImageFile

  19:     End Function

 

Now Save or Present the image wherever you want.