How to upload file with Asp.net Web Api project? - vb.net

Question

i have a web API project to be consumed from mobile applications and i was trying to make a file upload controller. there are few resources in C# and i don't find anything useful for VB.NET.
i tried this code below converting from c# to VB.NET, but says "Move is not a member of MultiPartFileData".
Imports System
Imports System.Collections.Generic
Imports System.IO
Imports System.Linq
Imports System.Net
Imports System.Net.Http
Imports System.Threading.Tasks
Imports System.Web
Imports System.Web.Http
Namespace HelloWorld.Controller
Public Class FileUploadingController
Inherits ApiController
<HttpPost>
<Route("api/FileUploading/UploadFile")>
Public Async Function UploadFile() As Task(Of String)
Dim ctx = HttpContext.Current
Dim root = ctx.Server.MapPath("~/App_Data")
Dim provider = New MultipartFormDataStreamProvider(root)
Try
Await Request.Content.ReadAsMultipartAsync(provider)
For Each file In provider.FileData
Dim name = file.Headers.ContentDisposition.FileName
name = name.Trim(""""c)
Dim localFileName = file.LocalFileName
Dim filePath = Path.Combine(root, name)
File.Move(localFileName, filePath)
Next
Catch e As Exception
Return $"Error: {e.Message}"
End Try
Return "File uploaded!"
End Function
End Class
End Namespace

Answer 1

That error message means the compiler think that you are trying to call a method from the MultiPartFileData class. The variable of type MultiPartFileData is the one called file (notice the lowercase) initialized in the For Each loop.
Instead you want to call the Move method from the System.IO.File class (notice the uppercase).
VB.NET services (always running in background looking to catch errors while you type) is case insensitive so, for it, the two names are the same and here arises the error emitted when you code that line.
The best solution is to avoid names like file for your variables when you plan to use the class System.IO.File. Otherwise you could simply add the full qualified method's name in this way
System.IO.File.Move(localFileName, filePath)