Map Virtual path to physical path - vb.net

Question

I have an issue with the method Server.MapPath.
I am currently using the method HttpContext.Current.Server.MapPath("MyPath") to obtain the physical path of "MyPath" in an ApiController, get method.
If I try to use the same method in an ApiController which returns an HttpResponse, it gives the error:
Current is not a member of System.Net.Http.HttpContent
How can I use the method Server.MapPath in the context of an HttpResponseMessage?
(I am working in Visual Basic)
Edit: I am using it like this:
<HttpGet>
Public Function MyFunc() As HttpResponseMessage
Try
Dim streamContent = New PushStreamContent(_
Function(outputStream, httpContext, transportContent)
Try
Dim lPath = httpContext.Current.Server.MapPath(MyPath)
.... some code
End Try
End Function)
Dim lResult = New HttpResponseMessage(HttpStatusCode.OK)
lResult.Content = streamContent
Return lResult
End Try
End Function

Answer 1

The second argument passed to your callback function is of type HttpContent. You're effectively hiding HttpContext inside your lambda because you're named that parameter HttpContext. Try:
Dim streamContent = New PushStreamContent(_
Function(outputStream, content, transportContent) 'Renamed parameter here
Try
Dim lPath = HttpContext.Current.Server.MapPath(MyPath)
'.... some code
Catch ex As Exception
Finally
outputStream.Close()
End Try
End Function)
The PushStreamContent constructor definition is:
Public Sub New ( _
onStreamAvailable As Action(Of Stream, HttpContent, TransportContext) _
)