My WPF application gets a file from the user with Microsoft.Win32.OpenFileDialog()...
Private Sub ButtonUpload_Click(...)
Dim FileOpenStream As Stream = Nothing
Dim FileBox As New Microsoft.Win32.OpenFileDialog()
FileBox.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments)
FileBox.Filter = "Pictures (*.jpg;*.jpeg;*.gif;*.png)|*.jpg;*.jpeg;*.gif;*.png|" & _
"Documents (*.pdf;*.doc;*.docx;)|*.pdf;*.doc;*.docx;|" & _
"All Files (*.*)|*.*"
FileBox.FilterIndex = 1
FileBox.Multiselect = False
Dim FileSelected As Nullable(Of Boolean) = FileBox.ShowDialog(Me)
If FileSelected IsNot Nothing AndAlso FileSelected.Value = True Then
Try
FileOpenStream = FileBox.OpenFile()
If (FileOpenStream IsNot Nothing) Then
Dim ByteArray As Byte()
Using br As New BinaryReader(FileOpenStream)
ByteArray = br.ReadBytes(FileOpenStream.Length)
End Using
Dim z As New ZackFile
z.Id = Guid.NewGuid
z.FileData = ByteArray
z.FileSize = CInt(ByteArray.Length)
z.FileName = FileBox.FileName.Split("\").Last
z.DateAdded = Now
db.AddToZackFile(z)
db.SaveChanges()
End If
Catch Ex As Exception
MessageBox.Show("Cannot read file from disk. " & Ex.Message, "Fail", MessageBoxButton.OK, MessageBoxImage.Error)
Finally
If (FileOpenStream IsNot Nothing) Then
FileOpenStream.Close()
End If
End Try
End If
End Sub
And my ASP.NET MVC application serves it up for download at a web site with FileStreamResult()...
Public Class ZackFileController
Inherits System.Web.Mvc.Controller
Function Display(ByVal id As Guid) As FileStreamResult
Dim db As New EfrDotOrgEntities
Dim Model As ZackFile = (From z As ZackFile In db.ZackFile _
Where z.Id = id _
Select z).First
Dim ByteArray As Byte() = Model.ImageData
Dim FileStream As System.IO.MemoryStream = New System.IO.MemoryStream(ByteArray)
Dim ContentType As String = ?????
Dim f As New FileStreamResult(FileStream, ContentType)
f.FileDownloadName = Model.FileName
Return f
End Function
End Class
But FileStreamResult() needs a content type string. How do I know the correct content type of my file?