FileUpload error - "overload resolution failed because no 'new' is accessible"

Question

User1717218719 posted

I have the following code and recieve the error "overload resolution failed because no 'new' is accessible" on the line

Dim myFile As File = New File(contentType, originalName, fileData)

any help with why this is the case andd how to fix would be great.

    Protected Sub btnUpload_Click(ByVal sender As Object, ByVal e As EventArgs) 'Handles btnUpload.Click

        Dim FileUpload1 As FileUpload = TryCast(FindControl("FileUpload1"), FileUpload)
        If FileUpload1.HasFile Then
            Dim contentType As String = FileUpload1.PostedFile.ContentType
            Dim fileData As Byte() = New Byte(FileUpload1.PostedFile.InputStream.Length) {}
            FileUpload1.PostedFile.InputStream.Read(fileData, 0, fileData.Length)
            Dim originalName As String = Path.GetFileName(FileUpload1.PostedFile.FileName)
            Dim myFile As File = New File(contentType, originalName, fileData)
            'Select Case AppConfiguration.DataStoreType
            '    Case DataStoreType.Database
            '        myFile.Save()
            '        Exit Select
            '    Case DataStoreType.FileSystem
            '        myFile.Save(Server.MapPath(Path.Combine(AppConfiguration.UploadsFolder, myFile.FileUrl)))
            '        Exit Select
            'End Select
            Response.Redirect("~/")
        End If

    End Sub

Answer 1

User475983607 posted

The File class is static so you cannot "New" a the class.  Please see the official documentation.

https://docs.microsoft.com/en-us/dotnet/api/system.io.file?view=netframework-4.8

Are trying to save the file?

https://docs.microsoft.com/en-us/dotnet/api/system.io.file.writeallbytes?view=netframework-4.8

The file upload control is covered here which I think so interest you.

https://docs.microsoft.com/en-us/dotnet/api/system.web.ui.webcontrols.fileupload?view=netframework-4.8

VB.NET

https://forums.asp.net/t/1793792.aspx?Code+for+FileUpload+control+in+vb+net

Answer 2

User753101303 posted

Hi,

Or maybe you try to use a 3rd party class that would include as well its own File class and for now there is some confusion with https://docs.microsoft.com/en-us/dotnet/api/system.io.file?view=netframework-4.8 because the correct namespace is not in scope ?

Not sure form where you got this kind of code.

Answer 3

User1717218719 posted

Thanks for your reply!

I had a look at the links you provided and now understad that the File class is static so you cannot "New" a the class.

However I am still strugling to get my code to do what I want.

I am using a file upload and I want to get the content type, file data and original filename of the upload. once I have all of those I want to save It to my SQL database

Answer 4

User475983607 posted

I had a look at the links you provided and now understad that the File class is static so you cannot "New" a the class.

However I am still strugling to get my code to do what I want.

I am using a file upload and I want to get the content type, file data and original filename of the upload. once I have all of those I want to save It to my SQL database

What problem(s) are you trying to solve?  Are you having trouble getting the content type and file name?  Are you having trouble saving records in the database?  Are you receiving errors?  Have you made changes to the code?  

Answer 5

User1535942433 posted

Hi E.RU,

Accroding to your description,I guess you want to save files' content type,data and name into database.I suggest you could insert them using cmd.Parameters.AddWithValue.I create a demo for you.

More details,you could refer to below codes:

ASPX:

 <asp:FileUpload ID="FileUpload1" runat="server" />
            <asp:Button ID="btnUpload" runat="server" Text="Upload" OnClick="btnUpload_Click"/>
            <hr />
            <asp:Label ID="lblMessage" ForeColor="Green" runat="server" />

Code-behind:

    Protected Sub btnUpload_Click(sender As Object, e As EventArgs)
        Dim filename As String = Path.GetFileName(FileUpload1.PostedFile.FileName)
        Dim contentType As String = FileUpload1.PostedFile.ContentType
        Using fs As Stream = FileUpload1.PostedFile.InputStream
            Using br As New BinaryReader(fs)
                Dim bytes As Byte() = br.ReadBytes(CType(fs.Length, Integer))
                Dim constr As String = ConfigurationManager.ConnectionStrings("aspnet-TestApplicationWithDatabase-20190820030542").ConnectionString
                Using con As New SqlConnection(constr)
                    Dim query As String = "INSERT INTO tblFiles VALUES (@Name, @ContentType, @Data)"
                    Using cmd As New SqlCommand(query)
                        cmd.Connection = con
                        cmd.Parameters.Add("@Name", SqlDbType.VarChar).Value = filename
                        cmd.Parameters.Add("@ContentType", SqlDbType.VarChar).Value = contentType
                        cmd.Parameters.Add("@Data", SqlDbType.Binary).Value = bytes
                        con.Open()
                        cmd.ExecuteNonQuery()
                        con.Close()
                    End Using
                End Using
            End Using
        End Using

        lblMessage.Text = "File uploaded successfully."
    End Sub

Result：

Best regards,

Yijing Sun

Answer 6

User1717218719 posted

Thank you for your reply. this solves my problem of uploading to database. However I still want to upload to my Azure storage conainer. I am unsure how to do this dispite having tried and searched many examples any help would be great.

Here is code I tried which does not work. I dont recieve errors but nothing happens. Not sure if I am on the right track.

    Dim StorageConnStr As String = "(connection string)"
    Dim containerName As String = "test"
    Dim container As CloudBlobContainer
    Private gdvContainer As Object

    '--CREATE CONTAINER
    Private Async Function CreateContainer(ByVal cancelToken As CancellationToken) As Task
        Try
            Dim storAcc As CloudStorageAccount = CloudStorageAccount.Parse(StorageConnStr)
            Dim blobClient As CloudBlobClient = storAcc.CreateCloudBlobClient()
            container = blobClient.GetContainerReference(containerName)
            Await container.CreateIfNotExistsAsync(cancelToken)

            Dim blobContPermission As New BlobContainerPermissions()
            blobContPermission.PublicAccess = BlobContainerPublicAccessType.Container

            container.SetPermissions(blobContPermission)
        Catch ex As OperationCanceledException
            Throw New OperationCanceledException("Create container canceled")
        End Try
    End Function

    '--UPLOAD TO AZURE
    Public Async Function UploadAsync(ByVal path As String, ByVal cancelToken As CancellationToken) As Task

        Try
            Await CreateContainer(cancelToken)

            Dim blockBlob As CloudBlockBlob = container.GetBlockBlobReference(System.IO.Path.GetFileName(path))

            Await blockBlob.UploadFromFileAsync(path, cancelToken)

        Catch ex As OperationCanceledException
            Throw New OperationCanceledException("UploadAsync canceled")
        End Try
    End Function


    Protected Async Sub BtnSave_Click(sender As Object, e As EventArgs) 'Handles BtnSave.Click

        Dim StorageConnStr As String = "(Connection String)"
        Dim cancelToken As CancellationToken
        Dim appSettings As Object = ConfigurationManager.AppSettings

        Dim AZBlob As Object = (appSettings(StorageConnStr) & containerName)
        'Dim AZBlob As New AzureBlob(ConfigurationManager.AppSettings(StorageConnectionString), mycontainer)
        '-------

        Dim FileUpload1 As FileUpload = TryCast(FindControl("FileUpload1"), FileUpload)
        If FileUpload1.HasFile Then
            Dim contentType As String = FileUpload1.PostedFile.ContentType
            Dim fileData As Byte() = New Byte(FileUpload1.PostedFile.InputStream.Length) {}
            FileUpload1.PostedFile.InputStream.Read(fileData, 0, fileData.Length)
            Dim originalName As String = Path.GetFileName(FileUpload1.PostedFile.FileName)
            Dim myFile As File = New File(contentType, originalName, fileData)

            Await AZBlob.UploadAsync(originalName, cancelToken)
          
        End If
    End Sub