VB.net, cannot access OpenFileDialog that has been added to project

Question

I have decades of experience writing VB6 apps but today I tried to write a simple VB.net app using Microsoft Visual Studio 2019. I fell at the first hurdle. I'm sure I'm doing something really simple wrong so forgive the naive question.

Using the toolbox, I added an OpenFileDialog object to my main (one and only) form. Unlike VB6, this didn't appear on the form but in a sort of bar along the bottom of the window, but it was definitely there and I was able to set some properties.

I then added a button and wrote my first line of code: With OpenFileDialog1 Wrong: I get errpr BC30451. 'OpenFileDialog1' is not declared. It may be inaccessible due to its protection level.

But I can see it sitting there in the design view, I have spelt its name correctly and the above code is exactly copied from the example. I tried changing OpenFileDialog1's Modifiers property from Friend to Public - makes no difference.

What novice mistake have I made? How do I access an OpenFileDialog object that I have definitely added to my form?

Answer 1

The FolderBrowserDialog which can be dragged onto the form using the toolbox, is out of date and offers (from today's perspective) too few options. Do yourself a favor and use the Nuget Package Manager to download the modern OpenFileDialog.

Imports Microsoft.WindowsAPICodePack.Dialogs

in your Private Sub Button1_Click :

Dim Pfad As String
        Using OFD1 As New CommonOpenFileDialog
            OFD1.Title = "Datei auswählen"
            OFD1.Filters.Add(New CommonFileDialogFilter("JPG", ".jpg"))
            OFD1.Filters.Add(New CommonFileDialogFilter("JPEG", ".jpeg"))
            OFD1.Filters.Add(New CommonFileDialogFilter("Bitmap", ".bmp"))
            OFD1.Filters.Add(New CommonFileDialogFilter("PNG", ".png"))
            OFD1.IsFolderPicker = False 'true to make it an FolderBrowserDialog ;-)
            OFD1.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
            If OFD1.ShowDialog = CommonFileDialogResult.Ok Then
                Pfad = OFD1.FileName
            Else
                Return
            End If
        End Using

for Multiselect (with Bildpfade1 as a New List(of String) ):

Using OFD As New CommonOpenFileDialog
            OFD.Title = "Bilder auswählen"
            OFD.Filters.Add(New CommonFileDialogFilter("JPG", ".jpg;jpeg"))
            OFD.Multiselect = True
            OFD.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
            If OFD.ShowDialog() = CommonFileDialogResult.Ok Then
                For Each file As String In OFD.FileNames
                    Bildpfade1.Add(file)
                Next
            End If
End Using

Answer 2

I think I have found the answer but it looks, to me, like a bug in Visual Studio. I saved the project and closed Visual Studio. Restarted and reloaded the project. All the controls I had added to my form had vanished!

I rebuilt the now-empty project then started adding controls - lo and behold, I can now access all my controls from code whereas, previously, I couldn't access any of them. It looks like, prior to the initial build, none of the controls I thought I'd added had actually been added. Certainly they didn't survive save project, restart Visual Studio.

Seems to work now. Many thanks to those who contributed suggestions.