VB Express 2010 Hundreds of Pictures chosen randomly

[Groer]

I want to be able to randomly choose a picture of a student from hundreds of possible ones and display it in a picture box.
Using "Select Case intRndStudent" works fine when tested for 14 students

   Select Case intRndStudent
            Case 1
                picStudent.Image = My.Resources.1
            Case 2
                picStudent.Image = My.Resources.2

but the code will be incredibly long and adding another picture is a chore

I want to use a variable but I can't get it to work.

        intRndStudent = Int(Rnd() * intNumPics) + 1 ' choose a picture at random
        txtOutput.Text = intRndStudent ' used to check that random number is being chosen correctly

        picStudent.Image = My.Resources.intRndStudent ' this code is bad - Error	1	'intRndStudent' is not a member of 'Resources'.

Would someone please tell me why this does not work and how to make it work?

[vbfbryce]

In my case, I have only three resource images. This code will add each of them to a list of images, which can then be loaded into a picturebox via a random number generator. See if you can adapt to your needs:

Public Class Form1

    Dim picList As New List(Of Image)

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Dim dEntry As DictionaryEntry
        Dim rSet As Resources.ResourceSet = My.Resources.ResourceManager.GetResourceSet _
                                        (Globalization.CultureInfo.CurrentCulture, True, True)

        For Each dEntry In rSet.OfType(Of Object)()
            If TypeOf (dEntry.Value) Is System.Drawing.Image Then
                picList.Add(dEntry.Value)
                picList(picList.Count - 1).Tag = dEntry.Key
            End If
        Next
    End Sub

    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim r As Random = New Random
        Dim num As Integer
        Dim lowerBound As Integer
        Dim upperBound As Integer

        lowerBound = 0
        upperBound = 2

        num = r.Next(lowerBound, upperBound + 1)    'results in a number between 0 and 2, inclusive
        PictureBox1.Image = picList(num)
    End Sub
End Class

[techgnome]

If you're going to have mroe than just a few that you're going to choose from, then you might be better off putting the files into a folder, not as a resource... then you can use io.directory.getallfiles to get a list of the files... then create a random (note - use the random class, not the older rnd function) number between 0 and the array count (less 1 of course) to get the file name... once you have that, it's a simple matter to load it and badda bing badda boom.

-tg

[dday9]

I completely agree with TG on using a folder to hold all of the files. If nothing else, having hundreds of pictures in your resources will make your application look bloated. Here is an example of doing exactly what TG said:

Private images As New List(Of Bitmap)
Private r As New Random
Private Sub MyForm_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load

    Dim files() As String = Io.Directory.GetAllFiles("MyPath/MyImageFolder")

    For Each img As String In files
        images.Add(New Bitmap(img))
    Next

End Sub

Private Function GetRandomImage() As Bitmap
    Return images.Item(r.Next(0, images.Count))
End Function

[Groer]

Thankyou for your replies. I will have another go this evening and get back if I need further pointers.

[Groer]

Dim files() As String = Io.Directory.GetAllFiles("MyPath/MyImageFolder")

VB tells me
'GetAllFiles' is not a member of 'System.IO.Directory'

Can you tell me why?

[techgnome]

because it's GetFiles I was shooting from the hip from a system that didn't have VS.

FYI - any time you encounter something new from the framework... if you google "MSDN {term here}" 90% of the time you'll get the documentation for it right up front. In this case "MSDN GetAllFile" brings up "Did you mean 'GetFiles'?" and a bunch of links to the documentation for Directory.GetFiles. The first of which is the one I linked to above.

-tg