在vb.net中向groupbox动态添加标签和其他控件不起作用?

出于某种原因,程序只在其中放置了一个标签,而其他标签似乎不可见,即使它们已经创建(我使用了messagebox进行检查)。有人能帮我把它们放进去吗,因为我对编程相当陌生,需要帮助。

代码:

'sets up Labels for editing materials
    prgFunctions.loadMat()
    Dim counter As Integer

    Dim newMatIDLabel(numMatFile) As Label
    Dim newMatRdb(numMatFile) As RadioButton
    Dim lastPos As Integer

    'testing to see if materials load GET RID OF LATER
    '  For counter = 1 To numMatFile
    'ListBox1.Items.Add(materials(counter).matName)
    '  Next

    'create the labels with information
    For counter = 1 To numMatFile
        'ID
        newMatIDLabel(counter) = New Label
        newMatIDLabel(counter).Name = "lblMatIDNum" & counter
        newMatIDLabel(counter).Text = materials(counter).matID
        newMatIDLabel(counter).Parent = gbxMaterials


        ' MsgBox(newMatIDLabel(counter).Name & "  " & newMatIDLabel(counter).Text)
    Next

    'create the checkboxes NOW RADIO BUTTONS
    For counter = 1 To numMatFile
        newMatRdb(counter) = New RadioButton
        newMatRdb(counter).Name = "chkMatSelectNum" & counter
        newMatRdb(counter).Text = ""
        newMatRdb(counter).Parent = gbxMaterials
    Next

    'matID locations
    lastPos = 10
    For counter = 1 To numMatFile
        'SOMEHOW MOVE IT INTO THE GROUPBOX INSTEAD, as issues arise everywhere
        newMatIDLabel(counter).Location = New Point(7, lastPos + 10)

        lastPos = lastPos + 10
    Next