List view control is blank

Private Sub populate_studentLvw()
        studentLvw.View = View.Details
        studentLvw.GridLines = True
        studentLvw.FullRowSelect = True

// Add your columns here.
        
       studentLvw.Columns.Add("Col1")
        studentLvw.Columns.Add("Col2")
        studentLvw.Columns.Add("Col3")
        studentLvw.Columns.Add("Col4")
       
 
        cmd = New SqlCommand("select * FROM Students", con)
        Using dr As SqlDataReader = cmd.ExecuteReader
            While dr.Read
                Dim li As New ListViewItem()
                li.Text = Convert.ToString(dr.Item("student_pk"))
                li.SubItems.Add(Convert.ToString(dr.Item("student_fullname")))
                li.SubItems.Add(Convert.ToString(dr.Item("student_branch")))
                li.SubItems.Add(Convert.ToString(dr.Item("student_scholarship")))
                studentLvw.Items.Add(li)
            End While
        End Using
        cmd.Dispose()
        con.Close()
    End Sub