参考

Dim dt As DataTable = DataTables("表A")
Dim cnt As Integer = dt.DataRows.Count
Dim ids(cnt - 1) As Integer
For i As Integer = 0 To cnt -1
    ids(i) = i
Next
For i As Integer = 0 To cnt \\ 2 \'洗牌次数
    Dim id1 As Integer = rand.Next(0,cnt)
    Dim id2 As Integer = rand.Next(0,cnt)
    Dim vid As Integer = ids(id1)
    ids(id1) = ids(id2)
    ids(id2) = vid
Next
dt.StopRedraw()
Dim cj As Integer = 1
Dim zc As Integer = 1
For i As Integer = 0 To ids.length -1
    dt.DataRows(ids(i))("场次") = cj
    dt.DataRows(ids(i))("座次") = zc
    If zc = 30 Then
        cj += 1
        zc = 0
    End If
    zc += 1
Next
dt.ResumeRedraw()