vb如何用二重循环打出如下图形 1 12 123 1234 12345

Function GetStr(ByVal i As Integer) As String '取得字符串
If i = 1 Then
GetStr = 1
Else
GetStr = GetStr(i - 1) & i
End If
End Function
Private Sub Command1_Click() '调用输出
Me.AutoRedraw = True
Dim n As Integer
n = Val(InputBox("请输入一个大于0的数值", "输入"))
If n > 0 Then
For i = 1 To n
Print GetStr(i)
Next
Else
MsgBox "输入的数值无效"
End If
End Su