关于vb.net中的Textbox问题求助

SengChuary

以下是关于Text两种用法，下面VB6的写法想写回vb.net用法怎么写，没搞懂请知道的同仁指点一二，谢谢

如果在多个文本中应用为空验证 应该加一个开关 以免产生多个同时验证
Dim tState As Boolean '开关
Private Sub Text1_GotFocus()'获取焦点时
tState = True
End Sub
Private Sub Text2_GotFocus()'获取焦点时
tState = True
End Sub
Private Sub Text1_LostFocus()'失去焦点时
If Text1.Text = "" And tState Then
MsgBox "该项不能为空"
Text1.SetFocus
End If
tState = False
End Sub
Private Sub Text2_LostFocus()
If Text2.Text = "" And tState Then
MsgBox "该项不能为空"
Text2.SetFocus
End If
tState = False
End Sub

另一种是vb6怎么写回vb.net的用法
Private Sub Text1_KeyPress(KeyAscii As Integer)
If KeyAscii = 13 Then
If Text1 = "" Then MsgBox "不能为空！": Text1.SetFocus
End If
End Sub
Private Sub Text1_LostFocus()
If Text1 = "" Then MsgBox "不能为空！": Text1.SetFocus
End Sub