Question

Vb中我用textbox的change事件判断每个字节输入的类型，如不符合条件则提示

。例如，长度设为5个字符串，第三个字符设为数字，如果输非数字则提示。到这里，我怎么实现输入的非数字自动清除，让我重新输入，而不是我手动删除。
只是要删除刚输入的第三字符，前面正确的不删除。不是要重获整个textbox的焦点，求高手惠予指教。

Answer 1

Private Sub Text1_Change()
If IsNumeric(Mid(Text1.Text, 3, 1)) = True Then
Text1.Text = Replace(Text1.Text, Mid(Text1.Text, 3, 1), "")
Text1.SelStart = Len(Text1.Text)
End If
End Sub

'或者可以在按数字键时
Private Sub Text1_KeyPress(KeyAscii As Integer)
If KeyAscii > 47 And KeyAscii < 59 Then KeyAscii = 0
End Sub

追问

我要怎么做才能在msgbox提示后，错误字节自动清除并重获光标焦点，如上代码，若case2输入不对如何清除输入，又保留前面的case1输入的内容保留

追答

Dim Txte1 As String, Txte2 As String, cs
Private Sub Form_Load()
Txte1 = ""
Txte2 = Text1.Text
End Sub
Private Sub Form_Click()
MsgBox Txte2 & vbCrLf & "保留的非数字是" & Mid(Txte2, 3, 1), vbOKOnly, "Text1.Change后,如果第三个不是数字就保留最新的"
Text1.SelStart = 1
End Sub
Private Sub Text1_Change()
If IsNumeric(Mid(Text1.Text, 3, 1)) = False And Text1.SelStart = 3 Then
Txte1 = Text1.Text '错啦,case1、case2是什么,用不着吧。
Text1.Text = Replace(Text1.Text, Mid(Text1.Text, 3, 1), "", 1, 1)
Text1.SelStart = Len(Text1.Text)
MsgBox "输了非数字" & vbCrLf & "刚输入的字符已保留,若要查看单击窗体", vbOKOnly, "提示"
Txte2 = Replace(Text1.Text, Left(Text1.Text, 2), Left(Txte1, 3))
End If
Select Case cs
Case "tenet"
Case "digital"
End Select
End Sub

追问

Textbox change事件中 a=text1.text N=len(trim(text1.text) Str=mid(trim(text1.text),n,1) H=ascb (str) Select case n Case 1 If( h >48)or (h45then Msgbox"",,"" Case is<6 If h后面的代码高手都了解了。我的问题是当我输入第n个字符时，如果条件不符，怎么让输入的字符自动清除掉，并重获这第n个字符位置的输入焦点。

追答

Dim conser, 数字 As Boolean, Oldption, Newn, cur
Private Sub Form_Click()
MsgBox Newoption & vbCrLf & "第" & Str(cur+1) & "字符", vbOKOnly, Oldption
End Sub
Private Sub Text1_KeyDown(KeyCode As Integer, Shift As Integer)
cur=Text1.SelStart
Oldption = Text1.Text
End Sub
Private Sub Text1_KeyUp(KeyCode As Integer, Shift As Integer)
Newn=Text1.Text
On Error Resume Next
If IsNumeric(Mid(Newn,cur+1,1)) =False Then
If 数字 = False Then
If KeyCode = vbKeySpace Or KeyCode = 13 Then
If Not KeyCode = 16 And conser = 5 Then
MsgBox "输了非数字" & vbCrLf & "刚输入的字符已保留,若要查看单击窗体", vbOKOnly, "提示"
conser = 0
End If
Text1.Text = Oldption '& CStr(Val(Newn))
Text1.SelStart= cur
End If
End If
If 数字 = True And conser = 5 Then
MsgBox "输了非数字" & vbCrLf & "刚输入的字符已保留", vbOKOnly, "提示"
Text1.Text = Oldption
Text1.SelStart=cur
conser = 0
End If
End If
End Sub
Private Sub Text1_Change()
conser = 5
If Len(Text1.Text) <= Len(Oldption) Then
数字 = False
Else
数字 = True
End If
End Sub