用 22 个单位和 3 个小数点限制文本

如何解决用 22 个单位和 3 个小数点限制文本

如何限制文本框的输入，使其仅接受 22 个单位和 3 个小数点？

解决方法

看看这个，只有数字和逗号。

当离开另一个文本框时，它会删除超过 22 个，当超过 1 个逗号时，它会删除并将数字返回到逗号后面的 3 个数字。

这是超过 22 个和超过 1 个逗号 1234,56789,123,45699999

将文本框留给按钮或其他文本框，它将返回此 1234567891234569,999

 Private Sub TextBox1_TextChanged(sender As Object,e As EventArgs) Handles TextBox1.TextChanged
    Dim a_chars As String = "0123456789,",t_tekst As String,i As Integer
    For i = 1 To Len(TextBox1.Text)
        If InStr(a_chars,Mid(TextBox1.Text,i,1)) = 0 Then
            MsgBox("Only numbers and comma")
        Else
            t_tekst = t_tekst & Mid(TextBox1.Text,1)
        End If
    Next
    TextBox1.Text = t_tekst
    TextBox1.SelectionStart = i
End Sub

Private Sub TextBox1_Validating(sender As Object,e As CancelEventArgs) Handles TextBox1.Validating

    If TextBox1.TextLength > 22 Then
        TextBox1.Text = TextBox1.Text.Substring(0,22)
        MsgBox("More then 22 .")
        TextBox1.Focus()
    End If
    Dim t_tekst As String,d_sep As Boolean,c_placed As Boolean,lgt As Integer

    If TextBox1.Text = "" Then Exit Sub

    d_sep = False
    lgt = Len(TextBox1.Text)
    t_tekst = vbNullString

    For i As Integer = 1 To lgt
        Select Case Mid(TextBox1.Text,1)
            Case ".","
                d_sep = True
            Case Else
                If i >= lgt - 2 Then
                    If d_sep And Not c_placed Then
                        t_tekst = t_tekst & ","
                        c_placed = True
                    End If
                End If
                t_tekst = t_tekst & Mid(TextBox1.Text,1)
        End Select
    Next
    TextBox1.Text = t_tekst

End Sub