Question

我尝试从表单中的用户输入验证邮政编码。使用这个课程，我试图搜索每个角色并检查它。然后在我使用后一个代码的表单中调用。我遇到的问题是弹出一个错误

＆＃34;从字符串转换＆＃34; True0＆＃34;输入＆＃39; Double＆＃39;无效。＆＃34;

Function VaidatePostCode(ByVal Post As String) As String


    For C = 0 To Len(Post) - 1



        If Char.IsLetter(Post(C)) & C = 0 Then
            _boolvalid = True
        Else
            _boolvalid = False
        End If


        If Char.IsLetter(Post(C)) & C = 1 Then
            _boolvalid = True
        Else
            _boolvalid = False
        End If



        If Char.IsNumber(Post(C)) & C = 2 Then
            _boolvalid = True

        Else


            _boolvalid = False
        End If



        If Char.IsWhiteSpace(Post(C)) & C = 3 Then
            _boolvalid = True



        Else


            _boolvalid = False

        End If


        If Char.IsNumber(Post(C)) & C = 4 Then
            _boolvalid = True

        Else


            _boolvalid = False
        End If


        If Char.IsLetter(Post(C)) & C = 5 Then
            _boolvalid = True

        Else
            _boolvalid = False

        End If


        If Char.IsLetter(Post(C)) & C = 6 Then
            _boolvalid = True

        Else
            _boolvalid = False

        End If

    Next C


    Return _boolvalid
End Function

这是VB.NET表单中的代码

 Private Sub txtPost_Validated(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtPost.Validated
    If myVal.VaidatePostCode(txtPost.Text) = False Then
        MsgBox("Please enter correct data format into postcode")
    End If


End Sub

Answer 1

要检查值是否为数字，您可以像这样使用Integer.TryParse：

If Not Integer.TryParse(txtPost.Text, intTemp) Then
    MsgBox ...

如何在VB.NET中验证邮政编码？

1 个答案: