Question

如何在vb中将输入框限制为11个数值？我想让一个人编辑一个电话号码，但似乎对我当前的代码有疑问。

 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    For Each x As ListViewItem In lvCustomers.Items
        Dim contactEdit As String
        If x.Checked Then
            contactEdit = CInt(InputBox("Modify contact no."))
            Do Until contactEdit.Count = 11
                MessageBox.Show("Maximum numerical digits of 11")
            Loop

            x.SubItems(5).Text = contactEdit

            x.Checked = False

        End If
    Next
End Sub

Answer 1

您可以使用Regex来检查：

Imports System.Text.RegularExpressions
'[...]
Dim isValid As Boolean = Regex.Match("12345", "^\d{0,11}$").Success()

您的代码可能如下所示：

Imports System.Text.RegularExpressions
'[...]
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    For Each x As ListViewItem In lvCustomers.Items
        Dim contactEdit As String

        If x.Checked Then
            contactEdit = InputBox("Modify contact no.")

            Do Until Regex.Match(contactEdit, "^\d{0,11}$").Success()
                MessageBox.Show("Maximum numerical digits of 11")
                contactEdit = InputBox("Modify contact no.")
            Loop

            x.SubItems(5).Text = contactEdit
            x.Checked = False
        End If
    Next
End Sub

您可以在RegExp（{minValue,maxValue}）上定义输入的最小和最大长度。输入必须是数字（\d）。您可以在此站点上找到所用RegExp的说明：https://regex101.com/r/6h7z2u/1

提示：我建议从CInt移除InputBox，因为如果Exception的值不是InputBox，代码会抛出InputBox一个有效的整数。使用解决方案的RegExp，只能将数字写入import React from 'react'; import { connect } from 'react-redux'; import { showDropdown } from '../../redux/actions/dropdownActions'; function StreamWidget(props) { const onClickHandler = () => props.showDropdown() return ( <div> <a href='#' role='button' onClick={ onClickHandler } /> </div> ); } export default connect(null, { showDropdown })(StreamWidget);。

Answer 2

您可以使用 Len（contactEdit.Text）= 11 而不是 contactEdit.Count = 11

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    For Each x As ListViewItem In lvCustomers.Items
        Dim contactEdit As String
        If x.Checked Then
            contactEdit = CInt(InputBox("Modify contact no."))
            Do Until Len(contactEdit.Text) >= 11
                MessageBox.Show("Maximum numerical digits of 11")
            Loop
            x.SubItems(5).Text = contactEdit
            x.Checked = False
        End If
    Next
End Sub

如何将输入框限制为vb中的11个数值

2 个答案: