如何将输入框限制为 vb 中的 11 个数值

Question

如何在 vb 中将输入框限制为 11 个数值？我想让一个人能够编辑 phone 号码，但我当前的代码似乎有问题。

 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

您可以使用正则表达式来检查：

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

您的代码可以如下所示：

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 InputBox 中删除 CInt，因为如果 [=15] 中的值，代码会抛出 Exception =] 不是有效的整数。使用该解决方案的正则表达式，只能将数字写入 InputBox.

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

how can i limit inputbox to 11 numerical values in vb

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