VB中如何将String中的数字与字母提取出来？

[hotjo110]

VB中如何将String中的数字与字母提取出来？ 用function来做，必须包含while。

Private Function changeToUp(ByVal inputdata) As String
        Dim input As String
        inputdata = txtTest.Text.Trim
        If inputdata.Length <= 0 Then                                     
            input = "Note :Please enter a string with letters or digits"
        Else
            'convert string's letters to upper case
            input = inputdata.ToUpper

            Dim intLastPos = input.Length - 1
            Dim intPos As Integer = 0
            Do

                Dim chrVar As Char = input.Chars(intPos)
                If chrVar >= "A" And chrVar <= "Z" Then
                    inputdata = input & chrVar
 ElseIf input(intPos).ToString.Equals("0") Then
                    inputdata = inputdata & "0"
                ElseIf input(intPos).ToString.Equals("1") Then
                    inputdata = inputdata & "1"
                ElseIf input(intPos).ToString.Equals("2") Then
                    inputdata = inputdata & "2"
                ElseIf input(intPos).ToString.Equals("3") Then
                    inputdata = inputdata & "3"
                ElseIf input(intPos).ToString.Equals("4") Then
                    inputdata = inputdata & "4"
                ElseIf input(intPos).ToString.Equals("5") Then
                    inputdata = inputdata & "5"
                ElseIf input(intPos).ToString.Equals("6") Then
                    inputdata = inputdata & "6"
                ElseIf input(intPos).ToString.Equals("7") Then
                    inputdata = inputdata & "7"
                ElseIf input(intPos).ToString.Equals("8") Then
                    inputdata = inputdata & "8"
                ElseIf input(intPos).ToString.Equals("9") Then
                    inputdata = inputdata & "9"

                Else
                End If
                intPos += 1
            Loop Until intPos >= intLastPos


        End If
        Return inputdata
    End Function

这样的取值当输入标点符号的时候，产生问题。

[hotjo110]

Public Class FormPalindromeRecognizer

    Private Sub btnClear_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnClear.Click
        txtTest.Text = String.Empty
        lblAbout.Text = String.Empty
        txtTest.ReadOnly = False

        btnClear.Enabled = False
        btnTest.Enabled = True

        txtTest.Focus()
    End Sub
    Private Function changeToUp(ByVal inputdata) As String
        Dim input As String
        inputdata = txtTest.Text.Trim
        If inputdata.Length <= 0 Then                                      'Try statements
            input = "Note :Please enter a string with letters or digits"
        Else
            'convert string's letters to upper case
            input = inputdata.ToUpper

            Dim intLastPos = input.Length - 1
            Dim intPos As Integer = 0
            Do

                Dim chrVar As Char = input.Chars(intPos)
                If chrVar >= "A" And chrVar <= "Z" Then
                    inputdata = input & chrVar

                    'ElseIf Int(input(intPos)) >= 0 And Int(input(intPos)) <= 9 Then
                    '    input = input & Int(input(intPos))
                    'End If
                ElseIf input(intPos).ToString.Equals("0") Then
                    inputdata = inputdata & "0"
                ElseIf input(intPos).ToString.Equals("1") Then
                    inputdata = inputdata & "1"
                ElseIf input(intPos).ToString.Equals("2") Then
                    inputdata = inputdata & "2"
                ElseIf input(intPos).ToString.Equals("3") Then
                    inputdata = inputdata & "3"
                ElseIf input(intPos).ToString.Equals("4") Then
                    inputdata = inputdata & "4"
                ElseIf input(intPos).ToString.Equals("5") Then
                    inputdata = inputdata & "5"
                ElseIf input(intPos).ToString.Equals("6") Then
                    inputdata = inputdata & "6"
                ElseIf input(intPos).ToString.Equals("7") Then
                    inputdata = inputdata & "7"
                ElseIf input(intPos).ToString.Equals("8") Then
                    inputdata = inputdata & "8"
                ElseIf input(intPos).ToString.Equals("9") Then
                    inputdata = inputdata & "9"

                Else
                End If
                intPos += 1
            Loop Until intPos >= intLastPos


        End If
        Return inputdata
    End Function

    Private Sub btnTest_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnTest.Click
        Dim strAbout As String = String.Empty
        Dim strTest As String
        Dim strEdited As String
        Dim intLastPos As Integer
        'input

        'strTest = changeToUp(txtTest.Text)

        'strEdited = strTest
        'If strTest.Length <= 0 Then                                      'Try statements
        '    strAbout = "Please enter a string with some letters"
        'Else
        '    'convert string's letters to upper case
        '    strTest = strTest.ToUpper
        'Try



        strEdited = changeToUp(txtTest.Text)

        ' strEdited = strTest
        'strTest = txtTest.Text
        'strTest = strTest.Trim
        'strTest = strTest.ToUpper
        'strEdited = String.Empty
        ' intLastPos = strTest.Length - 1


        'strEdited = filterOutLettle(strEdited)
        'For intPos As Integer = 0 To intLastPos
        '    Dim chrVar As Char = strTest.Chars(intPos)
        '    If chrVar >= "A" And chrVar <= "Z" Then
        '        strEdited = strEdited & chrVar

        '    ElseIf (Int(strTest(intPos).ToString) >= 0) And (Int(strTest(intPos).ToString) <= 9) Then
        '        strEdited = strEdited & strTest(intPos).ToString
        '    Else

        '    End If
        ' Next
        'ElseIf strEdited(intPos).ToString.Equals("0") Then
        '    strEdited = strEdited & "0"
        'ElseIf strEdited(intPos).ToString.Equals("1") Then
        '    strEdited = strEdited & "1"
        'ElseIf strEdited(intPos).ToString.Equals("2") Then
        '    strEdited = strEdited & "2"
        'ElseIf strEdited(intPos).ToString.Equals("3") Then
        '    strEdited = strEdited & "3"
        'ElseIf strEdited(intPos).ToString.Equals("4") Then
        '    strEdited = strEdited & "4"
        'ElseIf strEdited(intPos).ToString.Equals("5") Then
        '    strEdited = strEdited & "5"
        'ElseIf strEdited(intPos).ToString.Equals("6") Then
        '    strEdited = strEdited & "6"
        'ElseIf strEdited(intPos).ToString.Equals("7") Then
        '    strEdited = strEdited & "7"
        'ElseIf strEdited(intPos).ToString.Equals("8") Then
        '    strEdited = strEdited & "8"
        'ElseIf strEdited(intPos).ToString.Equals("9") Then
        '    strEdited = strEdited & "9"

        'Else


        'Catch ex As FormatException
        'strAbout = "Please enter a string with some letters~~~!"
        ' End Try


        'filter out non-alphabetic characters
        'Dim strEdited As String = String.Empty
        ' strEdited = filterOutLettle(strTest.Length - 1)
        'Dim intLastPos As Integer = strTest.Length - 1
        'For intPos As Integer = 0 To intLastPos
        '    Dim chrVar As Char = strTest.Chars(intPos)
        '    If chrVar >= "A" And chrVar <= "Z" Then
        '        strEdited = strEdited & chrVar
        '    End If
        'Next



        If strEdited.Length <= 0 Then
            strAbout = "Please enter a string that contains letters or digits."
        Else
            'build reversed - the reverse of edited string


            Dim strReversed As String = String.Empty
            intLastPos = strEdited.Length - 1
            For intPos As Integer = 0 To intLastPos
                Dim chrVar As Char = strEdited.Chars(intPos)
                strReversed = chrVar & strReversed
            Next

            If strEdited = strReversed Then
                strAbout = "It is a palindrome"
            Else
                strAbout = "It is not a palindrome"
            End If
        End If
        'End If

        lblAbout.Text = strAbout
        txtTest.ReadOnly = True
        btnClear.Enabled = True

        btnTest.Enabled = False
    End Sub
    'Private Function filterOutLettle(ByVal enterdata As String) As String


    '    Dim intLastPos = enterdata.Length - 1
    '    For intPos As Integer = 0 To intLastPos
    '        Dim chrVar As Char = enterdata.Chars(intPos)
    '        If chrVar >= "A" And chrVar <= "Z" Then
    '            enterdata = enterdata & chrVar

    '        ElseIf (Int(enterdata(intPos).ToString) >= 0) And (Int(enterdata(intPos).ToString) <= 9) Then
    '            enterdata = enterdata & enterdata(intPos).ToString
    '        Else

    '        End If
    '    Next
    '    Return enterdata
    'End Function
End Class

[无·法]

散分的么？谢谢分享

[bcrun]

有人散分就有人接分。楼主贴的代码竟然有大段被注释掉的，呵呵 。

[hotjo110]

引用 3 楼 bcrun 的回复:

有人散分就有人接分。楼主贴的代码竟然有大段被注释掉的，呵呵 。

没有办法啊，思路反复自我否定，到现在都没有搞清楚！

[hotjo110]

Public Class FormPalindromeRecognizer

    Private Sub btnClear_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnClear.Click
        txtTest.Text = String.Empty
        lblAbout.Text = String.Empty
        txtTest.ReadOnly = False
        btnClear.Enabled = False
        btnTest.Enabled = True
        txtTest.Focus()
    End Sub

    Private Sub btnTest_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnTest.Click
        Dim strAbout As String = String.Empty
        'Dim strTest As String
        Dim strEdited As String
    
        Try
            strEdited = removeAllButLettersAndDigits(txtTest.Text)
     
            If strEdited.Length <= 0 Then
                strAbout = "Please enter a string with some letters"
            Else
                'convert string's letters to upper case
                'strEdited = removeAllButLettersAndDigits(txtTest.Text)

                Dim strReversed As String = String.Empty

                strReversed = reverseString(strEdited)

                If strEdited = strReversed Then
                    strAbout = "It is a palindrome"
                Else
                    strAbout = "It is not a palindrome"
                End If
            End If
                'End If

                lblAbout.Text = strAbout
                txtTest.ReadOnly = True
                btnClear.Enabled = True

                btnTest.Enabled = False
            ' End If
   Catch ex As Exception
            MessageBox.Show("Please enter a string")
        End Try
        
    End Sub

    Public Function removeAllButLettersAndDigits(ByVal changeText As String) As String



    
        changeText = changeText.ToUpper

            'filter out non-alphabetic characters
        Dim strEdited As String = String.Empty
        Dim into As String
        Dim intLastPos As Integer = changeText.Length - 1
        Dim x = 0
        Do Until x = intLastPos
            into = changeText.Substring(x, x + 1)
            
            If into >= "A" And into <= "Z" Then
                strEdited = strEdited & into
                x += 1
            ElseIf Int(into) >= 0 And Int(into) <= 9 Then
                strEdited = strEdited & into
                x += 1
            End If
        Loop
        Return strEdited
        'For intPos As Integer = 0 To intLastPos
        '    Dim chrVar As Char = changeText.Chars(intPos)
        '    If chrVar >= "A" And chrVar <= "Z" Then
        '        strEdited = strEdited & chrVar
        '    End If
        'Next

        'Dim i As Long
        'changeText = changeText.ToUpper
        '' Ignore everything except letters and numbers
        'i = 1
        'Do
        '    Select Case Mid(changeText, i, 1)
        '        Case "a" To "z", "0" To "9" : i = i + 1
        '        Case Else : changeText = changeText & changeText.Substring(Mid(i, 1))
        '    End Select
        'Loop While i <= Len(changeText)

        'Return changeText

    End Function

    Public Function reverseString(ByVal convertText As String) As String
        Dim max As Integer

        Dim TextValue As String = String.Empty
        max = convertText.Length - 1
        Dim output As String
        Do Until max <= 0
            output = convertText.Substring(max, max + 1)

            TextValue = output & TextValue
            max -= 1
        Loop

        Return TextValue
    End Function

End Class

现在的思路

[hotjo110]

引用 2 楼 sysdzw 的回复:

散分的么？谢谢分享

当然！

[bcrun]

不过你表述的还不够清楚，如果有个调用示例什么的则更好。

[无·法]

费事，用正则表达式“[a-zA-Z0-9]”，几行代码而已。

[deephill]

用正则表达式确实容易

[lliai]

一个一个字符处理。

[xc_aspnet]

循环一个个的读取判断