Checking a textbox to see if it is alphanumeric

[captainchopsticks07]

I want to make a password cache, and i want it to make sure it contains both Alphbetical and Numerical characters

can anyone help me here

I also want it to be atleast 6 characters long

[HowTo]

you need to use the regular expressions for this kind of checkings......

[captainchopsticks07]

elaborate?

[stateofidleness]

found this:

Public Shared Function IsAlphaNumeric(ByVal strToCheck As String) As Boolean
    Dim pattern As Regex = New Regex("[^a-zA-Z0-9]")
    Return Not pattern.IsMatch(strToCheck)
End Function
 
'You would pass it the .Text property of your textbox. 
IsAlphaNumeric(TextBox1.Text)

[HowTo]

found this:

Public Shared Function IsAlphaNumeric(ByVal strToCheck As String) As Boolean
    Dim pattern As Regex = New Regex("[^a-zA-Z0-9]")
    Return Not pattern.IsMatch(strToCheck)
End Function
 
'You would pass it the .Text property of your textbox. 
IsAlphaNumeric(TextBox1.Text)

and where is this condition as stated by the oz in #1

I also want it to be atleast 6 characters long

[stateofidleness]

oh well damn, let me do all the work for him:

Public Shared Function Isvalid(ByVal strToCheck As String) As Boolean
     If strToCheck.Length >=6 Then
          Dim pattern As Regex = New Regex("[^a-zA-Z0-9]")
          Return pattern.IsMatch(strToCheck)
     Else
          Return False
     End If
End Function
 
'You would pass it the .Text property of your textbox.
IsValid(TextBox1.Text)

[jmcilhinney]

Here's a method without using a Regex:

If myString.All(Function(ch) Char.IsLetterOrDigit(ch)) Then
    'myString is alphanumeric.
End If

That uses LINQ so of course it requires at least .NET 3.5. The advantage of that is that it's not culture-specific, although that probably wouldn't be an issue in most cases anyway.

[captainchopsticks07]

what does Regex mean?

[Tommy.net]

regular expressions

[jmcilhinney]

what does Regex mean?

Looks like they fixed Google.

http://www.google.com.au/search?q=re...ient=firefox-a

[stateofidleness]

lol.

[klin3d]

Makes sure that it has at least either lower case alphabet or upper case alphabet and numbers else it deems it false...

    Public Shared Function IsAlphabet(ByVal alpha As String) As Boolean

        Dim IsA As Boolean = False

        Try
            IsA = (Asc(alpha) >= 65 And Asc(alpha) <= 90) Or (Asc(alpha) >= 97 And Asc(alpha) <= 122)
        Catch ex As Exception
            IsA = False
        End Try

        Return IsA

    End Function

    Public Shared Function CheckIfAlphaNumeric(ByVal strInput As String) As Boolean

        Dim i As Integer
        Dim Chr As Char

        Dim boolNumeric As Boolean
        Dim boolAlphabet As Boolean
        Dim boolUnusedChars As Boolean

        boolNumeric = False
        boolAlphabet = False
        boolUnusedChars = False

        Dim arrBoolNumeric() As Boolean
        Dim arrBoolAlphbet() As Boolean
        Dim arrBoolUnusedChars() As Boolean

        ReDim arrBoolNumeric(0)
        arrBoolNumeric(0) = False

        ReDim arrBoolAlphbet(0)
        arrBoolAlphbet(0) = False

        ReDim arrBoolUnusedChars(0)
        arrBoolUnusedChars(0) = False

        If (strInput.Length = 0) Then
            Return False
        End If

        For i = 0 To strInput.Count - 1

            Chr = strInput.Chars(i)

            If (IsNumeric(Chr) = True) Or (IsAlphabet(Chr) = True) Then

                If (IsNumeric(Chr) = True) Then
                    arrBoolNumeric(arrBoolNumeric.GetUpperBound(0)) = True
                    ReDim Preserve arrBoolNumeric(arrBoolNumeric.GetUpperBound(0) + 1)
                End If

                If (IsAlphabet(Chr) = True) Then
                    arrBoolAlphbet(arrBoolAlphbet.GetUpperBound(0)) = True
                    ReDim Preserve arrBoolAlphbet(arrBoolAlphbet.GetUpperBound(0) + 1)
                End If

            Else
                arrBoolUnusedChars(arrBoolUnusedChars.GetUpperBound(0)) = True
                ReDim Preserve arrBoolUnusedChars(arrBoolUnusedChars.GetUpperBound(0) + 1)
            End If

        Next

        For i = 0 To arrBoolNumeric.GetUpperBound(0) - 1
            If (arrBoolNumeric(i) = False) Then
                boolNumeric = False
                Exit For
            Else
                boolNumeric = True
            End If
        Next

        For i = 0 To arrBoolAlphbet.GetUpperBound(0) - 1
            If (arrBoolAlphbet(i) = False) Then
                boolAlphabet = False
                Exit For
            Else
                boolAlphabet = True
            End If
        Next

        For i = 0 To arrBoolUnusedChars.GetUpperBound(0) - 1
            If (arrBoolUnusedChars(i) = True) Then
                boolUnusedChars = True
                Exit For
            Else
                boolUnusedChars = True
            End If
        Next

        If (boolNumeric = False) Or _
            (boolAlphabet = False) Or _
            (boolUnusedChars = True) Then

            Return False

        Else
            Return True
        End If

    End Function