sorting text in a text box

[JMM427]

I am trying to sort letters that are entered into a text box by a user. I want it to sort as the user is leaving the textbox. I thought about using the split method to create an array. The user will be entering a string of letters like "cbdafqg". I want to make sure it sorts to "abcdfgq" upon exiting. Am I on the right track or is there an easier way to do this?

Private Sub txtChangeCode_Leave(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtChangeCode.Leave
        txtChangeCode.Text = txtChangeCode.Text.ToUpper
        Dim strCodes(txtChangeCode.Text.Length) As String
        strCodes = txtChangeCode.Text.Split()
        Array.Sort(strCodes)
        Dim strSorted As String
        Dim i As Integer
        For i = 0 To strCodes.Length - 1
            strSorted = strSorted & strCodes(i)
        Next i
        txtChangeCode.Text = strSorted
    End Sub

Am I correct that you can't split without a delimiter? like a "." or "/", etc.?

Thanks in advance.

[Edneeis]

A string is by nature just an array of characters or char() so you can combine that with the sort method of an array:

Dim str As String = "cdasfg"
        Dim chrs() As Char = str.ToCharArray 'convert string to char array
        Array.Sort(chrs) 'sort
        Dim newstr As New String(chrs) 'convert back to string
        MsgBox(newstr)

[JMM427]

Thanks, that works great.

Now for the bonus question. I want to prevent the user from typing the same character twice in a sequence. I thought the following would work, but it doesn't.

Private Sub txtChangeCode_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txtChangeCode.KeyPress
        If Not (Char.IsLetter(e.KeyChar) Or Char.IsControl(e.KeyChar)) Then
            If InStr(DirectCast(sender, TextBox).Text, e.KeyChar.ToString.ToUpper, CompareMethod.Text) > 0 Then
                e.Handled = True
            End If
        End If
end sub

[Edneeis]

This will work but they can still cut and paste something in but you'll need to handle that seperate if its an issue.

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If TextBox1.Text.Length > 0 Then 'must have text
            Dim c() As Char = TextBox1.Text.ToCharArray() 'get char array
            'check last element of char against current keychar
            If e.KeyChar = c(c.GetUpperBound(0)) Then e.Handled = True
        End If
    End Sub

[JMM427]

That works, but it only compares against the last letter typed. I went one step further and compared against the entire string.

If txtChangeCode.Text.Length > 0 Then
            If InStr(txtChangeCode.Text.ToUpper, e.KeyChar.ToString.ToUpper, CompareMethod.Text) > 0 Then
                e.Handled = True
            End If
                    End If

It works! You're right about the cut and paste problem. I'll have to decide how important that would be to block before I tackle that one.

Thanks again.

[Edneeis]

My bad I thought thats what you meant by 'twice in a sequence', twice in a row is what I was thinking. Your is shorter too

[Kasracer]

Originally posted by Edneeis
A string is by nature just an array of characters

I thought that was the CString only