sorting text in a text box

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?

VB Code:

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.

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

VB Code:

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)

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.

VB Code:

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

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

VB Code:

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

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

VB Code:

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.

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 :)

Quote:

---

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

---

I thought that was the CString only :confused: