Old textbox value not being overwritten or cleared

Question

I'm writing a WPF program where I'm trying to enter a phone number in a textbox that must be in the xxx-xxx-xxxx format. I have a key press event that parses the new input and ensures its correct, adds the new number or '-' value to the textbox and returns to wait for the next key press. My issue is this:

text box displays nothing

key press event number 5

textBox parses

call textBox.Text = "5";

exit event handling

text box displays 55 with cursor in between the 5s

Now i'm pretty sure I know that the box is updating but the actual entered text isnt being reset. How do i remove the keystroke so that the text box only displays what I set it to?

Thank you for your time.

Edit: Here's the current code if it helps.

private void PhoneNumberBox_KeyDown(object sender, KeyEventArgs e)
    {
        String keyString = e.Key.ToString();
        char keyPress = 'x';

        if (keyString.Length == 2 && keyString[0] == 'D')
            keyPress = keyString[1];


        TextBox textBox = sender as TextBox;

        if ((keyPress > 47 && keyPress < 58) || keyPress == '-')
        {
            int length = _textBoxText.Length;

            switch (length)
            {
                case 0:
                case 1:
                case 2:
                case 4:
                case 5:
                case 6:
                case 8:
                case 9:
                case 10:
                case 11:
                    {
                        if (keyPress != '-')
                            _textBoxText += keyPress;
                        break;
                    }
                case 3:
                case 7:
                    {
                        if (keyPress == '-')
                            _textBoxText += keyPress;
                        break;
                    }
            }
            textBox.Clear();

            textBox.Text = _textBoxText;
        }
        else
            Invalid_Entry(textBox);
    }

are you asking [masked TextBox](http://stackoverflow.com/questions/481059/where-can-i-find-a-free-masked-textbox-in-wpf) — Lei Yang, May 15 '17 at 02:59
I dont believe so. I'm just starting out on WPF so im using the STL for everything. — Jacob Chesley, May 15 '17 at 03:06
Everything i've used is from vanilla VS 2017, i'm not including any proprietary code. Unless i'm misunderstanding your question. — Jacob Chesley, May 15 '17 at 03:11
you're misunderstanding. almost all of the code are open source. — Lei Yang, May 15 '17 at 03:12

score 0 · Answer 1 · answered May 15 '17 at 03:34

0

My issue was the fact that the event didn't realize it was handled. All I needed to do was:

e.Handled = true;

and my issue went away.

answered May 15 '17 at 03:34

Jacob Chesley

131
1
10

The event cannot realize it, you had to tell. – Sir Rufo May 15 '17 at 04:23

Old textbox value not being overwritten or cleared

1 Answers1