Textbox displays line break before plus sign

Question

When I have a string like QgMAAB+LCAAAAAAABAB1UtFuwiAU/RXDsw9QrO36tmi2ly3L4mPTmGulSqTQwGWJMf77wBlXExpe4NxzOedcuBCJot8IdKSa1Rci3bsyO1Bvxn7CEMAOlBNzAs6ZVgKK/ in a textbox, it automatically displays a line break before each plus (+) sign:

Can I use auto line breaks (WordWrap) and not let the plus sign make it enter a new line?

I want it to look like this:

(I removed all the plus signs for demonstration)

Answer 1

You can actually override the word break function of the textbox by subclassing your own textbox.

This worked for me:

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace myNamespace
{
    class MyTextBox : TextBox
    {
        const int EM_SETWORDBREAKPROC = 0x00D0;
        const int EM_GETWORDBREAKPROC = 0x00D1;

        delegate int EditWordBreakProc(string lpch, int ichCurrent, int cch, int code);

        protected override void OnHandleCreated(EventArgs e)
        {
            base.OnHandleCreated(e);
            if (!this.DesignMode)
            {
                SendMessage(this.Handle, EM_SETWORDBREAKPROC, IntPtr.Zero, Marshal.GetFunctionPointerForDelegate(new EditWordBreakProc(MyEditWordBreakProc)));
            }
        }

        [DllImport("User32.DLL")]
        public static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);

        int MyEditWordBreakProc(string lpch, int ichCurrent, int cch, int code)
        {
            return 0;
        }
    }
}

This is an modification of the excellent EditWordBreakProc example found here:

Underscore acts as a separator C# RTF Box

Answer 2

This Textbox functionality seems to be by design. Use RichTextBox instead. It does not break on the + sign.

Answer 3

You can set WordWrap = false.

Or you can use RichTextBox instead of TextBox P/S: you can use RichTextBox instead of TextBox ( But you have to set WordWrap = false for RichTextBox too)

Answer 4

Well actually the text format is weird in our case. If you add:

 TextAlignment="Justify"

that would solve your problem with '+' but you will still have a break line after \ because he waits a \n or \t or \r.

Answer 5

It could be a little weird but you can solve the problem of the \ using

String.replace(String, String)

or something similar. You can even try to code your own function. You can check your string and if it occours a " \ ", you'll replace it with " \\ ". I think it should do the trick.

I'm sorry but I don't have enough reputation to add a comment under the fisherXO's answer.

Answer 6

This worked for me:

using System;
using System.Windows.Forms;

namespace Namespace
{
    class CustomTextBox : TextBox
    {
        string _text;
        public CustomTextBox()
        {
            this.Multiline = true;
            this.Wordwrap = true;
            this.KeyDown += new KeyEventHandler(CustomTextBox_KeyDown);
            this.KeyPress += new KeyPressEventHandler(CustomTextBox_KeyPress);
        }

        void CustomTextBox_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == '+')
                e.Handled = true;
            else
                _text = _text + e.KeyChar.ToString();
        }

        void CustomTextBox_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
                e.Handled = true;
            else if (e.KeyCode == Keys.Add)
                _text = _text + @"+";
            this.Text = _text;
        }

    }
}