How to make a TextBox when I type `@` the cursor automatically go to the begin of the textbox C#

Question

I have textBox and I want when I type @ the cursor automatically go to the begin of the textbox (like you pressed the Home Button on the keyboard) I tried this code

richTextBox1.Select(0, 0);

but it's not working as I want ( like when you press the home button on keyboard ) this is the all of the code

private void RichTextBox1_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (!Char.IsLetterOrDigit(e.KeyChar))
        {
            richTextBox1.Select(0, 0);
            checkLog = true;
        }
    }

Your question actually requires a Javascript solution. It's therefore not a C# or ASP.NET question. — ProgrammingLlama, Oct 06 '20 at 06:40
Are you sure you execute the code when you add the @ sign. Could you provide more code please? — IndieGameDev, Oct 06 '20 at 06:40
How exactly does it not work the way you want it to? What are you seeing, and what did you hope so see? Where have you placed this `Select()` call? Please [edit] into your question more code and more details. — Ken Y-N, Oct 06 '20 at 06:43
No, I said your question is about Javascript as that's what is required for real-time interactive changes to your page. Web applications aren't like traditional desktop applications, so things like keypresses aren't streamed to the server. — ProgrammingLlama, Oct 06 '20 at 06:43
So how does or doesn't this work? Have you placed a breakpoint and checked whether your code ends up in this method? — CodeCaster, Oct 06 '20 at 07:02

Hossein Ebrahimi · Answer 1 · 2020-10-06T07:10:24.973

0

This does the work:

private void richTextBox1_TextChanged(object sender, EventArgs e)
{
    if(richTextBox1.Text.Contains('@'))
    {
        richTextBox1.Select(0, 0);
    }
}

KeyPress event actually happens before the character get added to the textbox so with KeyPress it actually goes to the beginning of the textbox and then adds the '@' there.

edited Oct 06 '20 at 07:10

answered Oct 06 '20 at 06:56

Hossein Ebrahimi

632
10
20

score 0 · Accepted Answer · answered Oct 06 '20 at 07:09

TextChanged event and String.IndexOf will get the job done, String.Contains is another option for readability and it calls IndexOf internally Is String.Contains() faster than String.IndexOf()?

private void richTextBox1_TextChanged(object sender, EventArgs e)
{
    if (richTextBox1.Text.IndexOf("@") > -1)
    {
        richTextBox1.Select(0, 0);
    }
}

How to make a TextBox when I type `@` the cursor automatically go to the begin of the textbox C#

2 Answers2