C# RichTextBox strange behaviour

Question

greetings,

for the first time ever im investigating RichTextBox control in C# windows forms. i know i need this control in my app as textBox is to simple for my needs.

i have the followig code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace _19_richtextbox
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void richTextBoxHome_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyValue == (char)(Keys.Return))
            {
                richTextBoxChat.AppendText("Home:" + richTextBoxHome.Text + "\n");
                richTextBoxHome.Clear();
            }
        }
    }
}

for the moment i just want whatever is typed in one richtextbox to be displayed on the other richtextbox on hitting return.

the issue is everytime i hit return the data is being transfered to the other control but the first control is left with a carriage return before the cursor. this happens everytime i hit return.

how do i make it stop doing this?

both the controls accept multiline input.

please advise if i need to provide more info.

thank you for your time.

new to this hopefully the code is readable.

---

i would like a way to make the "Home:" part in bold.

i have found very little info on this on my searches. the following are the only actual code that i could understand.

rtb1.Rtf = @"{\rtf1\ansi {\b hello} {\i World}}" ;

richTextBox1.Rtf = @"{\rtf1\ansi This is in \b bold\b0.}";

---

im not sure how to proceed with this info. i just want the richtextbox to display "Home:" and "Away:" in bold and be able to handle URLs in text.

please advise what should i specify when searching this potic on google or any reference your could think of would be of great help.

thank you again for taking interest.

---

i have made progress on my issue and thought to share.

using System;

using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms;

namespace _19_richtextbox { public partial class Form1 : Form { public Form1() { InitializeComponent(); }

    private void richTextBoxHome_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (e.KeyChar == (char)(Keys.Enter))
        {
            e.Handled = true;

            // richTextBoxChat.Rtf = @"{\rtf1 \b Home: \bO}" + @richTextBoxHome;

            // do not delete next 2 lines
            //string test = @"{\rtf1 \b Home: \b0";
            //test = test + richTextBoxHome.Rtf + "}";

            string chatBuffer = richTextBoxChat.Rtf;

            string buffer = @"{\rtf1";
            buffer = buffer + chatBuffer;

            buffer = buffer + @"\b Home:\b0";

            buffer = buffer + richTextBoxHome.Rtf + "}";


           // MessageBox.Show(buffer);
            richTextBoxChat.Rtf = buffer;
            //do not delete the following 2 lines
            //richTextBoxChat.AppendText("Home:" + richTextBoxHome.Text);
            richTextBoxHome.Clear();
        }
    }

}

}

---

just need to figure out how to get rid of the new lines/carriage returns in the text.

any tips most welcome.

thanks.

---

that did not workout so well. ended up using the below instead.

                this.richTextBoxChat.SelectionFont = new Font(this.richTextBoxChat.Font.FontFamily, this.Font.Size, FontStyle.Bold);
            richTextBoxChat.AppendText("Home: ");
            this.richTextBoxChat.SelectionFont = new Font(this.richTextBoxChat.Font.FontFamily, this.Font.Size, FontStyle.Regular);
            richTextBoxChat.AppendText(richTextBoxHome.Text);
            richTextBoxChat.ScrollToCaret();
            richTextBoxHome.Clear();

thanks for all the help.

Answer 1

You can set the event to handled to prevent further processing of the return keydown event

Try this:

    private void richTextBoxHome_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyValue == (char)(Keys.Return))
        {
            richTextBoxChat.AppendText("Home:" + richTextBoxHome.Text + "\n");
            richTextBoxHome.Clear();

            e.Handled = true;
            e.SuppressKeyPress = true;

        }
    }

Edit: added e.SuppressKeyPress = true; Cory Charlton pointed this out in his post.

Edit: also, as others have mentioned, use the KeyPress event handler, so if someone holds down enter/return the event is triggered over and over again. an example of the usage is as follows:

    private void richTextBoxHome_KeyPress(object sender, KeyPressEventArgs e)
    {
        if (e.KeyChar.Equals((Char) Keys.Enter))
        {
            richTextBoxChat.AppendText("Home:" + richTextBoxHome.Text + "\n");
            richTextBoxHome.Clear();

            e.Handled = true;
        }
    }

Edit: Also, there is a Property you can set on the RichTextBox to not allow MultiLine strings to be entered into the textbox. This does pose a problem when pasting content with multiple lines, it will only take the first line.

For Bold words: You can change the SelectionFont of the RichTextBox to set it's font attributes:

    private readonly Font BoldSelectionFont = new Font("Arial", 9.0f, FontStyle.Bold);
    private readonly Font RegSelectionFont = new Font("Arial", 9.0f, FontStyle.Regular);

...
                richTextBoxChat.SelectionFont = BoldSelectionFont;
                richTextBoxChat.AppendText("Home: ");
                richTextBoxChat.SelectionFont = RegSelectionFont;
                richTextBoxChat.AppendText(richTextBoxHome.Text + "\n");
...

Answer 2

To suppress the KeyDown event, write e.Handled = true.

Also, the best way to check what key was pressed is to write if (e.KeyCode == Keys.Enter)

Answer 3

Use the KeyPress instead of KeyDown and set e.Handled=true

Answer 4

Handle and supress the key stroke:

    private void richTextBoxHome_KeyDown(object sender, KeyEventArgs e)
    {
        if (e.KeyValue == (char)(Keys.Return))
        {
            richTextBoxChat.AppendText("Home:" + richTextBoxHome.Text + "\n");
            richTextBoxHome.Clear();

            e.Handled = true;
            e.SuppressKeyPress = true;
        }
    }