C# – Rich Text Box – Bold

crichtextbox

I know there are loads of "how to bolden text" questions on here, but none of the answers are helping, I think it may be that the Rich Text Box is being created at runtime.

I'm making a chat client, so I have a rich text box split up in lines and the messages are as follows:
{Name}: {Message} \r\n

I want to bolden the name, I have tried many code examples, but this is the closest I've got to it working:

int length = textBox.Text.Length;
textBox.Text += roomChatMessage.from + ": " + roomChatMessage.text + "\r\n";
textBox.Select(length, roomChatMessage.from.Length);
textBox.SelectionFont = new Font(textBox.Font, FontStyle.Bold);

The first message, it works perfectly fine, the name is in bold. But when I add a second message, everything turns bold even though the second time round I'm selecting the start index (Which is this example is 37) but everything just turns bold, all the past messages too!

Any idea to what may cause this?
Thanks in advance!

Best Answer

 ObjRichTextBox.SelectionFont = new Font(ObjRichTextBox.Font, FontStyle.Bold);

 ObjRichTextBox.AppendText("BOLD TEXT APPEARS HERE");

 ObjRichTextBox.SelectionFont = new Font(ObjRichTextBox.Font, FontStyle.Regular);

 ObjRichTextBox.AppendText("REGULAR TEXT APPEARS HERE");

Hope this helps :)

Related Solutions

C# – How to maintain RichText formatting (bold/italic/etc) when changing any one element

RTB does not support this well. You cannot even discover the range of characters within the selection that has the same font style. Start by checking the SelectionFont property first, it will be null if the selection contains a mix of styles. If that's the case, you'll have to iterate the selection one character at a time by setting the SelectionStart and SelectionLength properties, read the SelectionFont until it changes. Apply the changed font to the range you discovered.

Check this answer for a way to keep this reasonably quick and flicker-free.

Note that implementing an editor with RTB is a favorite topic at codeproject.com. Borrowing code, if not the entire project, is a good way to lessen the pain.

C# – How to add bold text to rich text box

In order to make the text bold you just need to surround the text with \b and use the Rtf member.

this.notes_pln.Rtf = @"{\rtf1\ansi this word is \b bold \b0 }";

OP mentioned that they will be adding lines over time. If that is the case then this could be abstracted away into a class

class RtfBuilder { 
  StringBuilder _builder = new StringBuilder();

  public void AppendBold(string text) { 
    _builder.Append(@"\b ");
    _builder.Append(text);
    _builder.Append(@"\b0 ");
  }

  public void Append(string text) { 
    _builder.Append(text);
  }

  public void AppendLine(string text) { 
    _builder.Append(text);
    _builder.Append(@"\line");
  }

  public string ToRtf() { 
    return @"{\rtf1\ansi " + _builder.ToString() + @" }";
  }
}

Best Answer

Related Solutions

C# – How to maintain RichText formatting (bold/italic/etc) when changing any one element

C# – How to add bold text to rich text box

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