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Hyperlink to a line of RichTextBox in C#

I am looking a way to create a HyperLink in a RichTextBox pointing to a line of the text of the same RichTextBox.
I just found how to do that with Internet Links but I don't find a way to do it with the same text inside of the control (It's like Hyperlinks in MS Word pointing to a header or bookmark).
Thanks in Advance. - CCB

No, this will not work unless you code the necessary stuff yourself.
Two suggestions:
A simple workaround with links always starting with www.
The nicer solution with arbitrary link text
Let's have a look at both options..:
Using the built-in functionality of recognizing an URL seems the right way to start, but the link will always have to look like a URL, not like a hyperlink to an anchor.. If you can live with a solution that has, say, links like this: www.goto.234 and anchors like this: #234# this is really rather simple..
A working example can be as simple as this:
private void richTextBox1_LinkClicked(object sender, LinkClickedEventArgs e)
{
var s = e.LinkText.Split('.');
string anchor = s[2];
int a = richTextBox1.Text.IndexOf("#" + anchor + "#" );
if (a >= 0) richTextBox1.SelectionStart = a; else return; // do add more checks!
richTextBox1.SelectionLength = 0;
Text = anchor + " # " + a;
//richTextBox1.ScrollToCaret(); <<--- this crashes on my machine!
// so I take the jump out of the click event and it works:
Timer ttt = new Timer() { Interval = 100 };
ttt.Tick += (ss, ee) => { richTextBox1.ScrollToCaret(); ttt.Stop(); };
}
Option two: If you'd rather have more choice of how the links should read you can do this:
Start by formatting each to
Start with a special character, say a tilde '~'
format it to look blue and underlined if you want to
Either make it one word or replace space by underlines and format those to have the forecolor equal to the backcolor
Now this can do the job:
public string delimiters = " ()[]{}!&?=/\\,;.\r\n";
private void richTextBox2_Click(object sender, EventArgs e)
{
int sstart = -1;
string s = getWordAt(richTextBox2.Text,
richTextBox2.SelectionStart, delimiters, out sstart);
if (s.Length < 3) return;
string char1 = s.Substring(0, 1);
if (char1 == "~")
{
int p = richTextBox2.Text.IndexOf("#" + s.Substring(1));
if (p >= 0) { richTextBox2.SelectionStart = p; richTextBox2.ScrollToCaret(); }
}
}
public static string getWordAt(string text, int cursorPos,
string delimiters, out int selStart)
{
int startPos = 0;
selStart = startPos;
if ((cursorPos < 0) | (cursorPos > text.Length) | (text.Length == 0)) return "";
if ((text.Length > cursorPos) & (delimiters.Contains(text[cursorPos]))) return "";
int endPos = text.Length - 1;
if (cursorPos == text.Length) endPos = text.Length - 1;
else { for (int i = cursorPos; i < text.Length; i++)
{ if (delimiters.Contains(text[i])) { endPos = i - 1; break; } } }
if (cursorPos == 0) startPos = 0;
else { for (int i = cursorPos; i > 0; i--)
{ if (delimiters.Contains(text[i])) { startPos = i + 1; break; } } }
selStart = startPos;
return text.Substring(startPos, endPos - startPos + 1);
}
Here are the two versions side by side, once at the top then after clicking on a link:
Both versions work fine, although both could do with some more checks.
Note that I was too lazy to format the pseudo-links in the second example, so they show their tildes and hashes..
Not hard to write a helper function that can insert the formatting; the search will still work as it searches in the Text, not the Rtf property..

Replace all text in a rich text box

I have a problem while trying to replace all text matching a particular word in a rich text box. This is the code i use
public static void ReplaceAll(RichTextBox myRtb, string word, string replacer)
{
int index = 0;
while (index < myRtb.Text.LastIndexOf(word))
{
int location = myRtb.Find(word, index, RichTextBoxFinds.None);
myRtb.Select(location, word.Length);
myRtb.SelectedText = replacer;
index++;
}
MessageBox.Show(index.ToString());
}
private void btnReplaceAll_Click(object sender, EventArgs e)
{
Form1 text = (Form1)Application.OpenForms["Form1"];
ReplaceAll(text.Current, txtFind2.Text, txtReplace.Text);
}
This works well but i have noticed a little malfunction when i try to replace a letter with itself and another letter.
For example i want to replace all the e in Welcome to Nigeria with ea.
This is what i get Weaalcomeaaaaaaa to Nigeaaaaaaaaaaaaaaria.
And the message box shows 23 when there are only three e. Pls what am i doing wrong and how can i correct it

Simply do this:
yourRichTextBox.Text = yourRichTextBox.Text.Replace("e","ea");
If you want to report the number of matches (which are replaced), you can try using Regex like this:
MessageBox.Show(Regex.Matches(yourRichTextBox.Text, "e").Count.ToString());
UPDATE
Of course, using the method above has expensive cost in memory, you can use some loop in combination with Regex to achieve some kind of advanced replacing engine like this:
public void ReplaceAll(RichTextBox myRtb, string word, string replacement){
int i = 0;
int n = 0;
int a = replacement.Length - word.Length;
foreach(Match m in Regex.Matches(myRtb.Text, word)){
myRtb.Select(m.Index + i, word.Length);
i += a;
myRtb.SelectedText = replacement;
n++;
}
MessageBox.Show("Replaced " + n + " matches!");
}

C# Need help editing my line numbering code

I got a code for line numbering, it works perfectly fine for numbering lines the regular way but I'm looking for something a little bit different. I want my code to only count line breaks when i press enter(the program receives an return keycode) and not then the textbox automatically cut the lines with word wrapping. This is the code i'm using right now:
//Instructions
int maxLC = 1; //maxLineCount - should be public
private void InstructionsSyncTextBox_KeyUp(object sender, KeyEventArgs e)
{
int linecount = InstructionsSyncTextBox.GetLineFromCharIndex(InstructionsSyncTextBox.TextLength) + 1;
if (linecount != maxLC)
{
InstructionsLineNumberSyncTextBox.Clear();
for (int i = 1; i < linecount + 1; i++)
{
InstructionsLineNumberSyncTextBox.AppendText(Convert.ToString(i) + "\n");
}
maxLC = linecount;
}
}
How i think i would be done easiest is by saving the line count every time someone presses enter to a list and also everytime someone presses enter it updates the line number texbox with every line number at positions said in list. But i have no idea how to detect when an return is removed. Anybody knows how to solve this?

Extremely basic example that counts the lines in your code you posted:
class Program
{
static void Main(string[] args)
{
string stringFromTextBox =
#" int maxLC = 1; //maxLineCount - should be public
private void InstructionsSyncTextBox_KeyUp(object sender, KeyEventArgs e)
{
int linecount = InstructionsSyncTextBox.GetLineFromCharIndex(InstructionsSyncTextBox.TextLength) + 1;
if (linecount != maxLC)
{
InstructionsLineNumberSyncTextBox.Clear();
for (int i = 1; i < linecount + 1; i++)
{
InstructionsLineNumberSyncTextBox.AppendText(Convert.ToString(i) + ""\n"");
}
maxLC = linecount;
}
}";
Regex r = new Regex("\r", RegexOptions.Multiline);
int lines = r.Matches(stringFromTextBox).Count;
//You'll need to run this line every time the user presses a key
}
}

How to select RichTextBox text given an index and length

If you are only given an index and length (or EndIndex) of a certain text to select, how do you perform this in WPF version of RichTextBox?
This is very doable in Textbox as you can call Textbox.Select(startIndex,Length) but I don't see anything equivalent in RTB.
Edit: I have found the answer to making a selection
internal string Select(RichTextBox rtb, int index, int length)
{
TextRange textRange = new TextRange(rtb.Document.ContentStart, rtb.Document.ContentEnd);
if (textRange.Text.Length >= (index + length))
{
TextPointer start = textRange.Start.GetPositionAtOffset(index, LogicalDirection.Forward);
TextPointer end = textRange.Start.GetPositionAtOffset(index + length, LogicalDirection.Backward);
rtb.Selection.Select(start, end);
}
return rtb.Selection.Text;
}
However, when I try to highlight the line after the selection has been made:
rtb.Selection.ApplyPropertyValue(TextElement.BackgroundProperty, new SolidColorBrush(Colors.LightBlue));
The highlighting feature works only on the first try and breaks after second try. Anyone know the reason for this?

Ok this question is old but i finally found the Answer so i put this here.
I was having similiar issues when i tried to make some Syntaxhighlighter using the RichTextBox.
What I found out is, that when you play arround with ApplyPropertyValue you cannot simply use GetPositionAtOffset anymore. I believe that applying propertyvalues seems to change the "internal positions" of TextTokens inside the Document, hence 'braking' this functionality.
The Workaround:
Everytime you need to work with GetPositionAtOffset first call ClearAllProperties on the complete TextRange of the Document, then reapply all your properties using ApplyPropertyValue but thistime from right to left. (right means highest offset)
I dont know if you had applied any PropertyValues expect the Selection highlighting, so you might need to put more thinking inthere.
This is how my code looked when it caused the Problem:
private void _highlightTokens(FlowDocument document)
{
TextRange fullRange = new TextRange(document.ContentStart, document.ContentEnd);
foreach (Token token in _tokenizer.GetTokens(fullRange.Text))
{
TextPointer start = fullRange.Start.GetPositionAtOffset(token.Position);
TextPointer end = start.GetPositionAtOffset(token.Length);
TextRange range = new TextRange(start, end);
range.ApplyPropertyValue(TextElement.ForegroundProperty, _getTokenColor(token));
}
}
And i fixed it like this:
private void _highlightTokens(FlowDocument document)
{
TextRange fullRange = new TextRange(document.ContentStart, document.ContentEnd);
fullRange.ClearAllProperties(); // NOTICE: first remove allProperties.
foreach (Token token in _tokenizer.GetTokens(fullRange.Text).Reverse()) // NOTICE: Reverse() to make the "right to left" work
{
TextPointer start = fullRange.Start.GetPositionAtOffset(token.Position);
TextPointer end = start.GetPositionAtOffset(token.Length);
TextRange range = new TextRange(start, end);
range.ApplyPropertyValue(TextElement.ForegroundProperty, _getTokenColor(token));
}
}

Use the Select() method on the RichTextBox.Selection property.

Blockquote you can get the text between spaces.....
private string RichWordOver(RichTextBox rch, int x, int y)
{
int pos = rch.GetCharIndexFromPosition(new Point(x, y));
if (pos <= 0) return "";
string txt = rch.Text;
int start_pos;
for (start_pos = pos; start_pos >= 0; start_pos--)
{
char ch = txt[start_pos];
if (!char.IsLetterOrDigit(ch) && !(ch=='_')) break;
}
start_pos++;
int end_pos;
for (end_pos = pos; end_pos < txt.Length; end_pos++)
{
char ch = txt[end_pos];
if (!char.IsLetterOrDigit(ch) && !(ch == '_')) break;
}
end_pos--;
if (start_pos > end_pos) return "";
return txt.Substring(start_pos, end_pos - start_pos + 1);
}
private void rchText_MouseClick(object sender, MouseEventArgs e)
{
MessageBox.Show(RichWordOver(rchText, e.X, e.Y));
}

How to color some words in differents lines in the RichTextBox?

I'm in trouble, today I tried to color some diffents words in differents lines clicked on a button. Can You explain me how to do this? I was able to do only this:
private void button1_Click(object sender, EventArgs e)
{
richTextBox1.Select(int start , int length); //It's wrong but It explains How to use .Select if you know start and length...
richTextBox1.SelectionColor = Color.Blue;
}
But how can I work on a line I know the number of, having already the text into the RichTextBox?
Thanks.

If lines are separated by \n, your problem is then to count the number of \n characters before getting to the wanted line.
For that, you can use an extension method:
public static int NthIndexOf(this String str, String match, int occurence) {
int i = 1;
int index = 0;
while (i <= occurence && ( index = str.IndexOf(match, index + 1) ) != -1) {
if (i == occurence) {
// Occurence match found!
return index;
}
i++;
}
// Match not found
return -1;
}
Now, you can find start and end values to color the selection:
private void button1_Click(object sender, EventArgs e) {
int lineNb = 13; // I assume you get this value initialized somewhere,
// I wrote 13 for the example
int start = richTextBox1.Text.NthIndexOf("\n", lineNb);
int length = richTextBox1.Text.NthIndexOf("\n", lineNb + 1);
richTextBox1.Select(start , length);
richTextBox1.SelectionColor = Color.Blue;
}