Question

I have a dictionary collection that stores the starting position and the charecter values of a text file.

For example: a sample text file (a.txt) may contain text like “how are you? how do you do?”

I have indexed the above text as follows

Dictionary<long,string> charLocation = new Dictionary<long,string>(); 

charLocation[0] = "how" 
charLocation[1] = "ow" 
charLocation[2] = "w" 
charLocation[4] = "are" 
charLocation[6] = "e" 
charLocation[5] = "re" 
charLocation[11] = "?" 
charLocation[9] = "ou?" 
charLocation[10] = "u?" 
charLocation[8] = "you?" 
charLocation[13] = "how" 
charLocation[14] = "ow" 
charLocation[15] = "w" 
charLocation[17] = "do" 
charLocation[18] = "o" 
charLocation[21] = "ou" 
charLocation[22] = "u" 
charLocation[20] = "you" 
charLocation[26] = "?" 
charLocation[24] = "do?" 
charLocation[25] = "o?"

Now, I want to highlight each occurrence of “how” or “do” in the text file.

For this I want to first do a lookup in the dictionary collection and find each occurrence of the string, then open the text file and highlight the text for each occurrence.

How can i do this?

Answer 1

Not tested, but this should works.

public string HighLight (int startPoint, string text, string word)
{
  if (startPoint > = 0)
  {
    int startIndex = text.indexOf (word, startPoint);
    if (startIndex >= 0)
    {
      StringBuilder builder = new StringBuilder ();
      builder.Append (text.Substring ( 0, startIndex));
      builder.Append ("<strong>");
      builder.Append (text.Substring (startIndex + 1, word.Length));
      builder.Append ("</strong>");
      builder.Append (text.Substring (startIndex + word.Length + 1));
      return HighLight ((startIndex + "<strong>".Length + "</strong>".Length + word.Length, builder.ToString (), word);
    }
  }

  //Word not found.
  return text;
}

So you could do :

string myText = "how are you? how do you do?";
string hightLightedText = HighLight (0, myText, "how");

And if my code has no errors, that would returns “<strong>how</strong> are you? <strong>how</strong> do you do?”;

Then you can repalce <strong> and </strong> with wathever you want to “highlight” your text.