How to compare two rich text fields and highlight characters that have been changed?

Question

The code I used to read the contents of 2 richtextbox looks like this:

richTextBox1.Text = File.ReadAllText(tfsVersionFilePath);
richTextBox2.Text = File.ReadAllText(dbVersionFilePath);

Now I need to compare the contents of a rich text field and highlight the characters that have been changed in both richtextboxes. The goal is to get the difference and highlight the characters as in TFS(file comparison) using the C # application. Thank.

Edit:

int length = (richTextBox1.Text.Length > richTextBox2.Text.Length) ? richTextBox1.Text.Length : richTextBox2.Text.Length;
for (int i = 0; i < length; i++)
{ 
   if (richTextBox1.Text[i] != richTextBox2.Text[i])
   {
      /* and then start your highlight selection here, 
      this is where some difference between the two rich 
      text boxes begins */

      richTextBox1.Select(i, 1); 
      richTextBox1.SelectionColor = System.Drawing.Color.Yellow; 
      richTextBox1.SelectionBackColor = System.Drawing.Color.Red;
   }
}

What I understood from debugging is that the method Selector SelectionColoror SelectionBackColorrichTextBox1 pointing to the text cursor has increased to 7 positions after certain lines have been executed. How to save cursor position in richTextBox1?

Answer 1

ArtyomZzz , DiffMatchPatch!

, RichTextboxes .

diff-match-patchsource. (. !) ZIP "DiffMatchPatch.cs", "COPY" cs . .

using DiffMatchPatch;

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

    // this is the diff object;
    diff_match_patch DIFF = new diff_match_patch();

    // these are the diffs
    List<Diff> diffs;

    // chunks for formatting the two RTBs:
    List<Chunk> chunklist1; 
    List<Chunk> chunklist2;

    // two color lists:
    Color[] colors1 = new Color[3] { Color.LightGreen, Color.LightSalmon, Color.White };
    Color[] colors2 = new Color[3] { Color.LightSalmon, Color.LightGreen, Color.White };


    public struct Chunk
    {
        public int startpos;
        public int length;
        public Color BackColor;
    }


    private void button1_Click(object sender, EventArgs e)
    {
        diffs = DIFF.diff_main(RTB1.Text, RTB2.Text);
        DIFF.diff_cleanupSemanticLossless(diffs);      // <--- see note !

        chunklist1 = collectChunks(RTB1);
        chunklist2 = collectChunks(RTB2);

        paintChunks(RTB1, chunklist1);
        paintChunks(RTB2, chunklist2);

        RTB1.SelectionLength = 0;
        RTB2.SelectionLength = 0;
    }


    List<Chunk> collectChunks(RichTextBox RTB)
    {
        RTB.Text = "";
        List<Chunk> chunkList = new List<Chunk>();
        foreach (Diff d in diffs)
        {
            if (RTB == RTB2 && d.operation == Operation.DELETE) continue;  // **
            if (RTB == RTB1 && d.operation == Operation.INSERT) continue;  // **

            Chunk ch = new Chunk();
            int length = RTB.TextLength;
            RTB.AppendText(d.text);
            ch.startpos = length;
            ch.length = d.text.Length;
            ch.BackColor = RTB == RTB1 ? colors1[(int)d.operation]
                                       : colors2[(int)d.operation];
            chunkList.Add(ch);
        }
        return chunkList;

    }

    void paintChunks(RichTextBox RTB, List<Chunk> theChunks)
    {
        foreach (Chunk ch in theChunks)
        {
            RTB.Select(ch.startpos, ch.length);
            RTB.SelectionBackColor = ch.BackColor;
        }

    }

  }
}

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. . , . cleanupSemanticLossless. , , .

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cleanupSemanticLossless:

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Answer 2

, :

• 2
• .net-.

- https://github.com/curran/google-diff-match-patch ( https://code.google.com/p/google-diff-match-patch/, )

( , ) Html ( ). ( html ) - . DiffMatchPatch.diff_prettyHtml (...) ( ).

p.s.

if (richTextBox1.Text [i]!= richTextBox2.Text [i])

. .

Answer 3

, :

int length = (richTextBox1.Text.Length > richTextBox2.Text.Length) ? richTextBox1.Text.Length : richTextBox2.Text.Length;
for (int i = 0; i < length; i++)
{ 
   if (richTextBox1.Text[i] != richTextBox2.Text[i])
   {
      /* and then start your highlight selection here, 
      this is where some difference between the two rich 
      text boxes begins */
   }

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, , . .