How to compare two richtextbox text using C#

问题

I have written a logic to compare two ricttext boxes content, but the output difference text is not highlighted at the expected index. It starts ahead of the expected index. I have given below the logic i have used.

private void CompareRichTextContents(RichTextBox target, RichTextBox dest)
    {
        string[] targetLines = target.Lines;
        string[] destLine = dest.Lines;
        List<string> result=targetLines.Except(destLine).ToList<string>();
        foreach (string str in result)
        {

            int lineIndex=Array.IndexOf(targetLines, str);
            int lineCount=0;
            for (int index = 0; index < lineIndex; index++)
            {
                lineCount+=targetLines[index].Length;
            }
            target.SelectionBackColor = Color.Yellow;
            target.SelectionColor = Color.Black;
            target.SelectionStart = lineCount;
            target.SelectionLength = str.Length;

        }
    }

Thanks, Lokesh.

回答1:

look for line feeds that may be the problem

回答2:

Your method is allright however rich textbox only selects one time further, you have to add 1.

Do as below:

private int CompareRichTextContents(RichTextBox target, RichTextBox dest) { int counter = 0; string[] targetLines = target.Lines; string[] destLine = dest.Lines; List result = targetLines.Except(destLine).ToList(); foreach (string str in result) {

            int lineIndex = Array.IndexOf(targetLines, str);
            int lineCount = 0;
            for (int index = 0; index < lineIndex; index++)
            {
                lineCount += targetLines[index].Length+1;
            }
            target.SelectionBackColor = Color.Yellow;
            target.SelectionColor = Color.Black;
           // target.Select(lineCount, str.Length);
             target.SelectionStart = lineCount;
             target.SelectionLength = str.Length;
             counter++;

        }
        return counter; 
    }

Now in button click event, call it as many times as many selections. Though this is calling unnecessary time (writing without thinking much) but each time it will select the next one.

 private void button1_Click(object sender, EventArgs e)
        {
           int counter= CompareRichTextContents(this.richTextBox1Body, this.richTextBox2Body);
           for (int i = 0; i < counter; i++)
               CompareRichTextContents(this.richTextBox1Body, this.richTextBox2Body);
        } 

来源：https://stackoverflow.com/questions/6782195/how-to-compare-two-richtextbox-text-using-c-sharp