find and hightlight text in texbox

go through this link

http://stackoverflow.com/questions/17101889/how-to-create-find-in-notepad-in-c-sharp

hi ...
For textBoxt :
private void findButton_Click(object sender, EventArgs e) { int count = 0; string keyword = keywordTextbox.Text.Trim();//getting given searching string int startPosition = 0; //initializing starting position to search int endPosition = 0; int endArticle = articleRichTextbox.Text.Length;//finding total number of character into the article for (int i = 0; i<endArticle ; i =startPosition )//creating a loop until ending the article { if (i == -1) //if the loop goes to end of the article then stop { break; } startPosition = articleRichTextbox.Find(keyword, startPosition, endArticle, RichTextBoxFinds.WholeWord);//using find method get the begining position when find the searching string if (startPosition >= 0) //if match the string //if don't match the string then it return -1 { count++;//conunting the number of occuerence or match the search string articleRichTextbox.SelectionColor = Color.Blue;//coloring the matching string in the article endPosition = keywordTextbox.Text.Length; startPosition = startPosition + endPosition;//place the starting position at the next word of previously matching string to continue searching. } } if (count == 0)//if the givn search string don't match at any time { MessageBox.Show("No Match Found!!!"); } numberofaccurTextbox.Text = count.ToString();//show the number of occurence into the text box }

Link

For richTextBox :

 private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                int count = 0;
                string keyword = textBox1.Text.Trim();
                int startPosition = 0;
                int endPosition = 0;
                int endArticle = richTextBox1.Text.Length;
                for (int i = 0; i < endArticle; i = startPosition)
                {
                    if (i == -1)
                    {
                        break;
                    }
                    startPosition = richTextBox1.Find(keyword, startPosition, endArticle, RichTextBoxFinds.WholeWord);
                    if (startPosition >= 0)
                    {
                        count++;
                        richTextBox1.SelectionBackColor = Color.PaleGoldenrod;
                        endPosition = textBox1.Text.Length;
                        startPosition = startPosition + endPosition;
                    }
                }
                if (count == 0)
                {
                    MessageBox.Show("???? ???? ??? ???? ???","Find",MessageBoxButtons.OK,MessageBoxIcon.Information);
                }
                MessageBox.Show("????? : " + count + " ???? ???? ??", "Find", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            catch
            {
                MessageBox.Show("????? ?? ???? ? ???? ????? ???? ????","Error",MessageBoxButtons.OK,MessageBoxIcon.Warning);
            }
        }


        private void textBox1_MouseClick(object sender, MouseEventArgs e) //search textBox
        {
            int count = 0;
            string keyword = textBox1.Text.Trim();
            int startPosition = 0;
            int endPosition = 0;
            int endArticle = richTextBox1.Text.Length;
            for (int i = 0; i < endArticle; i = startPosition)
            {
                if (i == -1)
                {
                    break;
                }
                startPosition = richTextBox1.Find(keyword, startPosition, endArticle, RichTextBoxFinds.WholeWord);
                if (startPosition >= 0)
                {
                    count++;
                    richTextBox1.SelectionBackColor = Color.Azure;
                    endPosition = textBox1.Text.Length;
                    startPosition = startPosition + endPosition;
                }
            }
        }
    }