【C#】C#改变关键字的颜色

        /// <summary>
        /// 改变关键字的颜色
        /// </summary>
        /// <param name="key"></param>
        /// <param name="color"></param>
        public void ChangeKeyColor(string key, Color color)
        {
            Regex regex = new Regex(key);
            //找出内容中所有的要替换的关键字
            MatchCollection collection = regex.Matches(richDetails.Text);
            //对所有的要替换颜色的关键字逐个替换颜色    
            foreach (Match match in collection)
            {
                //开始位置、长度、颜色缺一不可
                richDetails.SelectionStart = match.Index;
                richDetails.SelectionLength = key.Length;
                richDetails.SelectionColor = color;
            }
        }