我正在尝试基于模式创建一个彩色RichTextBox。
正文是：

Hey, This{Red} IS A {Cyan}sample. The {Green}color is green color

每个{ }包含一种颜色，它是下一个单词的样式：
嘿，这是一个颜色是绿色的颜色
Hey, This默认颜色。
IS A应为红色。
sample. The应为青色。
color is green color应为绿色。
下面是我的代码：

// Hey, This{Red} IS A {Cyan}sample. The {Green}color is green color
// shown text should be:
// Hey, This IS A sample. The color is green

const string OriginalText = "Hey, This{Red} IS A {Cyan}sample. The {Green}color is green color";
const string ShownText = "Hey, This IS A sample. The color is green color";
const string Pattern = "(?<=\\{)(.*?)(?=\\})";

rtbMain.Text = ShownText;

rtbMain.SelectAll();
rtbMain.SelectionColor = Color.Black;
rtbMain.SelectionBackColor = Color.White;
Regex regex = new(Pattern, RegexOptions.IgnoreCase);
MatchCollection matches = regex.Matches(OriginalText);

if (matches.Count > 0)
{
    var rtbText = rtbMain.Text;
    var length = ShownText.Length;
    var allMatches = new List<Match>();

    for (int i = 0; i < matches.Count; i++)
    {
        var m = matches[i];
        allMatches.Add(m);
        Match nextMatch = null;
        if (matches.Count > i + 1)
        {
            nextMatch = matches[i + 1];
        }
        var sum = GetSum();
        var start = m.Index;
        var currentLength = m.Length;
        if (nextMatch != null)
        {
            var end = nextMatch.Index - start- sum;
            rtbMain.Select(start- 1, end);
        }
        else
        {
            var currentIndex = OriginalText.IndexOf(m.Value);
            rtbMain.Select(length - currentIndex, (length - currentIndex) - sum);
        }
        rtbMain.SelectionColor = GetColor(m.Value);
    }
    int GetSum()
    {
        return allMatches!.Select(m => m.Value.Length - 1).Sum();
    }
    Color GetColor(string color)
    {
        return Color.FromName(color);
    }
}
else
{
    Debug.WriteLine("No matches found");
}

由于RichTextBox没有颜色标记，我不知道如何计算索引/长度的正确位置。
屏幕截图：