WPF开发txt阅读器实现目录提取功能

class Section
{
    public int order;
    public int location;        //文字位置
    public string title;

    public Section(int order, string title)
    {
        this.order = order;
        this.title = title;
    }

    public Section(int order, string title, string txt, int st=0)
    {
        this.order = order;
        this.title = title;
        location = txt.IndexOf(title, st);
    }
    
    public Section(int order, string title, int location)
    {
        this.order = order;
        this.title = title;
        this.location = location;
    }

}

class Catalog
{
    public List<Section> sections;
    public Catalog(string txt, bool withCatalog)
    {
​​​​​​​    }
}

public int maxSecLength = 30;       // 标题最长字数
public string[] ex = new string[] { "。", "." };

public bool isSection(string paragraph)
{
    if (paragraph.Length > maxSecLength)
        return false;
    foreach (var ch in ex)
        if (paragraph.Contains(ch))
            return false;
    return true;
}


public void extractCatalog(string txt)
{
    int i = 0, num = 0;     //i是章节号；num是章节位置
    foreach (var p in txt.Split("\r\n"))
    {
        num += p.Length;
        if (p.Trim().Length == 0)
            continue;

        if (!isSection(p))
            break;
        secs.Add(new Section(i++, p, txt, num));
    }
}

public void findCatalog(string txt)
{
    int i = 0, num = 0;     //i是章节号；num是章节位置
    foreach (var p in txt.Split("\r\n"))
    {
        num += p.Length;
        if (!isSection(p))
            break;
        secs.Add(new Section(i++, p, num - p.Length));
    }
}