c# - TextReader 并查看下一行

Question

我使用 TextReader 从文本文件中读取数据

TextReader reader = new StreamReader(stream);
string line;
while ((line = reader.ReadLine()) != null)
 {
   //.......
 }

有时我需要从阅读器中查看下一行(或几行)。

我该怎么做？

Answer 1

编辑:更新为允许任意数量的窥视:

public class PeekingStreamReader : StreamReader
{
    private Queue<string> _peeks;

    public PeekingStreamReader(Stream stream) : base(stream)
    {
        _peeks = new Queue<string>();   
    }

    public override string ReadLine()
    {
        if (_peeks.Count > 0)
        {
            var nextLine = _peeks.Dequeue();
            return nextLine;
        }
        return base.ReadLine();
    }

    public string PeekReadLine()
    {
        var nextLine = ReadLine();
        _peeks.Enqueue(nextLine);
        return nextLine;
    }
}