c# - 正则表达式匹配 rar 存档文件集中的第一个文件

Question

我该怎么做？我见过一个解决方案，因为 ruby​​ 不支持 loookaround 断言，所以不对 ruby​​ 使用单个正则表达式。但是在 C# 中可能吗？

[Test]
public void RarArchiveFirstFileNameShouldMatch() {
    var regex = new Regex(@"\.(rar|001)$", RegexOptions.IgnoreCase | RegexOptions.Singleline);
    Assert.That(regex.IsMatch("filename.001"));
    Assert.That(regex.IsMatch("filename.rar"));
    Assert.That(regex.IsMatch("filename.part1.rar"));
    Assert.That(regex.IsMatch("filename.part01.rar"));
    Assert.That(regex.IsMatch("filenamepart44.rar"));
    Assert.That(regex.IsMatch("filename.004"), Is.False);
    Assert.That(regex.IsMatch("filename.057"), Is.False);
    Assert.That(regex.IsMatch("filename.r67"), Is.False);
    Assert.That(regex.IsMatch("filename.s89"), Is.False);
    Assert.That(regex.IsMatch("filename.part2.rar"), Is.False);
    Assert.That(regex.IsMatch("filename.part04.rar"), Is.False);
    Assert.That(regex.IsMatch("filename.part11.rar"), Is.False);
}

Answer 1

这应该通过你的测试:

    var regex = new Regex(@"(\.001|\.part0*1\.rar|^((?!part\d*\.rar$).)*\.rar)$", RegexOptions.IgnoreCase | RegexOptions.Singleline);
    Assert.That(regex.IsMatch("filename.001"));
    Assert.That(regex.IsMatch("filename.rar"));
    Assert.That(regex.IsMatch("filename.part1.rar"));
    Assert.That(regex.IsMatch("filename.part01.rar"));
    Assert.That(regex.IsMatch("filename.004"), Is.False);
    Assert.That(regex.IsMatch("filename.057"), Is.False);
    Assert.That(regex.IsMatch("filename.r67"), Is.False);
    Assert.That(regex.IsMatch("filename.s89"), Is.False);
    Assert.That(regex.IsMatch("filename.part2.rar"), Is.False);
    Assert.That(regex.IsMatch("filename.part04.rar"), Is.False);
    Assert.That(regex.IsMatch("filename.part11.rar"), Is.False);