Question

如何突破递归，如下所示：

致电GetDirectory("D:\Engine\", "102")

预期输出：D：\ Engine \ Type \ Tone_Id_102
目前，输出为空。

非常感谢。

private static string GetDirectory(string folderPath, string number)
{
    foreach (string directory in Directory.GetDirectories(folderPath))
    {
        if (directory.Contains(number))
        {
            return directory;
        }

        GetDirectory(directory, number);
    }

    return null;
}

Answer 1

这样做不会更容易也更好吗

return Directory.EnumerateDirectories(
        folderPath,
        "*",
        SearchOption.AllDirectories)
    .FirstOrDefault(s => s.Contains(number))

或@TimSchmelter建议，

return Directory.EnumerateDirectories(
        folderPath,
        string.Format("*{0}*", number),
        SearchOption.AllDirectories)
    .FirstOrDefault()

Answer 2

我认为你只需要一个return：

return GetDirectory(directory, number);

然而，这会迭代foreach中的一个条目，所以这会更好：

private static string GetDirectory(string folderPath, string number)
{
    foreach (string directory in Directory.GetDirectories(folderPath))
    {
        if (directory.Contains(number))
        {
            return directory;
        }

        string result = GetDirectory(directory, number);

        if (!string.IsNullOrEmpty(result))
        {
            return result;
        }
    }

    return null;
}

Answer 3

这应该这样做：

private static string GetDirectory(string folderPath, string number)
{
    foreach (string directory in Directory.GetDirectories(folderPath))
    {
        if (directory.Contains(number))
            return directory;

        var innerDir = GetDirectory(directory, number);
        if (innerDir != null)
            return innerDir;
    }

    return null;
}

Answer 4

这也是一样的，我认为它更具可读性：

Directory.GetDirectories(folderPath, "*.*", SearchOption.AllDirectories)
         .FirstOrDefault(x => x.Contains(number));

如何打破递归调用

4 个答案: