我需要一个强大的和简单的方法来删除非法的路径和文件字符从一个简单的字符串。我已经使用了下面的代码，但它似乎没有做任何事情，我错过了什么?
using System;
using System.IO;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
string illegal = "\"M<>\"\\a/ry/ h**ad:>> a\\/:*?\"<>| li*tt|le|| la\"mb.?";
illegal = illegal.Trim(Path.GetInvalidFileNameChars());
illegal = illegal.Trim(Path.GetInvalidPathChars());
Console.WriteLine(illegal);
Console.ReadLine();
}
}
}
或者你可以这样做
[YOUR STRING].Replace('\\', ' ').Replace('/', ' ').Replace('"', ' ').Replace('*', ' ').Replace(':', ' ').Replace('?', ' ').Replace('<', ' ').Replace('>', ' ').Replace('|', ' ').Trim();
浏览这里的答案，它们似乎都涉及使用无效文件名字符的char数组。
当然，这可能是一种微观优化——但对于那些希望检查大量值是否为有效文件名的人来说，值得注意的是，构建一个由无效字符组成的哈希集将带来明显更好的性能。
过去，我对哈希集(或字典)比遍历列表的速度快得多感到非常惊讶。对于字符串，它是一个低得可笑的数字(从记忆中大约5-7项)。对于大多数其他简单数据(对象引用，数字等)，神奇的交叉似乎是大约20个项目。
路径中有40个无效字符。InvalidFileNameChars“列表”。今天搜索了一下，在StackOverflow上有一个很好的基准测试，显示hashset将花费40个数组/列表一半多一点的时间:https://stackoverflow.com/a/10762995/949129
下面是我用于清理路径的helper类。我现在忘记了为什么我在里面有漂亮的替换选项，但这是一个可爱的奖励。
额外的奖励方法“IsValidLocalPath”:)
(**那些不使用正则表达式的)
public static class PathExtensions
{
private static HashSet<char> _invalidFilenameChars;
private static HashSet<char> InvalidFilenameChars
{
get { return _invalidFilenameChars ?? (_invalidFilenameChars = new HashSet<char>(Path.GetInvalidFileNameChars())); }
}
/// <summary>Replaces characters in <c>text</c> that are not allowed in file names with the
/// specified replacement character.</summary>
/// <param name="text">Text to make into a valid filename. The same string is returned if
/// it is valid already.</param>
/// <param name="replacement">Replacement character, or NULL to remove bad characters.</param>
/// <param name="fancyReplacements">TRUE to replace quotes and slashes with the non-ASCII characters ” and ⁄.</param>
/// <returns>A string that can be used as a filename. If the output string would otherwise be empty, "_" is returned.</returns>
public static string ToValidFilename(this string text, char? replacement = '_', bool fancyReplacements = false)
{
StringBuilder sb = new StringBuilder(text.Length);
HashSet<char> invalids = InvalidFilenameChars;
bool changed = false;
for (int i = 0; i < text.Length; i++)
{
char c = text[i];
if (invalids.Contains(c))
{
changed = true;
char repl = replacement ?? '\0';
if (fancyReplacements)
{
if (c == '"') repl = '”'; // U+201D right double quotation mark
else if (c == '\'') repl = '’'; // U+2019 right single quotation mark
else if (c == '/') repl = '⁄'; // U+2044 fraction slash
}
if (repl != '\0')
sb.Append(repl);
}
else
sb.Append(c);
}
if (sb.Length == 0)
return "_";
return changed ? sb.ToString() : text;
}
/// <summary>
/// Returns TRUE if the specified path is a valid, local filesystem path.
/// </summary>
/// <param name="pathString"></param>
/// <returns></returns>
public static bool IsValidLocalPath(this string pathString)
{
// From solution at https://stackoverflow.com/a/11636052/949129
Uri pathUri;
Boolean isValidUri = Uri.TryCreate(pathString, UriKind.Absolute, out pathUri);
return isValidUri && pathUri != null && pathUri.IsLoopback;
}
}
