. net框架系统。IO对于无效的文件系统字符提供如下功能:

路径。GetInvalidFileNameChars 路径。GetInvalidPathChars

这些函数应该根据. net运行时所在的平台返回适当的结果。也就是说，这些函数的文档页中的备注说:

方法返回的数组不保证包含 文件和目录中无效的完整字符集 的名字。完整的无效字符集可能因文件系统而异。

下面是一个基于Christopher Oezbek的答案的windows c#实现

containsFolder布尔值使它更加复杂，但希望涵盖所有内容

/// <summary>
/// This will replace invalid chars with underscores, there are also some reserved words that it adds underscore to
/// </summary>
/// <remarks>
/// https://stackoverflow.com/questions/1976007/what-characters-are-forbidden-in-windows-and-linux-directory-names
/// </remarks>
/// <param name="containsFolder">Pass in true if filename represents a folder\file (passing true will allow slash)</param>
public static string EscapeFilename_Windows(string filename, bool containsFolder = false)
{
    StringBuilder builder = new StringBuilder(filename.Length + 12);

    int index = 0;

    // Allow colon if it's part of the drive letter
    if (containsFolder)
    {
        Match match = Regex.Match(filename, @"^\s*[A-Z]:\\", RegexOptions.IgnoreCase);
        if (match.Success)
        {
            builder.Append(match.Value);
            index = match.Length;
        }
    }

    // Character substitutions
    for (int cntr = index; cntr < filename.Length; cntr++)
    {
        char c = filename[cntr];

        switch (c)
        {
            case '\u0000':
            case '\u0001':
            case '\u0002':
            case '\u0003':
            case '\u0004':
            case '\u0005':
            case '\u0006':
            case '\u0007':
            case '\u0008':
            case '\u0009':
            case '\u000A':
            case '\u000B':
            case '\u000C':
            case '\u000D':
            case '\u000E':
            case '\u000F':
            case '\u0010':
            case '\u0011':
            case '\u0012':
            case '\u0013':
            case '\u0014':
            case '\u0015':
            case '\u0016':
            case '\u0017':
            case '\u0018':
            case '\u0019':
            case '\u001A':
            case '\u001B':
            case '\u001C':
            case '\u001D':
            case '\u001E':
            case '\u001F':

            case '<':
            case '>':
            case ':':
            case '"':
            case '/':
            case '|':
            case '?':
            case '*':
                builder.Append('_');
                break;

            case '\\':
                builder.Append(containsFolder ? c : '_');
                break;

            default:
                builder.Append(c);
                break;
        }
    }

    string built = builder.ToString();

    if (built == "")
    {
        return "_";
    }

    if (built.EndsWith(" ") || built.EndsWith("."))
    {
        built = built.Substring(0, built.Length - 1) + "_";
    }

    // These are reserved names, in either the folder or file name, but they are fine if following a dot
    // CON, PRN, AUX, NUL, COM0 .. COM9, LPT0 .. LPT9
    builder = new StringBuilder(built.Length + 12);
    index = 0;
    foreach (Match match in Regex.Matches(built, @"(^|\\)\s*(?<bad>CON|PRN|AUX|NUL|COM\d|LPT\d)\s*(\.|\\|$)", RegexOptions.IgnoreCase))
    {
        Group group = match.Groups["bad"];
        if (group.Index > index)
        {
            builder.Append(built.Substring(index, match.Index - index + 1));
        }

        builder.Append(group.Value);
        builder.Append("_");        // putting an underscore after this keyword is enough to make it acceptable

        index = group.Index + group.Length;
    }

    if (index == 0)
    {
        return built;
    }

    if (index < built.Length - 1)
    {
        builder.Append(built.Substring(index));
    }

    return builder.ToString();
}

虽然唯一非法的Unix字符可能是/和NULL，但应该考虑到命令行解释。

例如，虽然在Unix中将文件命名为1>&2或2>&1是合法的，但在命令行中使用这样的文件名可能会被误解。

类似地，也可以将文件命名为$PATH，但当试图从命令行访问它时，shell将把$PATH转换为其变量值。

I always assumed that banned characters in Windows filenames meant that all exotic characters would also be outlawed. The inability to use ?, / and : in particular irked me. One day I discovered that it was virtually only those chars which were banned. Other Unicode characters may be used. So the nearest Unicode characters to the banned ones I could find were identified and MS Word macros were made for them as Alt+?, Alt+: etc. Now I form the filename in Word, using the substitute chars, and copy it to the Windows filename. So far I have had no problems.

下面是替换字符(Alt +十进制Unicode):

⃰ ⇔ Alt8432 ⁄ ⇔ Alt8260 ⃥ ⇔ Alt8421 ∣ ⇔ Alt8739 ⵦ ⇔ Alt11622 ⮚ ⇔ Alt11162 ‽ ⇔ Alt8253 ፡ ⇔ Alt4961 ‵‵ ⇔ Alt8246 “ ⇔ Alt8243

作为测试，我用所有这些字符组成了一个文件名，Windows接受了它。

要让Windows告诉你答案，最简单的方法是尝试通过资源管理器重命名文件，并输入反斜杠/作为新名称。Windows会弹出一个消息框，告诉你非法字符的列表。

A filename cannot contain any of the following characters:
    \ / : * ? " < > | 

微软文档-命名文件，路径和命名空间-命名约定

截至2017年4月18日，这个话题的答案中没有简单的字符和文件名的黑白列表，而且有很多回复。

我能想到的最好的建议是让用户随意命名文件。当应用程序试图保存文件时，使用错误处理程序，捕捉任何异常，假定是文件名造成的错误(显然在确保保存路径也正确之后)，并提示用户输入新的文件名。为了获得最好的结果，将这个检查过程放在一个循环中，直到用户正确或放弃为止。对我来说是最好的工作(至少在VBA)。