下面是一个用替换字符替换文件名中所有非法字符的函数:

public static string ReplaceIllegalFileChars(string FileNameWithoutPath, char ReplacementChar)
{
  const string IllegalFileChars = "*?/\\:<>|\"";
  StringBuilder sb = new StringBuilder(FileNameWithoutPath.Length);
  char c;

  for (int i = 0; i < FileNameWithoutPath.Length; i++)
  {
    c = FileNameWithoutPath[i];
    if (IllegalFileChars.IndexOf(c) >= 0)
    {
      c = ReplacementChar;
    }
    sb.Append(c);
  }
  return (sb.ToString());
}

例如，下划线可以用作替换字符:

NewFileName = ReplaceIllegalFileChars(FileName, '_');

你可以像这样使用Linq删除非法字符:

var invalidChars = Path.GetInvalidFileNameChars();

var invalidCharsRemoved = stringWithInvalidChars
.Where(x => !invalidChars.Contains(x))
.ToArray();

编辑 以下是评论中提到的经过必要编辑后的效果:

var invalidChars = Path.GetInvalidFileNameChars();

string invalidCharsRemoved = new string(stringWithInvalidChars
  .Where(x => !invalidChars.Contains(x))
  .ToArray());

我写这个怪物是为了好玩，它让你可以往返:

public static class FileUtility
{
    private const char PrefixChar = '%';
    private static readonly int MaxLength;
    private static readonly Dictionary<char,char[]> Illegals;
    static FileUtility()
    {
        List<char> illegal = new List<char> { PrefixChar };
        illegal.AddRange(Path.GetInvalidFileNameChars());
        MaxLength = illegal.Select(x => ((int)x).ToString().Length).Max();
        Illegals = illegal.ToDictionary(x => x, x => ((int)x).ToString("D" + MaxLength).ToCharArray());
    }

    public static string FilenameEncode(string s)
    {
        var builder = new StringBuilder();
        char[] replacement;
        using (var reader = new StringReader(s))
        {
            while (true)
            {
                int read = reader.Read();
                if (read == -1)
                    break;
                char c = (char)read;
                if(Illegals.TryGetValue(c,out replacement))
                {
                    builder.Append(PrefixChar);
                    builder.Append(replacement);
                }
                else
                {
                    builder.Append(c);
                }
            }
        }
        return builder.ToString();
    }

    public static string FilenameDecode(string s)
    {
        var builder = new StringBuilder();
        char[] buffer = new char[MaxLength];
        using (var reader = new StringReader(s))
        {
            while (true)
            {
                int read = reader.Read();
                if (read == -1)
                    break;
                char c = (char)read;
                if (c == PrefixChar)
                {
                    reader.Read(buffer, 0, MaxLength);
                    var encoded =(char) ParseCharArray(buffer);
                    builder.Append(encoded);
                }
                else
                {
                    builder.Append(c);
                }
            }
        }
        return builder.ToString();
    }

    public static int ParseCharArray(char[] buffer)
    {
        int result = 0;
        foreach (char t in buffer)
        {
            int digit = t - '0';
            if ((digit < 0) || (digit > 9))
            {
                throw new ArgumentException("Input string was not in the correct format");
            }
            result *= 10;
            result += digit;
        }
        return result;
    }
}

我创建了一个扩展方法，它结合了几个建议:

在哈希集中保存非法字符 过滤ascii 127以下的字符。因为路径。getinvalidfilenamecars不包括ascii码从0到255的所有无效字符。看这里和MSDN 定义替换字符的可能性

来源:

public static class FileNameCorrector
{
    private static HashSet<char> invalid = new HashSet<char>(Path.GetInvalidFileNameChars());

    public static string ToValidFileName(this string name, char replacement = '\0')
    {
        var builder = new StringBuilder();
        foreach (var cur in name)
        {
            if (cur > 31 && cur < 128 && !invalid.Contains(cur))
            {
                builder.Append(cur);
            }
            else if (replacement != '\0')
            {
                builder.Append(replacement);
            }
        }

        return builder.ToString();
    }
}

如果您必须在项目中的许多地方使用该方法，您还可以创建一个扩展方法，并在项目中的任何地方调用它来获取字符串。

 public static class StringExtension
    {
        public static string RemoveInvalidChars(this string originalString)
        {            
            string finalString=string.Empty;
            if (!string.IsNullOrEmpty(originalString))
            {
                return string.Concat(originalString.Split(Path.GetInvalidFileNameChars()));
            }
            return finalString;            
        }
    }

你可以这样调用上面的扩展方法:

string illegal = "\"M<>\"\\a/ry/ h**ad:>> a\\/:*?\"<>| li*tt|le|| la\"mb.?";
string afterIllegalChars = illegal.RemoveInvalidChars();

这样做会想要你想要的，避免碰撞

 static string SanitiseFilename(string key)
    {
        var invalidChars = Path.GetInvalidFileNameChars();
        var sb = new StringBuilder();
        foreach (var c in key)
        {
            var invalidCharIndex = -1;
            for (var i = 0; i < invalidChars.Length; i++)
            {
                if (c == invalidChars[i])
                {
                    invalidCharIndex = i;
                }
            }
            if (invalidCharIndex > -1)
            {
                sb.Append("_").Append(invalidCharIndex);
                continue;
            }

            if (c == '_')
            {
                sb.Append("__");
                continue;
            }

            sb.Append(c);
        }
        return sb.ToString();

    }