System.IO命名空间中是否有一个检查文件名有效性的方法？
例如，C:\foo\bar会验证，而:"~-*则不会
或者有点棘手，X:\foo\bar会验证系统上是否有X:驱动器，否则不会。
我想我自己可以编写这样的方法，但我对内置的方法更感兴趣。
答案 0 :(得分：88)
只是做;
System.IO.FileInfo fi = null;
try {
fi = new System.IO.FileInfo(fileName);
}
catch (ArgumentException) { }
catch (System.IO.PathTooLongException) { }
catch (NotSupportedException) { }
if (ReferenceEquals(fi, null)) {
// file name is not valid
} else {
// file name is valid... May check for existence by calling fi.Exists.
}
为了创建FileInfo实例，文件不需要存在。
答案 1 :(得分：33)
正如jberger所指出的，还有一些其他字符未包含在此方法的响应中。有关Windows平台的更多详细信息，请查看MSDN上的Naming Files, Paths and Namespaces，
作为Micah points out，有Directory.GetLogicalDrives来获取有效驱动器列表。
答案 2 :(得分：9)
System.IO名称空间中存在多种可以使用的方法：
Directory.GetLogicalDrives() // Returns an array of strings like "c:\"
Path.GetInvalidFileNameChars() // Returns an array of characters that cannot be used in a file name
Path.GetInvalidPathChars() // Returns an array of characters that cannot be used in a path.
根据建议你可以这样做：
bool IsValidFilename(string testName) {
string regexString = "[" + Regex.Escape(Path.GetInvalidPathChars()) + "]";
Regex containsABadCharacter = new Regex(regexString);
if (containsABadCharacter.IsMatch(testName)) {
return false;
}
// Check for drive
string pathRoot = Path.GetPathRoot(testName);
if (Directory.GetLogicalDrives().Contains(pathRoot)) {
// etc
}
// other checks for UNC, drive-path format, etc
return true;
}
答案 3 :(得分：9)
您可以使用System.Uri类。 Uri类不仅对Web URL有用，它还处理文件系统路径。使用Uri.TryCreate方法查找路径是否为root，然后使用IsLoopback属性确定Uri是否引用本地计算机。
这是一个简单的方法，用于确定字符串是否为有效，本地和根文件路径。
public bool IsPathValidRootedLocal(String pathString) {
Uri pathUri;
Boolean isValidUri = Uri.TryCreate(pathString, UriKind.Absolute, out pathUri);
return isValidUri && pathUri != null && pathUri.IsLoopback;
}
我相信这会奏效。
答案 4 :(得分：5)
即使文件名有效，您仍可能希望touch确保用户有权写入。
如果你不会在短时间内用数百个文件颠倒磁盘，我认为创建一个空文件是一种合理的方法。
如果你真的想要更轻松的东西，比如检查无效的字符，那么将你的文件名与Path.GetInvalidFileNameChars（）进行比较。
答案 5 :(得分：3)
以为我会发布一个解决方案，我在寻找相同问题的稳健解决方案之后，从我找到的一些答案拼凑而成。希望它可以帮助别人。
using System;
using System.IO;
//..
public static bool ValidateFilePath(string path, bool RequireDirectory, bool IncludeFileName, bool RequireFileName = false)
{
if (string.IsNullOrEmpty(path)) { return false; }
string root = null;
string directory = null;
string filename = null;
try
{
// throw ArgumentException - The path parameter contains invalid characters, is empty, or contains only white spaces.
root = Path.GetPathRoot(path);
// throw ArgumentException - path contains one or more of the invalid characters defined in GetInvalidPathChars.
// -or- String.Empty was passed to path.
directory = Path.GetDirectoryName(path);
// path contains one or more of the invalid characters defined in GetInvalidPathChars
if (IncludeFileName) { filename = Path.GetFileName(path); }
}
catch (ArgumentException)
{
return false;
}
// null if path is null, or an empty string if path does not contain root directory information
if (String.IsNullOrEmpty(root)) { return false; }
// null if path denotes a root directory or is null. Returns String.Empty if path does not contain directory information
if (String.IsNullOrEmpty(directory)) { return false; }
if (RequireFileName)
{
// if the last character of path is a directory or volume separator character, this method returns String.Empty
if (String.IsNullOrEmpty(filename)) { return false; }
// check for illegal chars in filename
if (filename.IndexOfAny(Path.GetInvalidFileNameChars()) >= 0) { return false; }
}
return true;
}
答案 6 :(得分：2)
使用GetInvalidFileNameChars method中Path class上的静态System.IO namespace来确定文件名中哪些字符是非法的。
要在路径中执行此操作，请在同一个类上调用静态GetInvalidPathChars method。
要确定路径的根是否有效，您可以调用Path类上的静态GetPathRoot method来获取根，然后使用Directory class确定它是否为有效。然后，您可以正常验证路径的其余部分。
答案 7 :(得分：2)
如果路径或文件名无效，则有几个System.IO.Path方法会抛出异常：
http://msdn.microsoft.com/en-us/library/system.io.path_methods.aspx
答案 8 :(得分：2)
尝试使用此方法，尝试涵盖所有可能的异常方案。它适用于几乎所有与Windows相关的路径。
/// <summary>
/// Validate the Path. If path is relative append the path to the project directory by default.
/// </summary>
/// <param name="path">Path to validate</param>
/// <param name="RelativePath">Relative path</param>
/// <param name="Extension">If want to check for File Path</param>
/// <returns></returns>
private static bool ValidateDllPath(ref string path, string RelativePath = "", string Extension = "") {
// Check if it contains any Invalid Characters.
if (path.IndexOfAny(Path.GetInvalidPathChars()) == -1) {
try {
// If path is relative take %IGXLROOT% as the base directory
if (!Path.IsPathRooted(path)) {
if (string.IsNullOrEmpty(RelativePath)) {
// Exceptions handled by Path.GetFullPath
// ArgumentException path is a zero-length string, contains only white space, or contains one or more of the invalid characters defined in GetInvalidPathChars. -or- The system could not retrieve the absolute path.
//
// SecurityException The caller does not have the required permissions.
//
// ArgumentNullException path is null.
//
// NotSupportedException path contains a colon (":") that is not part of a volume identifier (for example, "c:\").
// PathTooLongException The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters, and file names must be less than 260 characters.
// RelativePath is not passed so we would take the project path
path = Path.GetFullPath(RelativePath);
} else {
// Make sure the path is relative to the RelativePath and not our project directory
path = Path.Combine(RelativePath, path);
}
}
// Exceptions from FileInfo Constructor:
// System.ArgumentNullException:
// fileName is null.
//
// System.Security.SecurityException:
// The caller does not have the required permission.
//
// System.ArgumentException:
// The file name is empty, contains only white spaces, or contains invalid characters.
//
// System.IO.PathTooLongException:
// The specified path, file name, or both exceed the system-defined maximum
// length. For example, on Windows-based platforms, paths must be less than
// 248 characters, and file names must be less than 260 characters.
//
// System.NotSupportedException:
// fileName contains a colon (:) in the middle of the string.
FileInfo fileInfo = new FileInfo(path);
// Exceptions using FileInfo.Length:
// System.IO.IOException:
// System.IO.FileSystemInfo.Refresh() cannot update the state of the file or
// directory.
//
// System.IO.FileNotFoundException:
// The file does not exist.-or- The Length property is called for a directory.
bool throwEx = fileInfo.Length == -1;
// Exceptions using FileInfo.IsReadOnly:
// System.UnauthorizedAccessException:
// Access to fileName is denied.
// The file described by the current System.IO.FileInfo object is read-only.-or-
// This operation is not supported on the current platform.-or- The caller does
// not have the required permission.
throwEx = fileInfo.IsReadOnly;
if (!string.IsNullOrEmpty(Extension)) {
// Validate the Extension of the file.
if (Path.GetExtension(path).Equals(Extension, StringComparison.InvariantCultureIgnoreCase)) {
// Trim the Library Path
path = path.Trim();
return true;
} else {
return false;
}
} else {
return true;
}
} catch (ArgumentNullException) {
// System.ArgumentNullException:
// fileName is null.
} catch (System.Security.SecurityException) {
// System.Security.SecurityException:
// The caller does not have the required permission.
} catch (ArgumentException) {
// System.ArgumentException:
// The file name is empty, contains only white spaces, or contains invalid characters.
} catch (UnauthorizedAccessException) {
// System.UnauthorizedAccessException:
// Access to fileName is denied.
} catch (PathTooLongException) {
// System.IO.PathTooLongException:
// The specified path, file name, or both exceed the system-defined maximum
// length. For example, on Windows-based platforms, paths must be less than
// 248 characters, and file names must be less than 260 characters.
} catch (NotSupportedException) {
// System.NotSupportedException:
// fileName contains a colon (:) in the middle of the string.
} catch (FileNotFoundException) {
// System.FileNotFoundException
// The exception that is thrown when an attempt to access a file that does not
// exist on disk fails.
} catch (IOException) {
// System.IO.IOException:
// An I/O error occurred while opening the file.
} catch (Exception) {
// Unknown Exception. Might be due to wrong case or nulll checks.
}
} else {
// Path contains invalid characters
}
return false;
}
答案 9 :(得分：1)
我不知道任何可以为您验证所有内容的开箱即用的内容，但Path中的.NET课程可以为您提供极大的帮助。
对于初学者来说，它有：
char[] invalidChars = Path.GetInvalidFileNameChars(); //returns invalid charachters
或：
Path.GetPathRoot(string); // will return the root.
答案 10 :(得分：1)
我很幸运使用正则表达式，正如其他人所表现的那样。
要记住的一件事是，Windows至少禁止某些文件名，否则这些文件名包含法律字符。一些人想到：com，nul，prn。
我现在没有它，但我有一个正则表达式，考虑到这些文件名。如果你想我可以发布它，否则我相信你可以像我一样找到它：谷歌。
-Jay
答案 11 :(得分：0)
可能最好的方法是在文件系统上构建一个混合正则表达式和小查找组合的自定义方法（例如，查看驱动器）
答案 12 :(得分：0)
这将为您提供机器上的驱动器：
System.IO.DriveInfo.GetDrives()
这两种方法会让你检查不好的字符：
System.IO.Path.GetInvalidFileNameChars();
System.IO.Path.GetInvalidPathChars();
答案 13 :(得分：0)
认为现在回答太晚了但是...... :) 如果是带有卷名的路径，你可以这样写：
using System;
using System.Linq;
using System.IO;
// ...
var drives = Environment.GetLogicalDrives();
var invalidChars = Regex.Replace(new string(Path.GetInvalidFileNameChars()), "[\\\\/]", "");
var drive = drives.FirstOrDefault(d => filePath.StartsWith(d));
if (drive != null) {
var fileDirPath = filePath.Substring(drive.Length);
if (0 < fileDirPath.Length) {
if (fileDirPath.IndexOfAny(invalidChars.ToCharArray()) == -1) {
if (Path.Combine(drive, fileDirPath) != drive) {
// path correct and we can proceed
}
}
}
}