我需要测试用户是否可以在实际尝试这样做之前写入文件夹。
我已经实现了以下方法(在c# 2.0中)，它尝试使用Directory.GetAccessControl()方法检索文件夹的安全权限。
private bool hasWriteAccessToFolder(string folderPath)
{
try
{
// Attempt to get a list of security permissions from the folder.
// This will raise an exception if the path is read only or do not have access to view the permissions.
System.Security.AccessControl.DirectorySecurity ds = Directory.GetAccessControl(folderPath);
return true;
}
catch (UnauthorizedAccessException)
{
return false;
}
}
当我在谷歌上搜索如何测试写访问权限时，没有这样的结果，而且在Windows中测试权限看起来非常复杂。我担心我过于简化了事情，这个方法并不健壮，尽管它似乎确实有效。
我测试当前用户是否具有写访问权限的方法是否正确?
这里的大多数答案都不检查写访问。它只是检查用户/组是否可以“读取权限”(读取文件/目录的ACE列表)。
此外，遍历ACE并检查它是否与安全标识符匹配也不起作用，因为用户可能是他可能获得/失去特权的组的成员。更糟糕的是嵌套组。
我知道这是一个旧的线程，但有一个更好的方式为任何人现在看。
如果用户具有Read Permission权限为，则可以使用Authz API检查有效访问。
https://learn.microsoft.com/en-us/windows/win32/secauthz/using-authz-api
https://learn.microsoft.com/en-us/windows/win32/secauthz/checking-access-with-authz-api
试试这个:
try
{
DirectoryInfo di = new DirectoryInfo(path);
DirectorySecurity acl = di.GetAccessControl();
AuthorizationRuleCollection rules = acl.GetAccessRules(true, true, typeof(NTAccount));
WindowsIdentity currentUser = WindowsIdentity.GetCurrent();
WindowsPrincipal principal = new WindowsPrincipal(currentUser);
foreach (AuthorizationRule rule in rules)
{
FileSystemAccessRule fsAccessRule = rule as FileSystemAccessRule;
if (fsAccessRule == null)
continue;
if ((fsAccessRule.FileSystemRights & FileSystemRights.WriteData) > 0)
{
NTAccount ntAccount = rule.IdentityReference as NTAccount;
if (ntAccount == null)
{
continue;
}
if (principal.IsInRole(ntAccount.Value))
{
Console.WriteLine("Current user is in role of {0}, has write access", ntAccount.Value);
continue;
}
Console.WriteLine("Current user is not in role of {0}, does not have write access", ntAccount.Value);
}
}
}
catch (UnauthorizedAccessException)
{
Console.WriteLine("does not have write access");
}
我试过大多数方法，但都是假阳性，都是出于同样的原因。仅仅测试目录是否有可用权限是不够的，您必须检查登录用户是否是具有该权限的组的成员。为此，您需要获取用户标识，并检查它是否是包含FileSystemAccessRule IdentityReference的组的成员。我已经测试过了，工作完美无缺..
/// <summary>
/// Test a directory for create file access permissions
/// </summary>
/// <param name="DirectoryPath">Full path to directory </param>
/// <param name="AccessRight">File System right tested</param>
/// <returns>State [bool]</returns>
public static bool DirectoryHasPermission(string DirectoryPath, FileSystemRights AccessRight)
{
if (string.IsNullOrEmpty(DirectoryPath)) return false;
try
{
AuthorizationRuleCollection rules = Directory.GetAccessControl(DirectoryPath).GetAccessRules(true, true, typeof(System.Security.Principal.SecurityIdentifier));
WindowsIdentity identity = WindowsIdentity.GetCurrent();
foreach (FileSystemAccessRule rule in rules)
{
if (identity.Groups.Contains(rule.IdentityReference))
{
if ((AccessRight & rule.FileSystemRights) == AccessRight)
{
if (rule.AccessControlType == AccessControlType.Allow)
return true;
}
}
}
}
catch { }
return false;
}
这应该是您所需要的全部内容，据我所知，您只需要捕获一个异常。
private static readonly byte[] TestArray = new byte[]{
69, 70, 71, 72
};
private static bool IsFolderAccessible(string path) {
var temp_path = Path.Combine(path, Path.GetRandomFileName());
try {
using (var file = File.Create(temp_path, TestArray.Length, FileOptions.DeleteOnClose)) {
file.Write(TestArray, 0, TestArray.Length);
}
return true;
} catch (UnauthorizedAccessException ex) {
Log.Warn($"Error accessing file {temp_path}", ex);
return false;
}
}
