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");
}

我知道现在写这篇文章有点晚了，但是您可能会发现这段代码很有用。

string path = @"c:\temp";
string NtAccountName = @"MyDomain\MyUserOrGroup";

DirectoryInfo di = new DirectoryInfo(path);
DirectorySecurity acl = di.GetAccessControl(AccessControlSections.All);
AuthorizationRuleCollection rules = acl.GetAccessRules(true, true, typeof(NTAccount));

//Go through the rules returned from the DirectorySecurity
foreach (AuthorizationRule rule in rules)
{
    //If we find one that matches the identity we are looking for
    if (rule.IdentityReference.Value.Equals(NtAccountName,StringComparison.CurrentCultureIgnoreCase))
    {
        var filesystemAccessRule = (FileSystemAccessRule)rule;

        //Cast to a FileSystemAccessRule to check for access rights
        if ((filesystemAccessRule.FileSystemRights & FileSystemRights.WriteData)>0 && filesystemAccessRule.AccessControlType != AccessControlType.Deny)
        {
            Console.WriteLine(string.Format("{0} has write access to {1}", NtAccountName, path));
        }
        else
        {
            Console.WriteLine(string.Format("{0} does not have write access to {1}", NtAccountName, path));
        }
    }
}

Console.ReadLine();

把它放到一个控制台应用程序中，看看它是否满足你的需要。

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

在代码中有一个潜在的竞争条件——如果用户在检查时拥有写入文件夹的权限，但在用户实际写入文件夹之前，该权限被撤销，会发生什么情况?写入操作将抛出一个异常，您需要捕获并处理该异常。所以最初的检查是没有意义的。您也可以只执行写入并处理任何异常。这是你的情况的标准模式。

public bool IsDirectoryWritable(string dirPath, bool throwIfFails = false)
{
    try
    {
        using (FileStream fs = File.Create(
            Path.Combine(
                dirPath, 
                Path.GetRandomFileName()
            ), 
            1,
            FileOptions.DeleteOnClose)
        )
        { }
        return true;
    }
    catch
    {
        if (throwIfFails)
            throw;
        else
            return false;
    }
}

仅仅尝试访问有问题的文件是不够的。测试将在运行程序的用户的权限下运行——这并不一定是您想要测试的用户权限。