在開發中,我們經常會使用IO操作,例如創建,刪除文件等操作。在項目中這樣的需求也較多,我們也會經常對這些操作進行編碼,但是對文件的權限進行設置,這樣的操作可能會手動操作,現在介紹一種采用代碼動態對文件設置權限的操作。
在對文件進行權限設置在DOtNet中,會采用FileSystemAccessRule類進行文件的權限操作。
1.現在看一下FileSystemAccessRule的實現代碼:
public FileSystemAccessRule( IdentityReference identity, FileSystemRights fileSystemRights, AccessControlType type ) : this( identity, AccessMaskFromRights( fileSystemRights, type ), false, InheritanceFlags.None, PropagationFlags.None, type ) { } public FileSystemAccessRule( String identity, FileSystemRights fileSystemRights, AccessControlType type ) : this( new NTAccount(identity), AccessMaskFromRights( fileSystemRights, type ), false, InheritanceFlags.None, PropagationFlags.None, type ) { } // // Constructor for creating access rules for folder objects // public FileSystemAccessRule( IdentityReference identity, FileSystemRights fileSystemRights, InheritanceFlags inheritanceFlags, PropagationFlags propagationFlags, AccessControlType type ) : this( identity, AccessMaskFromRights( fileSystemRights, type ), false, inheritanceFlags, propagationFlags, type ) { } public FileSystemAccessRule( String identity, FileSystemRights fileSystemRights, InheritanceFlags inheritanceFlags, PropagationFlags propagationFlags, AccessControlType type ) : this( new NTAccount(identity), AccessMaskFromRights( fileSystemRights, type ), false, inheritanceFlags, propagationFlags, type ) { } internal FileSystemAccessRule( IdentityReference identity, int accessMask, bool isInherited, InheritanceFlags inheritanceFlags, PropagationFlags propagationFlags, AccessControlType type ) : base( identity, accessMask, isInherited, inheritanceFlags, propagationFlags, type ) { } #endregion #region Public properties public FileSystemRights FileSystemRights { get { return RightsFromAccessMask( base.AccessMask ); } } internal static int AccessMaskFromRights( FileSystemRights fileSystemRights, AccessControlType controlType ) { if (fileSystemRights < (FileSystemRights) 0 || fileSystemRights > FileSystemRights.FullControl) throw new ArgumentOutOfRangeException("fileSystemRights", Environment.GetResourceString("Argument_InvalidEnumValue", fileSystemRights, "FileSystemRights")); Contract.EndContractBlock(); if (controlType == AccessControlType.Allow) { fileSystemRights |= FileSystemRights.Synchronize; } else if (controlType == AccessControlType.Deny) { if (fileSystemRights != FileSystemRights.FullControl && fileSystemRights != (FileSystemRights.FullControl & ~FileSystemRights.DeleteSubdirectoriesAndFiles)) fileSystemRights &= ~FileSystemRights.Synchronize; } return ( int )fileSystemRights; } internal static FileSystemRights RightsFromAccessMask( int accessMask ) { return ( FileSystemRights )accessMask; } }
2.由於FileSystemAccessRule繼承自AccessRule,現在看一下AccessRule的源碼:
/// <summary> /// 表示用戶的標識、訪問掩碼和訪問控制類型(允許或拒絕)的組合。<see cref="T:System.Security.AccessControl.AccessRule"/> 對象還包含有關子對象如何繼承規則以及如何傳播繼承的信息。 /// </summary> public abstract class AccessRule : AuthorizationRule { /// <summary> /// 使用指定的值初始化 <see cref="T:System.Security.AccessControl.AccessRule"/> 類的一個新實例。 /// </summary> /// <param name="identity">應用訪問規則的標識。此參數必須是可以強制轉換為 <see cref="T:System.Security.Principal.SecurityIdentifier"/> 的對象。</param><param name="accessMask">此規則的訪問掩碼。訪問掩碼是一個 32 位的匿名位集合,其含義是由每個集成器定義的。</param><param name="isInherited">如果此規則繼承自父容器,則為 true。</param><param name="inheritanceFlags">訪問規則的繼承屬性。</param><param name="propagationFlags">繼承的訪問規則是否自動傳播。如果 <paramref name="inheritanceFlags"/> 設置為 <see cref="F:System.Security.AccessControl.InheritanceFlags.None"/>,則將忽略傳播標志。</param><param name="type">有效的訪問控制類型。</param><exception cref="T:System.ArgumentException"><paramref name="identity"/> 參數的值不能強制轉換為 <see cref="T:System.Security.Principal.SecurityIdentifier"/>,或者 <paramref name="type"/> 參數包含無效值。</exception><exception cref="T:System.ArgumentOutOfRangeException"><paramref name="accessMask"/> 參數的值為零,或者 <paramref name="inheritanceFlags"/> 或 <paramref name="propagationFlags"/> 參數包含無法識別的標志值。</exception> protected AccessRule(IdentityReference identity, int accessMask, bool isInherited, InheritanceFlags inheritanceFlags, PropagationFlags propagationFlags, AccessControlType type); /// <summary> /// 獲取與此 <see cref="T:System.Security.AccessControl.AccessRule"/> 對象關聯的 <see cref="T:System.Security.AccessControl.AccessControlType"/> 對象。 /// </summary> /// /// <returns> /// 與此 <see cref="T:System.Security.AccessControl.AccessRule"/> 對象關聯的 <see cref="T:System.Security.AccessControl.AccessControlType"/> 對象。 /// </returns> public AccessControlType AccessControlType { get; } }
看來DotNet中實現文件權限設置的操作的類,現在提供幾個具體的文件設置操作代碼:
3.獲取目錄權限列表:
/// <summary> /// 獲取目錄權限列表 /// </summary> /// <param name="path">目錄的路徑。</param> /// <returns>指示目錄的權限列表</returns> public IList<FileSystemRights> GetDirectoryPermission(string path) { try { if (!DirectoryExists(path)) return null; IList<FileSystemRights> result = new List<FileSystemRights>(); var dSecurity = Directory.GetAccessControl(new DirectoryInfo(path).FullName); foreach (FileSystemAccessRule rule in dSecurity.GetAccessRules(true, true, typeof(NTAccount))) result.Add(rule.FileSystemRights); return result; } catch (Exception e) { throw new Exception(e.Message, e); } }
4.設置目錄權限
/// <summary> ///設置目錄權限 /// </summary> /// <param name="path">目錄的路徑。</param> /// <param name="permission">在目錄上設置的權限。</param> /// <returns>指示是否在目錄上應用權限的值。</returns> public bool SetDirectoryPermission(string path, FileSystemRights permission) { try { if (!DirectoryExists(path)) return false; var accessRule = new FileSystemAccessRule("Users", permission, InheritanceFlags.None, PropagationFlags.NoPropagateInherit, AccessControlType.Allow); var info = new DirectoryInfo(path); var security = info.GetAccessControl(AccessControlSections.Access); bool result; security.ModifyAccessRule(AccessControlModification.Set, accessRule, out result); if (!result) return false; const InheritanceFlags iFlags = InheritanceFlags.ContainerInherit | InheritanceFlags.ObjectInherit; accessRule = new FileSystemAccessRule("Users", permission, iFlags, PropagationFlags.InheritOnly, AccessControlType.Allow); security.ModifyAccessRule(AccessControlModification.Add, accessRule, out result); if (!result) return false; info.SetAccessControl(security); return true; } catch (Exception e) { throw new Exception(e.Message, e); } }
5.設置目錄權限列表
/// <summary> /// 設置目錄權限列表 /// </summary> /// <param name="path">目錄的路徑。</param> /// <param name="permissions">在目錄上設置的權限。</param> /// <returns>指示是否在目錄上應用權限的值。</returns> public bool SetDirectoryPermissions(string path, FileSystemRights[] permissions) { try { if (!DirectoryExists(path) || permissions == null || !permissions.Any()) return false; foreach (var permission in permissions) if (!SetDirectoryPermission(path, permission)) return false; return true; } catch (Exception e) { throw new Exception(e.Message, e); } }
以上是對文件權限設置操作的一個簡單介紹。