namespace Microsoft.SharePoint{    using System;    using System.Text;    using System.Collections.Generic;    using System.Linq;    using Microsoft.SharePoint;    public static class PermissionManager    {        //SPGroup group = web.Groups[0];         //SPUser user = web.Users[0];         //SPUser user2 = web.EnsureUser("mangaldas.mano");         //SPUser user3 = web.EnsureUser("Domain Users");         //SPPrincipal[] principals = { group, user, user2, user3 };         #region Adding Permissions to an item        /// <summary>        /// Set Permissions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="user">SPUser</param>        /// <param name="roleType">SPRoleType</param>        public static void SetPermissions(SPListItem item, SPUser user, SPRoleType roleType)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType);                SetPermissions(item, (SPPrincipal)user, roleDefinition);            }        }        public static void SetPermissions(SPListItem item, SPUser user, string rolename)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions[rolename];                if (roleDefinition != null)                    SetPermissions(item, (SPPrincipal)user, roleDefinition);            }        }        public static void SetPermissions(SPListItem item, string groupName, string rolename)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions[rolename];                SPGroup group = item.Web.Groups[groupName];                if (roleDefinition != null && group != null)                    SetPermissions(item, (SPPrincipal)group, roleDefinition);            }        }        public static void SetPermissions(SPListItem item, string groupName, SPRoleType roleType)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType);                SPGroup group = item.Web.Groups[groupName];                if (group != null)                    SetPermissions(item, (SPPrincipal)group, roleDefinition);            }        }        /// <summary>        /// Set Permissions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="principals">IEnumerable</param>        /// <param name="roleType">SPRoleType</param>        public static void SetPermissions(SPListItem item, IEnumerable<SPPrincipal> principals, SPRoleType roleType)        {            if (item != null)            {                foreach (SPPrincipal principal in principals)                {                    SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType);                    SetPermissions(item, principal, roleDefinition);                }            }        }        /// <summary>        /// Set Permissions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="principal">SPPrincipal</param>        /// <param name="roleType">SPRoleType</param>        public static void SetPermissions(SPListItem item, SPPrincipal principal, SPRoleType roleType)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType);                SetPermissions(item, principal, roleDefinition);            }        }        /// <summary>        /// Set Permissions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="user">SPUser</param>        /// <param name="roleDefinition">SPRoleDefinition</param>        public static void SetPermissions(SPListItem item, SPUser user, SPRoleDefinition roleDefinition)        {            if (item != null)            {                SetPermissions(item, (SPPrincipal)user, roleDefinition);            }        }        /// <summary>        /// Set Permissions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="principal">SPPrincipal</param>        /// <param name="roleDefinition">SPRoleDefinition</param>        public static void SetPermissions(SPListItem item, SPPrincipal principal, SPRoleDefinition roleDefinition)        {            if (item != null)            {                SPRoleAssignment roleAssignment = new SPRoleAssignment(principal);                roleAssignment.RoleDefinitionBindings.Add(roleDefinition);                item.RoleAssignments.Add(roleAssignment);            }        }        #endregion        #region Deleting all user Permissions from an item        /// <summary>        /// remove permisions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="user">SPUser</param>        public static void RemovePermissions(SPListItem item, SPUser user)        {            if (item != null)            {                RemovePermissions(item, user as SPPrincipal);            }        }        public static void RemovePermissions(SPListItem item, string groupName)        {            if (item != null)            {                SPGroup group = item.Web.Groups[groupName];                if (group != null)                    RemovePermissions(item, group as SPPrincipal);            }        }        /// <summary>        /// remove permisions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="principal">SPPrincipal</param>        public static void RemovePermissions(SPListItem item, SPPrincipal principal)        {            if (item != null)            {                item.RoleAssignments.Remove(principal);                // item.SystemUpdate();            }        }        #endregion        #region Removing specific roles from an item        /// <summary>        /// remove permission        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="principal">SPPrincipal</param>        /// <param name="roleDefinition">SPRoleDefinition</param>        public static void RemovePermissionsSpecificRole(SPListItem item, SPPrincipal principal, SPRoleDefinition roleDefinition)        {            if (item != null)            {                SPRoleAssignment roleAssignment = item.RoleAssignments.GetAssignmentByPrincipal(principal);                if (roleAssignment != null)                {                    if (roleAssignment.RoleDefinitionBindings.Contains(roleDefinition))                    {                        roleAssignment.RoleDefinitionBindings.Remove(roleDefinition);                        roleAssignment.Update();                    }                }            }        }        /// <summary>        /// remove permission        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="principal">SPPrincipal</param>        /// <param name="roleType">SPRoleType</param>        public static void RemovePermissionsSpecificRole(SPListItem item, SPPrincipal principal, SPRoleType roleType)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType);                RemovePermissionsSpecificRole(item, principal, roleDefinition);            }        }        public static void RemovePermissionsSpecificRole(SPListItem item, SPUser user, string roleName)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions[roleName];                if (roleDefinition != null)                    RemovePermissionsSpecificRole(item, user as SPPrincipal, roleDefinition);            }        }        public static void RemovePermissionsSpecificRole(SPListItem item, string groupName, string roleName)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions[roleName];                SPGroup group = item.Web.Groups[groupName];                if (group != null && roleDefinition != null)                    RemovePermissionsSpecificRole(item, group as SPPrincipal, roleDefinition);            }        }        #endregion        #region Updating or Modifying Permissions on an item        /// <summary>        /// modify Permissions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="principal">SPPrincipal</param>        /// <param name="roleType">SPRoleType</param>        public static void ChangePermissions(SPListItem item, SPPrincipal principal, SPRoleType roleType)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions.GetByType(roleType);                ChangePermissions(item, principal, roleDefinition);            }        }        public static void ChangePermissions(SPListItem item, SPUser user, string roleName)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions[roleName];                if (roleDefinition!=null)                ChangePermissions(item, user as SPPrincipal, roleDefinition);            }        }        public static void ChangePermissions(SPListItem item, string groupName, string roleName)        {            if (item != null)            {                SPRoleDefinition roleDefinition = item.Web.RoleDefinitions[roleName];                SPGroup group = item.Web.Groups[groupName];                if (roleDefinition != null)                    ChangePermissions(item, group as SPPrincipal, roleDefinition);            }        }        /// <summary>        /// modify Permissions        /// </summary>        /// <param name="item">SPListItem</param>        /// <param name="principal">SPPrincipal</param>        /// <param name="roleDefinition">SPRoleDefinition</param>        public static void ChangePermissions(SPListItem item, SPPrincipal principal, SPRoleDefinition roleDefinition)        {            SPRoleAssignment roleAssignment = item.RoleAssignments.GetAssignmentByPrincipal(principal);            if (roleAssignment != null)            {                roleAssignment.RoleDefinitionBindings.RemoveAll();                roleAssignment.RoleDefinitionBindings.Add(roleDefinition);                roleAssignment.Update();            }        }        #endregion        public static void BreakRoleSPListItem(SPListItem item)        {            if (item.HasUniqueRoleAssignments)            {                item.ResetRoleInheritance();            }            item.BreakRoleInheritance(false);        }        public static SPUser GetSPUserFromSPListItemByFieldName(SPListItem spItem, string fieldName)        {            string userName = spItem[fieldName].ToString();            SPFieldUser _user = (SPFieldUser)spItem.Fields[fieldName];            SPFieldUserValue userValue = (SPFieldUserValue)_user.GetFieldValue(userName);            return userValue.User;        }     }}