长位掩码的枚举值列表

本文关键字：列表 枚举 掩码 | 更新日期: 2023-09-27 18:18:09

我们有一个通过位掩码保护api控制器动作的应用程序。我要做的是获得基于位掩码值的枚举列表。

下面是一个示例Enum:

    [Flags]
    public enum DriverChange : long
    {
        CanAccess = 1 << 0,
        CanView = 1 << 1,
        CanUpdate = 1 << 2,
        MayPerformBaseFunctions = 1 << 3,
        CanAddPool = 1 << 4,
        CanModifyPool = 1 << 5,
    }

通过添加位并存储整数值来创建权限。这样的:

public class DriverDataChange
    {
        public const int None = 0;
        public const int View = (int)(Permissions.DriverDataChange.CanAccess |
                                                Permissions.DriverDataChange.CanView |
                                                Permissions.DriverDataChange.MayPerformBaseFunctions);
        public const int MassUpload = (int)(Permissions.DriverDataChange.CanAccess |
                                                Permissions.DriverDataChange.CanView |
                                                Permissions.DriverDataChange.CanUpdate |
                                                Permissions.DriverDataChange.MayPerformBaseFunctions |
                                                Permissions.DriverDataChange.CanPerformMassUpload);
        public const int FullNoMassUpload = (int)(Permissions.DriverDataChange.CanAccess |
                                                Permissions.DriverDataChange.CanView |
                                                Permissions.DriverDataChange.CanUpdate |
                                                Permissions.DriverDataChange.MayPerformBaseFunctions |
                                                Permissions.DriverDataChange.CanAddPool |
                                                Permissions.DriverDataChange.CanModifyPool |
                                                Permissions.DriverDataChange.CanAddDriver |
                                                Permissions.DriverDataChange.CanModifyDriver |
                                                Permissions.DriverDataChange.CanUnassignVehicle |
                                                Permissions.DriverDataChange.CanCloneVehicleDetails |
                                                Permissions.DriverDataChange.CanModifyVehicleClientDataFields);
        public const int Full = (int)(Permissions.DriverDataChange.CanAccess |
                                                Permissions.DriverDataChange.CanView |
                                                Permissions.DriverDataChange.CanUpdate |
                                                Permissions.DriverDataChange.MayPerformBaseFunctions |
                                                Permissions.DriverDataChange.CanAddPool |
                                                Permissions.DriverDataChange.CanModifyPool |
                                                Permissions.DriverDataChange.CanAddDriver |
                                                Permissions.DriverDataChange.CanModifyDriver |
                                                Permissions.DriverDataChange.CanUnassignVehicle |
                                                Permissions.DriverDataChange.CanCloneVehicleDetails |
                                                Permissions.DriverDataChange.CanModifyVehicleClientDataFields |
                                                Permissions.DriverDataChange.CanPerformMassUpload);
    }

我想做的是根据整数值获得<T>值的列表。

我发现了这个，但它不适用于位移位值:

List<Permissions.DriverDataChange> permissionDetails =Enum.GetValues(typeof(Permissions.DriverDataChange))
                                                .Cast<Enum>()
                                                .Where(m => DriverDataChange.Full.HasFlag(m))
                                                .Cast<Permissions.DriverDataChange>();

长位掩码的枚举值列表

您的问题是您已将DriverDataChange中的数据定义为int而不是DriverChange。

而是这样定义它们:

public const DriverDataChange View = (DriverDataChange.CanAccess |
                                         DriverDataChange.CanView |
                                         DriverDataChange.MayPerformBaseFunctions);

然后你可以查询它们:

var permissionDetails = Enum.GetValues(typeof(DriverDataChange)).Cast<DriverDataChange>()
                             .Where(m => DriverDataChangeData.View.HasFlag(m));

返回:

CanAccess
CanView
MayPerformBaseFunctions

编辑:

如果您有保持DriverDataChange的值为int，那么您可以在检查中强制转换它们:

var permissionDetails = Enum.GetValues(typeof(DriverDataChange)).Cast<DriverDataChange>()
                   .Where(m => ((DriverDataChange)DriverDataChangeData.View).HasFlag(m));

我是这样做的

var permissionDetails = 
            Enum.GetValues(typeof(DriverDataChange))
           .Cast<int>()
           .Where(m => (DriverDataChangeData.View & m) > 0)
           .Cast<DriverDataChange>();
我还写了一个扩展 
    public static class EnumExtensions
    {
        public static IEnumerable<T> UnfoldBitmask<T>(int bitMask)
        {
            return Enum.GetValues(typeof(T)).Cast<int>().Where(m => (bitMask & m) > 0).Cast<T>();
        }
    }

你可以这样调用

int permissionDetails = EnumExtensions.UnfoldBitmask<DriverDataChange>(DriverDataChangeData.View );
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