来自长位掩码的枚举值列表

Question

我们有一个通过位掩码来保护api控制器行为的应用程序。我想要做的是获取基于位掩码值的枚举列表。

下面是一个例子枚举：

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

    } 

我们通过将位并存储整数值创建权限。就像这样：

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); 
    } 

什么，我想做的就是基于整数值<T>值的列表。

我发现this，但它不会与位移位值工作：

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

Answer 1

你的问题是，你已经在DriverDataChange为int，而不是DriverChange定义的数据。

而是将它们定义是这样的：

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

然后你就可以对它们进行查询：

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

将返回：

CanAccess
CanView
MayPerformBaseFunctions

编辑：

如果有保持的DriverDataChange价值为int，那么您可以在检查丢掉。

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