Question

用户可以拥有以下访问权限：

Read = 1
Create = 2
Edit = 4
Delete = 8
Publish = 16
Administer = 32

当访问权限保存在数据库中时，只有一个数字用于表示该用户的所有访问权限。

e.g。

3 = Read + Create
25 = Read + Delete + Publish

如何获取给定号码（访问掩码）的所有访问权限？

非常感谢任何帮助！

Answer 1

[Flags]
public enum MyFlags
{
    Read = 1,
    Create = 2,
    Edit = 4,
    Delete = 8,
    Publish = 16,
    Administer = 32,
}

申报

MyFlags readCreate = MyFlags.Read | MyFlags.Create;

测试

bool hasRead = (readCreate & MyFlags.Read) == MyFlags.Read;
bool hasEdit = (readCreate & MyFlags.Edit) == MyFlags.Edit;

Answer 2

var mask = (AccessRights)25;

var rightsForMask = Enum.GetValues(typeof(AccessRights))
                        .Cast<AccessRights>()
                        .Where(x => mask.HasFlag(x));

foreach (var right in rightsForMask)
{
    // displays "1:Read", "8:Delete", "16:Publish"
    Console.WriteLine((int)right + ":" + right);
}

// ...

[Flags]
public enum AccessRights
{
    Read = 1, Create = 2, Edit = 4, Delete = 8, Publish = 16, Administer = 32
}

如果您不使用.NET4，则HasFlag方法将不可用，在这种情况下，您需要将Where子句更改为Where(x => (mask & x) == x)。< / p>

如何从访问掩码中读取访问权限？

2 个答案: