基于邏輯運算的簡單權限系統(原理,設計,實現) VBS 版
2019-10-26 17:58:38
供稿：網友
作者:slightboy
看到好多同學權限判斷都是用字符串 然后或分割或截取
其實對于 允許/不允許(true/false) 這種的權限, 用邏輯運算再恰當不過了
聲明下: 本文針對入門和為掌握的同學, 如果已經懂了那可以無視了
可能意思表達的不是很清楚, 敬請原諒.
邏輯運算符介紹:
And: 邏輯與
0 And 0 = 0
0 And 1 = 0
1 And 0 = 0
1 And 1 = 1
Or: 邏輯或
0 Or 0 = 0
0 Or 1 = 1
1 Or 0 = 1
1 Or 1 = 1
Xor: 異或
0 Xor 0 = 0
0 Xor 1 = 1
1 Xor 0 = 1
1 Xor 1 = 0
Not: 邏輯非
Not 1 = 0
Not 0 = 1
表達方式介紹:
1 表示 ture, 0 表示 false
舉二位為例
第一位 表示 Read 的權限, 第二位 表示 Write 的權限, 可以表示一下四種權限
00 Read(false) Write(false)
01 Read(true) Write(false)
10 Read(false) Write(true)
11 Read(true) Write(true)
運算方式介紹:
還是繼續上面的例子
Read = 01(1), Write = 10(2)
00(0) And Read = 0
01(1) And Read = Read
10(2) And Read = 0
11(3) And Read = Read
00(0) And Write = 0
01(1) And Write = 0
10(2) And Write = Write
11(3) And Write = Write
下面給出示例代碼:
權限定義類(要有枚舉類型該多好啊...)
Class PermissionType
Public Read
Public Write
Public Delete
Private Sub Class_Initialize
Read = 1
Write = 2
Delete = 4
End Sub
End Class
權限類
Class PermissionSetComponent
Private intValue
Public Property Get Read()
Read = GetValue(Permission.Read)
End Property
Public Property Let Read(arg)
Call SetValue(Permission.Read, arg)
End Property
