基于邏輯運算的簡單權限系統(原理,設計,實現) VBS 版
2020-07-26 12:04:22
供稿：網友
作者: slightboy, 時間: 2006-10-14
首發于: http://cs.alienwave.cn/Topic/329.aspx
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 = 1
0 Xor 1 = 1
1 Xor 0 = 1
1 Xor 1 = 1
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 PermissionTypePublic ReadPublic WritePublic DeletePrivate Sub Class_InitializeRead = 1Write = 2Delete = 4End SubEnd Class
權限類
Class PermissionSetComponentPrivate intValuePublic Property Get Read()Read = GetValue(Permission.Read)End PropertyPublic Property Let Read(arg)Call SetValue(Permission.Read, arg)End PropertyPublic Property Get Write()Write = GetValue(Permission.Write)End PropertyPublic Property Let Write(arg)Call SetValue(Permission.Write, arg)End PropertyPublic Property Get Delete()Delete = GetValue(Permission.Delete)End PropertyPublic Property Let Delete(arg)Call SetValue(Permission.Delete, arg)End PropertyPublic Property Get Value()Value = intValueEnd PropertyPublic Property Let Value(arg)intValue = argEnd PropertyPublic Function GetValue(intType)GetValue = (Value and intType) = intTypeEnd FunctionPublic Sub SetValue(intType, boolValue)IF (boolValue) ThenValue = Value Or intTypeElseValue = Value And (Not intType)End IFEnd SubEnd Class
運用示例代碼:
Dim Permission : Set Permission = new PermissionTypeDim PermissionSet : Set PermissionSet = new PermissionSetComponentPermissionSet.Value = 0w("Read:")PermissionSet.Read = falsew(PermissionSet.Value &" "& PermissionSet.Read)PermissionSet.Read = truew(PermissionSet.Value &" "& PermissionSet.Read)w("Write:")PermissionSet.Write = falsew(PermissionSet.Value &" "& PermissionSet.Write)PermissionSet.Write = truew(PermissionSet.Value &" "& PermissionSet.Write)w("Delete:")PermissionSet.Delete = falsew(PermissionSet.Value &" "& PermissionSet.Delete)PermissionSet.Delete = truew(PermissionSet.Value &" "& PermissionSet.Delete)Function w(o)Response.Write("<br />"& o)End Function
今天的課程就到這里, 大家可以舉一反三, 下課...
