作者:slightboy,时间:2006-10-14
首发于:http://cs.alienwave.cn/Topic/329.aspx

看到好多同学权限判断都是用字符串然后或分割或截取
其实对于允许/不允许(true/false)这种的权限,用逻辑运算再恰当不过了
声明下:本文针对入门和为掌握的同学,如果已经懂了那可以无视了
可能意思表达的不是很清楚,敬请原谅.

逻辑运算符介绍:
And:逻辑与
0And0=0
0And1=0
1And0=0
1And1=1
Or:逻辑或
0Or0=0
0Or1=1
1Or0=1
1Or1=1
Xor:异或
0Xor0=1
0Xor1=1
1Xor0=1
1Xor1=1
Not:逻辑非
Not1=0
Not0=1

表达方式介绍:
1表示ture,0表示false
举二位为例
第一位表示Read的权限,第二位表示Write的权限,可以表示一下四种权限
00Read(false)Write(false)
01Read(true)Write(false)
10Read(false)Write(true)
11Read(true)Write(true)

运算方式介绍:
还是继续上面的例子
Read=01(1),Write=10(2)
00(0)AndRead=0
01(1)AndRead=Read
10(2)AndRead=0
11(3)AndRead=Read
00(0)AndWrite=0
01(1)AndWrite=0
10(2)AndWrite=Write
11(3)AndWrite=Write

下面给出示例代码:
权限定义类(要有枚举类型该多好啊...)
ClassPermissionTypePublicReadPublicWritePublicDeletePrivateSubClass_InitializeRead=1Write=2Delete=4EndSubEndClass
权限类
ClassPermissionSetComponentPrivateintValuePublicPropertyGetRead()Read=GetValue(Permission.Read)EndPropertyPublicPropertyLetRead(arg)CallSetValue(Permission.Read,arg)EndPropertyPublicPropertyGetWrite()Write=GetValue(Permission.Write)EndPropertyPublicPropertyLetWrite(arg)CallSetValue(Permission.Write,arg)EndPropertyPublicPropertyGetDelete()Delete=GetValue(Permission.Delete)EndPropertyPublicPropertyLetDelete(arg)CallSetValue(Permission.Delete,arg)EndPropertyPublicPropertyGetValue()Value=intValueEndPropertyPublicPropertyLetValue(arg)intValue=argEndPropertyPublicFunctionGetValue(intType)GetValue=(ValueandintType)=intTypeEndFunctionPublicSubSetValue(intType,boolValue)IF(boolValue)ThenValue=ValueOrintTypeElseValue=ValueAnd(NotintType)EndIFEndSubEndClass
运用示例代码:
DimPermission:SetPermission=newPermissionTypeDimPermissionSet:SetPermissionSet=newPermissionSetComponentPermissionSet.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)Functionw(o)Response.Write("<br/>"&o)EndFunction

今天的课程就到这里,大家可以举一反三,下课...