VB.NET动态工厂

Question

如何更改此代码以使工厂成为动态的。我相信我已经很熟悉远程处理了。我不想要工厂的任何硬编码，也不想重新编译。数据库驱动它。

Dim genericRule As Rule
Dim factoryObject As String

factoryObject = _dal.GetFactoryObject(ruleId)

'Close, but not quite will keep working on it.
'Dynamic object creation using remoting to the local computer.
'Dim mArgs(1) As Object
'mArgs(0) = ruleid
'mArgs(1) = pronumber
'Dim mObj As Object
'Try
'    mObj = Activator.CreateInstance(Nothing, "DedicatedBilling.RuleFactory." + mFactoryObject, mArgs)
'    mRule = CType(mObj, Rule)
'Catch ex As Exception
'    mObj = Activator.CreateInstance(Nothing, "DedicatedBilling.RuleFactory.ErrorRule", mArgs)
'    mRule = CType(mObj, Rule)
'End Try

Select Case factoryObject
    Case "DeadHeadEntryRule"
        genericRule = New DeadHeadEntryRule(ruleId, proNumber)
    Case "DeadHeadFuelRateRule"
        genericRule = New DeadHeadFuelRateRule(ruleId, proNumber)
    Case "DeliveryStatusRule"
        genericRule = New DeliveryStatusRule(ruleId, proNumber)

    Case Else
        genericRule = New ErrorRule(ruleId, proNumber)
End Select

Answer 1

请不要张贴这么多代码。一开始我甚至没有看到你的代码的重要部分。你不需要列出每一条规则来表达你的观点。

在任何情况下，您都希望查看Activator.CreateInstanceFrom和反射，而不是远程处理。

' Create an instance of the SomeType class that is defined in this assembly.
Dim oh As System.Runtime.Remoting.ObjectHandle = _
    Activator.CreateInstanceFrom(Assembly.GetEntryAssembly().CodeBase, _
                                 GetType(SomeType).FullName)

' Call an instance method defined by the SomeType type using this object.
Dim st As SomeType = CType(oh.Unwrap(), SomeType)

st.DoSomething(5)