Question

我在使用vb代码dom时遇到了困难。基本上，我想动态编译这段代码：

Imports System    
Imports System.Collections.Generic
Imports Microsoft.VisualBasic
Namespace Formula

Public Class TsCalculator

Public Sub New()

End Sub

Public Shared Function Evaluate(ByVal Ts As Dictionary(Of String, Decimal)) As decimal

Dim result = If((Ts("sss")+Ts("zzz")) <> 0, (Ts("KWHD") - Ts("zzzz"))*Ts("sdsd")/(Ts("sds")+Ts("1ANGAT_M-DISPATCH")), (Ts("sdsd") - Ts("sdsd"))*(.5D + .5D))

Return result

End Function

End Class

End Namespace

为了编译这段代码，我使用了这个函数：

 Public Shared Function CompileCode(ByVal classname As String _

, ByVal inputname As String, _

ByVal compiler As CodeDomProvider, _

ByVal snippetcode As String) As Calculator(Of Decimal, Decimal)

Dim compilerargs = New CompilerParameters()

Dim code = BuildCodeString("Solver", inputname, snippetcode)

Dim currassembly = Reflection.Assembly.GetAssembly(GetType(FormulaCompiler))

With compilerargs

.TreatWarningsAsErrors = False

.ReferencedAssemblies.Add("System.dll")

.GenerateInMemory = True

.WarningLevel = 4

End With

Dim ss As Func(Of Dictionary(Of String, Decimal), Decimal)

Dim compiledresults = compiler.CompileAssemblyFromSource(compilerargs, code)

With compiledresults

If .Errors.HasErrors Then

Throw New InvalidExpressionException()

Else

Dim inputtypes = New Type() {GetType(Dictionary(Of String, Decimal))}

Dim formss = compiledresults.CompiledAssembly.GetType(String.Format("Formula.{0}", "Solver"))

Dim evalinfo = formss.GetMethod("Evaluate", inputtypes)

ss = CType([Delegate].CreateDelegate(GetType(Func(Of Dictionary(Of String, Decimal), Decimal)) _

, evalinfo), Func(Of Dictionary(Of String, Decimal), Decimal))

End If

End With

Dim calculator As New Calculator(Of Decimal, Decimal)(classname, ss)

Return calculator

End Function

是否错过了一些装配？

干杯！

Answer 1

我终于找到了解决问题的方法。我最近发现，默认情况下，encodeom使用的是2.0编译器，而不是最新的编译器（.net 3.5的vb编译器）。您必须在创建VB编译器的实例时通过字典（字符串，sting）明确指定您将使用3.5 VB编译器...

难以使用VB Code Dom（在生成的代码中使用If表达式）

1 个答案: