如何把含c＃代码的字符串变成代码指令？

[apengcn]

如举个简单的例子，当然字符串的内容没那么简单
int i;
string code="i=10000";
//这里如何加一句转换语句把code的内容变成实际能编译的语句，使10000真的赋值给变量i
int j=i/10;

[redant0]

http://www.cnblogs.com/lovecherry/archive/2005/03/25/125520.html

[apengcn]

谢谢各位，可是这些方法还是有点问题，象我上面例子中的变量i无法传递到表达式中去啊

[syeerzy]

使用反射,不过真的完全实现起来够自己去写个编译器了

[jialiang]

如果能写完整差不多就可以去写编译器了

[真相重于对错]

使用反射

[apengcn]

具体如何写反射，请给个例子好吗

[LoveCherry]

http://www.cnblogs.com/lovecherry/archive/2005/03/25/125520.html

[SeeSunSet]

Private Function GetJedgement(ByVal Expression As String) As Boolean
Dim Comp As ICodeCompiler = New VBCodeProvider().CreateCompiler
Dim cp As CompilerParameters = New CompilerParameters
Dim _Compiled As Object = Nothing

cp.ReferencedAssemblies.Add("system.dll")
cp.ReferencedAssemblies.Add("system.data.dll")
cp.ReferencedAssemblies.Add("system.xml.dll")
cp.GenerateExecutable = False
cp.GenerateInMemory = True
'dim CodeBuilding as
Dim code As String
code = "Imports System " & vbCrLf & _
"Imports System.Data " & vbCrLf & _
"Imports System.Xml " & vbCrLf & _
"Public Class Judgement " & vbCrLf & _
" Public Function GetJude() as Object " & vbCrLf & _
" Return (" & Expression & ") " & vbCrLf & _
" End Function " & vbCrLf & _
"End Class "

Dim cr As CompilerResults = Comp.CompileAssemblyFromSource(cp, code.ToString())
Debug.Write(code.ToString)
If (cr.Errors.HasErrors) Then

Dim ErrorMessage As String

ErrorMessage = "编译错误:" & vbCrLf
Dim Err As CompilerError
For Each Err In cr.Errors
ErrorMessage = ErrorMessage & Err.ErrorText & vbCrLf
Next
Debug.WriteLine(ErrorMessage)
#If DEBUG Then
Stop
#Else
Throw New Exception("编译错误: " + ErrorMessage)
#End If
End If

Dim a As System.Reflection.Assembly = cr.CompiledAssembly
_Compiled = a.CreateInstance("Judgement")

Dim mi As MethodInfo = _Compiled.GetType().GetMethod("GetJude")
Return (CType(mi.Invoke(_Compiled, Nothing), Boolean))
End Function
'测试
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim x As String = "6"
Dim tmp As String = x & ">5 And " & x & "<10"
MsgBox(GetJedgement(InputBox("输入表达式:", , tmp)))
End Sub

[兔子-顾问]

学习学习。