用CodeDom、Reflection做一个简易计算器

将代码粘贴到一个VB文件即可运行。我这里只是给出一种思路，按这种思路，可以做出一个强劲的计算器，也可以做出一个代码测试器或者是练习器。

Option Strict Off

Imports System.IO

Imports System.CodeDom.Compiler

Imports System.Reflection

Namespace LzmTW.Test

Public Class frmCal

Inherits System.Windows.Forms.Form

Private Code As New CodeBuilder

Private myMode As Mode

#Region " Windows 窗体设计器生成的代码 "

Public Sub New()

MyBase.New()

'该调用是 Windows 窗体设计器所必需的。

InitializeComponent()

'在 InitializeComponent() 调用之后添加任何初始化

End Sub

'窗体重写 dispose 以清理组件列表。

Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)

If disposing Then

If Not (components Is Nothing) Then

components.Dispose()

End If

MyBase.Dispose(disposing)

End Sub

'Windows 窗体设计器所必需的

Private components As System.ComponentModel.IContainer

'注意: 以下过程是 Windows 窗体设计器所必需的

'可以使用 Windows 窗体设计器修改此过程。

'不要使用代码编辑器修改它。

Friend WithEvents tbCode As System.Windows.Forms.TextBox

Friend WithEvents tbResult As System.Windows.Forms.TextBox

Friend WithEvents btnCal As System.Windows.Forms.Button

Friend WithEvents tbReturnPara As System.Windows.Forms.TextBox

Friend WithEvents Label1 As System.Windows.Forms.Label

Friend WithEvents Label2 As System.Windows.Forms.Label

Friend WithEvents tbSub As System.Windows.Forms.TextBox

Friend WithEvents Label3 As System.Windows.Forms.Label

Friend WithEvents Label4 As System.Windows.Forms.Label

Friend WithEvents Button1 As System.Windows.Forms.Button

Private Sub InitializeComponent()

Me.tbCode = New System.Windows.Forms.TextBox

Me.tbResult = New System.Windows.Forms.TextBox

Me.btnCal = New System.Windows.Forms.Button

Me.tbReturnPara = New System.Windows.Forms.TextBox

Me.Label1 = New System.Windows.Forms.Label

Me.Label2 = New System.Windows.Forms.Label

Me.tbSub = New System.Windows.Forms.TextBox

Me.Label3 = New System.Windows.Forms.Label

Me.Label4 = New System.Windows.Forms.Label

Me.Button1 = New System.Windows.Forms.Button

Me.SuspendLayout()

'tbCode

Me.tbCode.Anchor = CType((((System.Windows.Forms.AnchorStyles.Top Or System.Windows.Forms.AnchorStyles.Bottom) _

Or System.Windows.Forms.AnchorStyles.Left) _

Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)

Me.tbCode.Location = New System.Drawing.Point(8, 32)

Me.tbCode.Multiline = True

Me.tbCode.Name = "tbCode"

Me.tbCode.ScrollBars = System.Windows.Forms.ScrollBars.Both

Me.tbCode.Size = New System.Drawing.Size(584, 72)

Me.tbCode.TabIndex = 0

Me.tbCode.Text = "'给定半径，求周长和面积" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "Dim M(3)" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "M(0)=20" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "M(1)=M(0)*Math.PI*2" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "M(2)=Math.PI*Math.Pow(M(0),2)" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "D" & _

"im Result" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "Result=""半径:"" + M(0).Tostring +vbcrlf+""周长:"" + M(1).ToString+vbcrlf +""面" & _

"积:"" +M(2).Tostring" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " " & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " " & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "'打开Excel" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "Dim oExcel As ExcelObj" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "oExcel" & _

".Open" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "oExcel.GetData(Result)"

'tbResult

Me.tbResult.Anchor = CType(((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left) _

Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)

Me.tbResult.Location = New System.Drawing.Point(8, 360)

Me.tbResult.Multiline = True

Me.tbResult.Name = "tbResult"

Me.tbResult.ScrollBars = System.Windows.Forms.ScrollBars.Both

Me.tbResult.Size = New System.Drawing.Size(584, 64)

Me.tbResult.TabIndex = 1

Me.tbResult.Text = ""

'btnCal

Me.btnCal.Anchor = CType((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)

Me.btnCal.Location = New System.Drawing.Point(448, 320)

Me.btnCal.Name = "btnCal"

Me.btnCal.Size = New System.Drawing.Size(120, 32)

Me.btnCal.TabIndex = 2

Me.btnCal.Text = "计算(&C)"

'tbReturnPara

Me.tbReturnPara.Anchor = CType((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left), System.Windows.Forms.AnchorStyles)

Me.tbReturnPara.Location = New System.Drawing.Point(104, 112)

Me.tbReturnPara.Name = "tbReturnPara"

Me.tbReturnPara.Size = New System.Drawing.Size(152, 21)

Me.tbReturnPara.TabIndex = 3

Me.tbReturnPara.Text = "Result"

'Label1

Me.Label1.Anchor = CType((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left), System.Windows.Forms.AnchorStyles)

Me.Label1.Location = New System.Drawing.Point(8, 112)

Me.Label1.Name = "Label1"

Me.Label1.Size = New System.Drawing.Size(72, 16)

Me.Label1.TabIndex = 4

Me.Label1.Text = "返回值参数"

'Label2

Me.Label2.Location = New System.Drawing.Point(8, 8)

Me.Label2.Name = "Label2"

Me.Label2.Size = New System.Drawing.Size(128, 16)

Me.Label2.TabIndex = 5

Me.Label2.Text = "主程序："

'tbSub

Me.tbSub.Anchor = CType(((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left) _

Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)

Me.tbSub.Location = New System.Drawing.Point(8, 176)

Me.tbSub.Multiline = True

Me.tbSub.Name = "tbSub"

Me.tbSub.ScrollBars = System.Windows.Forms.ScrollBars.Both

Me.tbSub.Size = New System.Drawing.Size(584, 136)

Me.tbSub.TabIndex = 6

Me.tbSub.Text = "Class ExcelObj" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " Private shared obj,Wb,Ws" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " Public Shared Sub Open" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " ob" & _

"j=CreateObject(""Excel.Application"")" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " obj.Visible = True" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " End Sub" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " P" & _

"ublic Shared Sub GetData(Value)" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " If Wb Is Nothing Then" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " Wb=obj." & _

"WorkBooks.Add " & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " Ws=Wb.WorkSheets.Add" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " End If" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " Ws.Cells(1" & _

",1)=Value" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & " End Sub" & Microsoft.VisualBasic.ChrW(13) & Microsoft.VisualBasic.ChrW(10) & "End Class"

'Label3

Me.Label3.Anchor = CType((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left), System.Windows.Forms.AnchorStyles)

Me.Label3.Location = New System.Drawing.Point(8, 152)

Me.Label3.Name = "Label3"

Me.Label3.Size = New System.Drawing.Size(128, 16)

Me.Label3.TabIndex = 7

Me.Label3.Text = "函数："

'Label4

Me.Label4.Anchor = CType((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left), System.Windows.Forms.AnchorStyles)

Me.Label4.Location = New System.Drawing.Point(8, 336)

Me.Label4.Name = "Label4"

Me.Label4.Size = New System.Drawing.Size(128, 16)

Me.Label4.TabIndex = 8

Me.Label4.Text = "结果："

'Button1

Me.Button1.Anchor = CType((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Right), System.Windows.Forms.AnchorStyles)

Me.Button1.Location = New System.Drawing.Point(240, 320)

Me.Button1.Name = "Button1"

Me.Button1.Size = New System.Drawing.Size(120, 32)

Me.Button1.TabIndex = 9

Me.Button1.Text = "查看代码"

'frmCal

Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)

Me.ClientSize = New System.Drawing.Size(600, 429)

Me.Controls.Add(Me.Button1)

Me.Controls.Add(Me.Label4)

Me.Controls.Add(Me.Label3)

Me.Controls.Add(Me.tbSub)

Me.Controls.Add(Me.Label2)

Me.Controls.Add(Me.Label1)

Me.Controls.Add(Me.tbReturnPara)

Me.Controls.Add(Me.btnCal)

Me.Controls.Add(Me.tbResult)

Me.Controls.Add(Me.tbCode)

Me.Name = "frmCal"

Me.Text = "简易代码计算器"

Me.ResumeLayout(False)

End Sub

#End Region

Private Sub btnCal_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCal.Click

Code.Clear()

Dim i As Int16

For i = 0 To tbCode.Lines.Length - 1

Code.AppendCode(2, tbCode.Lines(i))

Code.AppendCode(2, "Return " & Me.tbReturnPara.Text)

Code.AppendCode(1, "End Function")

Code.AppendCode()

For i = 0 To tbSub.Lines.Length - 1

Code.AppendCode(2, tbSub.Lines(i))

myMode = New Mode

myMode.GetMode(Code.ToString)

' MsgBox(myMode.CodeString)

Me.tbResult.Text = ""

Me.tbResult.Text = myMode.CalResult

End Sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

If Not myMode Is Nothing Then

Me.tbResult.Text = ""

Me.tbResult.Text = myMode.CodeString

End If

End Sub

End Class

Public Class Mode

Private Comp As ICodeCompiler = New VBCodeProvider().CreateCompiler

Private cp As CompilerParameters = New CompilerParameters

Private _Compiled As Object = Nothing

Private mi As MethodInfo

Private MyCode As CodeBuilder

Public ReadOnly Property CodeString() As String

Get

Return MyCode.ToString

End Get

End Property 'CodeString

Sub New()

End Sub

Sub GetMode(ByVal ModeString As String)

MyCode = New CodeBuilder

With MyCode

.AppendCode("Imports System")

.AppendCode("Imports System.Data")

.AppendCode("Imports System.Math")

.AppendCode("Imports Microsoft.VisualBasic")

.AppendCode()

.AppendCode("Public Class DealMode")

.AppendCode(" Public Function GetM()")

.AppendCode(ModeString)

' .AppendCode(" End Function")

.AppendCode("End Class")

End With

End Sub 'GetMode

Public Function CalResult() As Object

cp.ReferencedAssemblies.Add("System.dll")

cp.ReferencedAssemblies.Add("System.Data.dll")

cp.ReferencedAssemblies.Add("System.Xml.dll")

cp.ReferencedAssemblies.Add("Microsoft.VisualBasic.dll")

cp.GenerateExecutable = False

cp.GenerateInMemory = True

'dim CodeBuilding as

Dim code As String

code = MyCode.ToString

Dim cr As CompilerResults = Comp.CompileAssemblyFromSource(cp, code)

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

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("DealMode")

mi = _Compiled.GetType().GetMethod("GetM")

Return mi.Invoke(_Compiled, Nothing)

End Function

End Class 'Mode

Public Class CodeBuilder

Private _StringBuilder As System.Text.StringBuilder

Private Const CodeFormat As String = "{0}{1}" & ControlChars.CrLf

Sub New()

_StringBuilder = New System.Text.StringBuilder

End Sub

Public Overloads Sub AppendCode()

_StringBuilder.AppendFormat(CodeFormat, Space(0), Space(0))

End Sub

Public Overloads Sub AppendCode(ByVal CodeString As String)

_StringBuilder.AppendFormat(CodeFormat, Space(0), CodeString)

End Sub

Public Overloads Sub AppendCode(ByVal CodeFloor As Integer, ByVal CodeString As String)

_StringBuilder.AppendFormat(CodeFormat, Space(CodeFloor * 4), CodeString)

End Sub

Public Sub AppendFromFile(ByVal FileName As String)

If Not System.IO.File.Exists(FileName) Then

MsgBox(FileName & "不存在.")

Exit Sub

End If

Dim tmpStr As String

Dim fs As System.IO.FileStream

fs = New System.IO.FileStream(FileName, IO.FileMode.Open, IO.FileAccess.Read, IO.FileShare.Read)

Dim Reader As New System.IO.StreamReader(fs, System.Text.Encoding.Default)

tmpStr = Reader.ReadToEnd

Reader.Close()

fs.Close()

_StringBuilder.Append(tmpStr)

End Sub

Public Overrides Function ToString() As String

Return _StringBuilder.ToString

End Function

Public Sub Clear()

If _StringBuilder.Length > 0 Then _StringBuilder.Remove(0, _StringBuilder.Length - 1)

End Sub

End Class 'CodeBuilder

End Namespace