请大家看一下这个东东,简单的DOS模拟器,有一问题请 VB大人指教啦

[sonoffreedom]

请大家看一下这个东东,简单的DOS模拟器,
Imports System.io

Module Module1
Public input As String
Class dos_functions
Dim command_value As String
Public Sub dos_emu_start()
Console.WriteLine(" The DOS Emulator. Made BY YJ,需要帮助请输入 help")
Console.WriteLine(" <C> 版权所有 1986-2008 YangJuSoft Corp.")

End Sub
Public Sub wait_input()
Console.Write("C:\")
input = Console.ReadLine
End Sub

Public Sub dir()
Console.WriteLine("目前驱动器")
End Sub
End Class
Function help() As String
Console.WriteLine("目前可用命令如下:")
Console.WriteLine("help:帮助")
Console.WriteLine("exit:退出")
Console.WriteLine("Dir:显示目录")
Console.WriteLine("********** Made by YJ **********")
End Function
Function dir() As String
Dim filepath As String = input
Dim filedir As New DirectoryInfo("c:\")
Console.WriteLine("{0}目录:", filedir.FullName)
Dim subdir() As DirectoryInfo = filedir.GetDirectories
For Each r As DirectoryInfo In subdir
Console.WriteLine("{0} {1} {2}", r.FullName,vbtab, r.CreationTime)
Next


End Function
Function scan_command() As String

Select Case UCase(input)
Case Is = "HELP"
help()
Case Is = "DIR"
dir()

End Select
End Function

Sub Main()

Dim newdos As New dos_functions
newdos.dos_emu_start()


While UCase(input) <> "EXIT"

scan_command()
newdos.wait_input()
End While

End Sub

End Module


这是一个简单的dos 模拟器，用VB.NET来实现，我想问:

这个DOS模拟器是用functions 来调用一个个独立函数的，用"CASE is" 来检测是调用 help 或 dir 或exit ，请问有没有更好的方法来检测调用什么命令呢(VB2005)

比如用 类的什么东东还是？


我觉得,用一个函数写来检测 input(就是我在命令行输入的string值) 等于哪个独立函数，再执行,这样应该比较好吧

不过目前我不知道应该如何这样做，这样再多写一个功能函数的时候，就不必在CASE IS 后面多加CASE IS ...的选择语句了,请大家指教啦

[ZengHD]

可以是可以，使用反射+工厂，但代码比你现在的复杂很多

[ZengHD]

Imports System.IO
Imports System.Reflection

Namespace WindowsApplication1

    Module Module1
        Public input As String

        Class dos_functions
            Dim command_value As String
            Public Sub dos_emu_start()
                Console.WriteLine(" The DOS Emulator. Made BY YJ,需要帮助请输入 help")
                Console.WriteLine(" <C> 版权所有 1986-2008 YangJuSoft Corp.")

            End Sub
            Public Sub wait_input()
                Console.Write("C:\")
                input = Console.ReadLine
            End Sub

            Public Sub dir()
                Console.WriteLine("目前驱动器")
            End Sub
        End Class

        Public Class Command

            Function help() As String
                Console.WriteLine("目前可用命令如下:")
                Console.WriteLine("help:帮助")
                Console.WriteLine("exit:退出")
                Console.WriteLine("Dir:显示目录")
                Console.WriteLine("********** Made by YJ **********")
                Return ""
            End Function

            Function dir() As String
                Dim filepath As String = input
                Dim filedir As New DirectoryInfo("c:\")
                Console.WriteLine("{0}目录:", filedir.FullName)
                Dim subdir() As DirectoryInfo = filedir.GetDirectories
                For Each r As DirectoryInfo In subdir
                    Console.WriteLine("{0}    {1}    {2}", r.FullName, vbTab, r.CreationTime)
                Next
                Return ""

            End Function

            Function scan_command() As String
                If input Is Nothing Or input = "" Then Return ""

                Dim obj As Object = Activator.CreateInstance(MyClass.GetType)
                If obj Is Nothing Then Return ""

                Dim MyMethod As MethodInfo = obj.GetType().GetMethod(input)
                If Not MyMethod Is Nothing Then
                    MyMethod.Invoke(obj, Nothing)
                End If

                Return ""
            End Function

        End Class

        Sub Main()

            Dim newdos As New dos_functions
            newdos.dos_emu_start()

            Dim comm As New Command
            While UCase(input) <> "EXIT"
                comm.scan_command()
                newdos.wait_input()
            End While

        End Sub

    End Module

End Namespace

[sonoffreedom]

很感谢噢!!!!!!!!!
不过,
Function scan_command() As String
If input Is Nothing Or input = "" Then Return ""

Dim obj As Object = Activator.CreateInstance(MyClass.GetType)
If obj Is Nothing Then Return ""

Dim MyMethod As MethodInfo = obj.GetType().GetMethod(input)
If Not MyMethod Is Nothing Then
MyMethod.Invoke(obj, Nothing)
End If

这几行能解释一下么??

[ZengHD]

你去查查和反射相关的资料吧