做一个智能的聊天机器人并不容易，我这里只是实现了一个很简易的聊天机器人。

   当你和这个机器人聊天的时候，每次机器人会根据你说的话的关键词找到回答的语句。如果找不到就随机的说一句默认语言。数据存储格式是xml。

   以下是xml的原文件：

<?xml version="1.0" encoding="UTF-8"?>
<chat>
  <!--默认的聊天语句-->
  <default>
    <content>你在哪里？</content>
    <content>你还是学生吗？</content>

   .........

 </default>
 <!--回答指定关键词的语句序列-->

<answer>

    <content key="怪"> 不怪</content>
    <content key="慢">是啊，慢</content>
    <content key="喂">什么事？</content>
    <content key="88">再见</content>
    <content key="谢">没什么好谢的</content>
    <content key="滚">我不会滚，我会走</content>

......

<answer>
</chat>

////////////////////////////////////////////////////////////////////

以下是主要的源代码：

Imports System.Xml
Public Class Form1
    Inherits System.Windows.Forms.Form

#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
        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 RichTextBox1 As System.Windows.Forms.RichTextBox
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Dim resources As System.Resources.ResourceManager = New System.Resources.ResourceManager(GetType(Form1))
        Me.RichTextBox1 = New System.Windows.Forms.RichTextBox
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.SuspendLayout()
        '
        'RichTextBox1
        '
        Me.RichTextBox1.Location = New System.Drawing.Point(0, 0)
        Me.RichTextBox1.Name = "RichTextBox1"
        Me.RichTextBox1.ReadOnly = True
        Me.RichTextBox1.Size = New System.Drawing.Size(560, 304)
        Me.RichTextBox1.TabIndex = 2
        Me.RichTextBox1.Text = ""
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(0, 312)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(456, 21)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = ""
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(472, 312)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(72, 24)
        Me.Button1.TabIndex = 1
        Me.Button1.Text = "Enter"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(560, 341)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.TextBox1)
        Me.Controls.Add(Me.RichTextBox1)
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle
        Me.Icon = CType(resources.GetObject("$this.Icon"), System.Drawing.Icon)
        Me.MaximizeBox = False
        Me.Name = "Form1"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "青蛙王子"
        Me.ResumeLayout(False)

    End Sub

#End Region

    

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        readxml()
    End Sub

    Dim xmlFile As String = "./robot.xml"
    Dim chatList As New ArrayList
    Dim answerList As New Hashtable
    Dim random As New System.Random

    Private Sub readxml()
        Try
            Dim doc As XmlDocument = New XmlDocument
            doc.Load(xmlFile)
            Dim nodeList As XmlNodeList
            Dim root As XmlElement = doc.DocumentElement
            '--默认的聊天语句--
            nodeList = root.SelectNodes("/chat/default/content")
            Dim node As XmlNode
            For Each node In nodeList
                chatList.Add(node.InnerText)
            Next
            '回答指定关键词的语句序列--
            nodeList = root.SelectNodes("/chat/answer/content")
            For Each node In nodeList
                answerList.Add(node.Attributes("key").Value, node.InnerText)
            Next
        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'RichTextBox1.SelectionBullet = True
        Dim Content$ = TextBox1.Text.Trim
        If (Content = "") Then
            RichTextBox1.AppendText("请不要欺骗我的感情,谢谢!" + ControlChars.Lf)
            Exit Sub
        End If
        If (Content.IndexOf(":") <> -1) Then
            If learnNewWord(Content) Then
                RichTextBox1.AppendText("我又学会了新的东西,谢谢!" + ControlChars.Lf)
            End If
            Exit Sub
        End If
        RichTextBox1.AppendText(Content + ControlChars.Lf)
        Dim aStr$ = getSimilarContent(Content)
        If (aStr = Nothing) Then
            Dim i% = random.Next(1, chatList.Count)
            aStr = chatList.Item(i)
        End If
        RichTextBox1.AppendText(aStr.Trim + ControlChars.Lf)
        RichTextBox1.Refresh()
    End Sub
    '得到相似的字符串
    Function getSimilarContent(ByVal content As String) As String
        Dim keys As System.Collections.ICollection = answerList.Keys
        Dim enumR As System.Collections.IEnumerator = keys.GetEnumerator
        While (enumR.MoveNext)
            Dim str$ = enumR.Current
            If content.Equals(str) Then
                Return answerList(str)
            End If
        End While
        enumR.Reset()
        While (enumR.MoveNext)
            Dim str$ = enumR.Current
            If (content.IndexOf(str) <> -1) Or (str.IndexOf(content) <> -1) Then
                Return answerList(str)
            End If
        End While
        Return Nothing
    End Function

    '添加新的语句
    Function learnNewWord(ByVal content As String) As Boolean
        Try
            Dim doc As XmlDocument = New XmlDocument
            Dim i% = content.IndexOf(":")
            Dim str1$ = content.Substring(0, i)
            Dim str2$ = content.Substring(i + 1)
            doc.Load(xmlFile)
            Dim elem As XmlElement = doc.CreateElement("content")
            Dim attr As XmlAttribute = doc.CreateAttribute("key")
            attr.Value = str1
            elem.InnerText = str2
            elem.Attributes.Append(attr)
            '添加新的语句--
            Dim root As XmlElement = doc.DocumentElement
            Dim xmlNode As XmlNode = root.SelectSingleNode("/chat/answer")
            xmlNode.AppendChild(elem)
            answerList.Add(str1, str2)
            doc.Save(xmlFile)
            Return True
        Catch ex As Exception
            MsgBox(ex.Message)
            Return False
        End Try
    End Function

    Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If e.KeyChar.Equals(ControlChars.Cr) Then
            Button1_Click(Nothing, Nothing)
        End If
    End Sub
End Class