二手书直卖 代码分享

二手书直卖 是用VB.Net开发的一个Windows桌面应用程序，里面用到的知识点有：

• ListView控件的用法
• WebRequest和WebResponse实现网抓
• XML的节点定位、XPath用法
• 使用System.Net.Mail给买家发邮件

源代码如下：

Imports System.Xml
Imports System.Net
Imports System.IO
Public Class Form1
    Private Const ns As String = "https://files.cnblogs.com/files/ryueifu-VBA/"
    Private FM2 As Form2
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles Me.Load
        Dim Doc As XmlDocument
        Dim request As WebRequest
        Dim response As WebResponse
        Dim S As Stream
        Dim book As XmlNode
        Dim books As XmlNodeList
        Dim attr As XmlAttribute
        Dim Item As ListViewItem
        With Me.ListView1
            .View = View.Details
            .Columns.Add(text:="书号", =100)
            .Columns.Add(text:="书名", =200)
            .Columns.Add(text:="作者", =100)
            .Columns.Add(text:="定价", =50)
            .Columns.Add(text:="售价", =50)
            .Columns.Add(text:="新旧", =50)
            .FullRowSelect = True
            .MultiSelect = False
        End With
        With Me.PictureBox1
            .SizeMode = PictureBoxSizeMode.StretchImage
        End With
        request = WebRequest.Create(requestUriString:=ns & "Book.xml")
        response = request.GetResponse()
        S = response.GetResponseStream
        Doc = New XmlDocument
        Doc.Load(inStream:=S)
        books = Doc.SelectNodes(xpath:="Root/book")
        Item = Nothing
        For Each book In books
            For Each attr In book.Attributes
                If attr.Name = "ISBN" Then
                    Item = Me.ListView1.Items.Add(text:=attr.Value)
                Else
                    Item.SubItems.Add(text:=attr.Value)
                End If
            Next
        Next
    End Sub

    Private Sub ListView1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ListView1.SelectedIndexChanged
        Dim request As WebRequest
        Dim response As WebResponse
        Dim S As Stream
        With Me.ListView1
            If .SelectedItems.Count = 1 Then
                request = WebRequest.Create(requestUriString:=ns & .SelectedItems.Item(0).Text & ".bmp")
                response = request.GetResponse()
                S = response.GetResponseStream
                Me.PictureBox1.Image = Image.FromStream(S)
            End If
        End With
    End Sub

    Private Sub 购买此书ToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles 购买此书ToolStripMenuItem.Click
        If FM2 Is Nothing Then
            FM2 = New Form2()
        End If
        With Me.ListView1
            If .SelectedItems.Count = 1 Then
                ISBN = .SelectedItems.Item(0).Text
                BookName = .SelectedItems.Item(0).SubItems(1).Text
                FM2.Text = ISBN & " - 订单"
                FM2.ShowDialog()
            End If
        End With
    End Sub
End Class

仔细看完代码的，奖励美女一枚：