admin_book_update.aspx.vb

《ASP.NET C#程序设计案例教程》

Imports System.Web.UI.HtmlControls          '因为用到了文件上传控件
Imports System.IO              '因为用到了Stream对象


Public Class admin_book_update
    Inherits System.Web.UI.Page

#Region " Web 窗体设计器生成的代码 "

    '该调用是 Web 窗体设计器所必需的。
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

    End Sub
    Protected WithEvents txtBookName As System.Web.UI.WebControls.TextBox
    Protected WithEvents require1 As System.Web.UI.WebControls.RequiredFieldValidator
    Protected WithEvents txtBookAuthor As System.Web.UI.WebControls.TextBox
    Protected WithEvents require2 As System.Web.UI.WebControls.RequiredFieldValidator
    Protected WithEvents txtBookPrice As System.Web.UI.WebControls.TextBox
    Protected WithEvents require3 As System.Web.UI.WebControls.RequiredFieldValidator
    Protected WithEvents txtBookNum As System.Web.UI.WebControls.TextBox
    Protected WithEvents require4 As System.Web.UI.WebControls.RequiredFieldValidator
    Protected WithEvents dropKindId As System.Web.UI.WebControls.DropDownList
    Protected WithEvents txtBookIntro As System.Web.UI.WebControls.TextBox
    Protected WithEvents require5 As System.Web.UI.WebControls.RequiredFieldValidator
    Protected WithEvents txtBookIndex As System.Web.UI.WebControls.TextBox
    Protected WithEvents imgPicture As System.Web.UI.WebControls.Image
    Protected WithEvents txtBookId As System.Web.UI.WebControls.TextBox
    Protected WithEvents btnEnter As System.Web.UI.WebControls.Button
    Protected WithEvents lblMessage As System.Web.UI.WebControls.Label
    Protected WithEvents UploadFile As System.Web.UI.HtmlControls.HtmlInputFile

    '注意: 以下占位符声明是 Web 窗体设计器所必需的。
    '不要删除或移动它。
    Private designerPlaceholderDeclaration As System.Object

    Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: 此方法调用是 Web 窗体设计器所必需的
        '不要使用代码编辑器修改它。
        InitializeComponent()
    End Sub

#End Region

    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        '在此处放置初始化页的用户代码
        If Not Page.IsPostBack Then
            Call myDataBind()
        End If
    End Sub

    '该过程用于绑定类别
    Sub myDataBind()
        '下面首先获取本书的有关信息
        Dim dbk As New DataBook(Request.QueryString("BookId"))
        txtBookName.Text = dbk.BookName
        txtBookAuthor.Text = dbk.BookAuthor
        txtBookPrice.Text = dbk.BookPrice
        txtBookNum.Text = dbk.BookNum
        txtBookIntro.Text = dbk.BookIntro
        txtBookIndex.Text = dbk.BookIndex
        txtBookId.Text = dbk.BookId      '将BookId保存到隐藏文本框中

        imgPicture.ImageUrl = "../showimage.aspx?BookId=" & dbk.BookId

        '下面建立DataBusiness对象，返回所有文章
        Dim dbs As New DataBusiness
        Dim dv As DataView = dbs.GetKind()
        '下面绑定数据
        dropKindId.DataSource = dv
        dropKindId.DataTextField = "KindName"
        dropKindId.DataValueField = "KindId"
        dropKindId.SelectedValue = dbk.KindId    '设置预选项
        dropKindId.DataBind()
    End Sub

    Private Sub btnEnter_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnEnter.Click
        '判断一下，如果不是管理员，就返回到首页
        If DataUserLog.IsAdmin() = False Then
            Response.Write("<script language='javascript'>top.document.location='../index.aspx';</script>")
        End If

        '下面首先获取书名等普通数据
        Dim strBookName, strBookAuthor, strBookIntro, strBookIndex As String
        Dim sglBookPrice As Single
        Dim intBookNum, intKindId, intBookId As Integer
        strBookName = txtBookName.Text
        strBookAuthor = txtBookAuthor.Text
        strBookIntro = txtBookIntro.Text
        strBookIndex = txtBookIndex.Text
        sglBookPrice = txtBookPrice.Text
        intBookNum = txtBookNum.Text
        intKindId = dropKindId.SelectedItem.Value
        intBookId = txtBookId.Text

        '下面获取上传的图片数据,并利用Stream对象将其保存到二进制数组中
        Dim FileSize As Long = UploadFile.PostedFile.ContentLength
        Dim bytPicture(FileSize) As Byte     '建立一个和文件大小一致的二进制数组					
        Dim objStream As Stream              '定义一个Stream对象变量
        objStream = UploadFile.PostedFile.InputStream       '读取上传文件到Stream对象中
        objStream.Read(bytPicture, 0, FileSize)        '读取整个文件到buffer数租中

        '下面调用方法添加记录
        Dim dbs As New DataBusiness
        If dbs.UpdateBook(intBookId, strBookName, strBookAuthor, sglBookPrice, intBookNum, bytPicture, strBookIntro, strBookIndex, intKindId) = True Then
            '更新成功，返回列表页面
            Response.Redirect("admin_book_list.aspx")
        Else
            lblMessage.Text = "发生错误，没有更新"
        End If
    End Sub
End Class