我是 ASP.net 和 VB.net 的新手。所以我从 VB 2008 中的 ASP.Net 3.5 开始学习这本书
select.aspx.vb 上的代码是
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Configuration
Partial Public Class _Select
Inherits System.Web.UI.Page
Private Conn As String = WebConfigurationManager.ConnectionStrings("MyConnectionString").ConnectionString
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
FillAuthorList()
End If
End Sub
Private Sub FillAuthorList()
lstAuthor.Items.Clear()
' Define the Select statement.
' Three pieces of information are needed: the unique id
' and the first and last name.
Dim selectSQL As String = "SELECT Nama_Depan, Nama_Belakang, ID FROM Employee"
' Define the ADO.NET objects.
Dim con As New SqlConnection(Conn)
Dim cmd As New SqlCommand(selectSQL, con)
Dim reader As SqlDataReader
' Try to open database and read information.
Try
con.Open()
reader = cmd.ExecuteReader()
' For each item, add the author name to the displayed
' list box text, and store the unique ID in the Value property.
Do While reader.Read()
Dim newItem As New ListItem()
newItem.Text = reader("Nama_Depan") & ", " & reader("Nama_Belakang")
newItem.Value = reader("ID").ToString()
lstAuthor.Items.Add(newItem)
Loop
reader.Close()
Catch err As Exception
lblResults.Text = "Error reading list of names."
lblResults.Text &= err.Message
Finally
con.Close()
End Try
End Sub
Protected Sub lstAuthor_SelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs) Handles lstAuthor.SelectedIndexChanged
' Create a Select statement that searches for a record
' matching the specific author ID from the Value property.
Dim selectSQL As String
selectSQL = "SELECT * FROM Employee "
selectSQL &= "WHERE ID='" & lstAuthor.SelectedItem.Value & "' "
' Define the ADO.NET objects.
Dim con As New SqlConnection(Conn)
Dim cmd As New SqlCommand(selectSQL, con)
Dim reader As SqlDataReader
' Try to open database and read information.
Try
con.Open()
reader = cmd.ExecuteReader()
reader.Read()
' Build a string with the record information,
' and display that in a label.
Dim sb As New StringBuilder()
sb.Append("<b>")
sb.Append(reader("Nama_Depan"))
sb.Append(", ")
sb.Append(reader("Nama_Belakang"))
sb.Append("</b><br />")
lblResults.Text = sb.ToString()
reader.Close()
Catch err As Exception
lblResults.Text = "Error getting author. "
lblResults.Text &= err.Message
Finally
con.Close()
End Try
End Sub
End Class
而 select.aspx 是
<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Select.aspx.vb" Inherits="connn._Select" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ListBox ID="lstAuthor" runat="server" ></asp:ListBox>
<br />
<asp:Label ID="lblResults" runat="server">
</asp:Label>
</div>
</form>
</body>
</html>
我正在尝试选择 ID="lstAuthor" 的列表框时，标签框将传递该值但未能显示。