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Populate a Dropdown using VB.NET and Code-behind
This simple example demonstrates how to populate a dropdown box using a code-behind
page. This is one method of separating presentation from business logic.
| ASPX page <%@ Page Language="VB"
debug="true" Inherits="myCodeBehind" src="2.vb"%>
<html>
<title>Fill dropdown with VB, Sql DataReader & Code Behind</title>
</head>
<body>
<asp:Dropdownlist id="atMyDropDownList" DataValueField =
"au_lname" DataTextField = "au_id" runat="server" />
</body>
</html> |
| Code behind form Imports System
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.HtmlControls
Imports System.Data
Imports System.Data.SqlClient
Imports System.Configuration
public class myCodeBehind : Inherits System.Web.UI.Page
public atMyDropDownList as DropDownList
private Sub Page_Load(Sender as object, e as System.EventArgs)
dim sqlText as string = "select * from
authors"
atMyDropDownList.DataSource = GetDr( sqlText )
atMyDropDownList.DataBind()
End Sub
private Function GetDr(sqlText as string) as SqlDataReader
dim dr as SqlDataReader
dim sqlConn as SqlConnection = new
SqlConnection(ConnectionString())
dim sqlCmd as SqlCommand = new
SqlCommand(sqlText,sqlConn)
sqlCmd.Connection.Open()
dr =
sqlCmd.ExecuteReader(System.Data.CommandBehavior.CloseConnection)
return dr
End Function
private Function ConnectionString() as string
dim myConn as string =
ConfigurationSettings.AppSettings("DSN_pubs")
return myConn
End Function
private Sub Page_Init(Sender as object, e as System.EventArgs)
End Sub
End Class |
| Web.Config <configuration>
<appSettings>
<add key="DSN_NorthWind"
value="server=(local)\NetSDK;database=NorthWind;Trusted_Connection=yes" />
<add key="DSN_pubs"
value="server=(local)\NetSDK;database=pubs;Trusted_Connection=yes" />
</appSettings>
</configuration> |
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