HtmlSelect.DataTextField Property

 

Gets or sets the field from the data source to bind to the ListItem.Text property of each item in the HtmlSelect control.

Namespace:   System.Web.UI.HtmlControls
Assembly:  System.Web (in System.Web.dll)

Public Overridable Property DataTextField As String

Property Value

Type: System.String

The field from the data source to bind to the ListItem.Text property of each item in the HtmlSelect control. The default value is an empty string (""), which indicates that the property has not been set.

Use the DataTextField property to specify which field from the data source to bind to the ListItem.Text property of each item in the control. This property is commonly used to provide a value for the ListItem.Text property that differs from the value of the ListItem.Value property.

The HtmlSelect class provides two properties for specifying the data source to bind to. The DataSource property allows you to bind an HtmlSelect control to any collection that implements the System.Collections.IEnumerable or System.ComponentModel.IListSource interfaces (such as System.Data.DataView, System.Collections.ArrayList, or System.Collections.Generic.List(Of T)). When you use the DataSource property to specify the data source, you must explicitly call the DataBind method to bind the control and its DataTextField property to the data source.

The DataSourceID property allows you to bind an HtmlSelect control to a data source control that represents a data source. When you use the DataSourceID property to specify the data source, the HtmlSelect control and its DataTextField property automatically bind to the specified data source control. Therefore, you do not need to explicitly call the DataBind method.

The following code example demonstrates how to use the DataSource and DataTextField properties to specify the field from the data source to bind to the ListItem.Text property of each item in the HtmlSelect control.

<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %>

<!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>
    <title> HtmlSelect Example </title>
<script runat="server">

      Sub Page_Load (sender As Object, e As EventArgs)

        ' Bind the HtmlSelect control to a data source when the page is initially loaded.
        If Not IsPostBack Then

           ' Open a connection to the database and run the query.
           ' Note that the connection string may vary depending on your
           ' database server settings.
           Dim ConnectString As String = "server=localhost;database=pubs;integrated security=SSPI"
           Dim QueryString As String = "select * from authors"

           Dim myConnection As SqlConnection = New SqlConnection(ConnectString)
           Dim myCommand As SqlDataAdapter = New SqlDataAdapter(QueryString, myConnection)

           ' Create a dataset to store the query results.
           Dim ds As DataSet = New DataSet()
           myCommand.Fill(ds, "Authors")

           ' Bind the HtmlSelect control to the data source.
           Select1.DataSource = ds
           Select1.DataTextField = "au_fname"
           Select1.DataValueField = "au_fname"
           Select1.DataBind()

        End If

      End Sub

      Sub Button_Click (sender As Object, e As EventArgs)

         Dim i As Integer

         Label1.Text = "You selected:"

         For i = 0 To Select1.Items.Count - 1

            If Select1.Items(i).Selected Then
               Label1.Text = Label1.Text & "<br /> &nbsp;&nbsp; - " & Select1.Items(i).Text
            End If

         Next i

      End Sub

   </script>

</head>

<body>

   <form id="form1" runat="server">

      <h3> HtmlSelect Example </h3>

      Select items from the list. <br />
      Use the Control or Shift key to select multiple items. <br /><br />

      <select id="Select1"
              multiple="true" 
              runat="server"/>

      <br /><br />

      <button id="Button1"
              onserverclick="Button_Click"
              runat="server">

         Submit

      </button>

      <br /><br />

      <asp:Label id="Label1"
           runat="server"/>

   </form>

</body>

</html>

The following code example demonstrates how to use the DataSourceID and DataTextField properties to specify the field from the data source to bind to the ListItem.Value property of each item in the HtmlSelect control.

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server" language="vb">

  Sub SubmitButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
    Dim i As Integer
    ' Iterate through the list items in the 
    ' HtmlSelect control to find the selected item.
    For i = 0 To Select1.Items.Count - 1
      If Select1.Items(i).Selected Then
        ' Display the Value property of the selected item.
        ' This property is populated by the DataValueField property.
        Label1.Text = "The Product ID is " & Select1.Items(i).Value
      End If
    Next i

  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
    <title>HtmlSelect.DataValueField</title>
</head>
<body>
  <form id="Form1" runat="server">  

    <h3> HtmlSelect.DataValueField Example 2</h3>

    <p>Select an item from the list:</p>

    <select id="Select1"
      name="Select1"             
      datasourceid="SqlDataSource1"
      datatextfield="ProductName"
      datavaluefield="ProductID"
      runat="server">
    </select>

    <asp:sqldatasource id="SqlDataSource1" 
          connectionstring="workstation id=localhost;integrated security=SSPI;initial catalog=Northwind"
      selectcommand="SELECT * FROM [Products] Where ProductID <= 5"
      runat="server">
    </asp:sqldatasource>

    <asp:button id="SubmitButton"
      text="Submit"
      onclick="SubmitButton_Click"
      runat="Server">
    </asp:button>

    <br /><br />

    <asp:label id="Label1"
      runat="Server">
    </asp:label>

   </form>

</body>

</html>

.NET Framework
Available since 1.1
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