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HtmlSelect.DataMember Propriedade

Definição

Obtém ou define o conjunto de dados para associar o controle HtmlSelect de uma propriedade DataSource com vários conjuntos de dados.

public:
 virtual property System::String ^ DataMember { System::String ^ get(); void set(System::String ^ value); };
public virtual string DataMember { get; set; }
member this.DataMember : string with get, set
Public Overridable Property DataMember As String

Valor da propriedade

String

O conjunto de dados a serem associados ao HtmlSelect controle de um DataSource com vários conjuntos de dados. O valor padrão é uma cadeia de caracteres vazia (""), que indica que a propriedade não foi definida.

Exceções

A propriedade DataMember é definida durante a fase de associação de dados do controle HtmlSelect.

Exemplos

O exemplo de código a seguir demonstra como usar a DataMember propriedade para especificar um conjunto de dados a serem associados ao HtmlSelect controle de uma DataSource propriedade com vários conjuntos de dados.

<%@ Page Language="C#" 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">

      void Page_Load (Object sender, EventArgs e)
      {

         // Bind the HtmlSelect control to a data source when the page is initially loaded.
         if (!IsPostBack)
         {
      
            // Create a data set to store the tables.
            DataSet ds = new DataSet("TitleDataSet");
            DataRow dr; 

            // Create the authors table with a single column.
            DataTable authors = new DataTable("Authors");            
            authors.Columns.Add(new DataColumn("LName", typeof(string)));                    
 
            // Add the authors table to the data set.
            ds.Tables.Add(authors);

            // Create sample data in the authors table.
            for (int i = 0; i < 9; i++) 
            {
               // Create a new row for the authors table.
               dr = authors.NewRow();

               // Add data to the LName column (column 0 in the row).
               dr[0] = "Author " + i.ToString();

               // Insert the row into the authors table.   
               authors.Rows.Add(dr);
            }
  
            // Create the titles table with a single column.
            DataTable titles = new DataTable("Titles");            
            titles.Columns.Add(new DataColumn("BookTitle", typeof(string)));                    
 
            // Add the titles table to the data set.
            ds.Tables.Add(titles);

            // Create sample data in the titles table.
            for (int i = 0; i < 9; i++) 
            {
               // Create a new row for the titles table.
               dr = titles.NewRow();

               // Add data to the BookTitle column (column 0 in the row).
               dr[0] = "Title " + i.ToString();

              // Insert the row into the titles table.   
              titles.Rows.Add(dr);
            }

            // Bind the HtmlSelect control to the data source.
            Select1.DataSource = ds;
            Select1.DataMember = "Titles";
            Select1.DataTextField = "BookTitle";
            Select1.DataBind();

         }

      }

      void Button_Click (Object sender, EventArgs e)
      {
       
         // Display the selected items. 
         Label1.Text = "You selected:";

         for (int i=0; i<=Select1.Items.Count - 1; i++)
         {
            if (Select1.Items[i].Selected)
               Label1.Text += "<br />    - " + Select1.Items[i].Text;
         }

      }

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

<!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
 
            Dim i As Integer
      
            ' Create a data set to store the tables.
            Dim ds As DataSet = New DataSet("TitleDataSet")
            Dim dr As DataRow 

            ' Create the authors table with a single column.
            Dim authors As DataTable = New DataTable("Authors")            
            authors.Columns.Add(New DataColumn("LName", GetType(String)))                    
 
            ' Add the authors table to the data set.
            ds.Tables.Add(authors)

            ' Create sample data in the authors table.
            For i = 0 To 9 
           
               ' Create a new row for the authors table.
               dr = authors.NewRow()

               ' Add data to the LName column (column 0 in the row).
               dr(0) = "Author " & i.ToString()

               ' Insert the row into the authors table.   
               authors.Rows.Add(dr)

            Next i
  
            ' Create the titles table with a single column.
            Dim titles As DataTable = New DataTable("Titles")            
            titles.Columns.Add(New DataColumn("BookTitle", GetType(String)))                    
 
            ' Add the titles table to the data set.
            ds.Tables.Add(titles)

            ' Create sample data in the titles table.
            For i = 0 To 9
            
               ' Create a new row for the titles table.
               dr = titles.NewRow()

               ' Add data to the BookTitle column (column 0 in the row).
               dr(0) = "Title " & i.ToString()

               ' Insert the row into the titles table.   
               titles.Rows.Add(dr)

            Next i

            ' Bind the HtmlSelect control to the data source.
            Select1.DataSource = ds
            Select1.DataMember = "Titles"
            Select1.DataTextField = "BookTitle"
            Select1.DataBind()

         End If

      End Sub

      Sub Button_Click (sender As Object, e As EventArgs)

         Dim i As Integer
       
         ' Display the selected items. 
         Label1.Text = "You selected:"

         For i=0 To Select1.Items.Count - 1
      
            If Select1.Items(i).Selected Then
               Label1.Text = Label1.Text & "<br />    - " & 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>

Comentários

Se a DataSource propriedade contiver vários conjuntos de dados, use a DataMember propriedade para especificar qual conjunto de dados associar ao controle. Por exemplo, se você tiver um System.Data.DataSet objeto com várias tabelas, use essa propriedade para indicar qual tabela associar ao controle.

Depois de especificar a fonte de dados a ser associada ao controle, você poderá especificar quais campos da fonte de dados a serem associados à ListItem.Text e ListItem.Value às propriedades de cada item no controle definindo as propriedades e DataValueField as DataTextField propriedades, respectivamente.

Aplica-se a

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