BaseDataList.DataMember Proprietà

Riferimento

Definizione

Spazio dei nomi:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Ottiene o imposta il membro di dati specifico in un'origine dati costituita da più membri per associarlo a un controllo di elenco dei dati.

public:
 property System::String ^ DataMember { System::String ^ get(); void set(System::String ^ value); };

public string DataMember { get; set; }

[System.Web.UI.Themeable(false)]
public string DataMember { get; set; }

member this.DataMember : string with get, set

[<System.Web.UI.Themeable(false)>]
member this.DataMember : string with get, set

Public Property DataMember As String

Valore della proprietà

String

Membro di dati di un'origine dati costituita da più membri. Il valore predefinito è Empty.

Attributi: ThemeableAttribute

Esempio

Nell'esempio di codice seguente viene illustrato come usare la DataMember proprietà per specificare la tabella in un oggetto da associare a un DataSet DataGrid controllo.


<%@ Page Language="C#" 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 runat="server">
    <title> BaseDataList DataMember Example </title>
<script runat="server">

      // Create sample data for the DataGrid control with two tables, 
      // Employee and Customer.
      DataSet CreateDataSet()
      {
    
         // Create a table to store employee values.
         DataTable EmployeeTable = new DataTable("Employee");
         DataRow TempDataRow;
   
         // Define the columns for the Employee table.
         EmployeeTable.Columns.Add(
            new DataColumn("EmployeeName", typeof(string)));
         EmployeeTable.Columns.Add(
            new DataColumn("EmployeeID", typeof(int)));

         // Populate the Employee table.
         for (int i=1; i<=5; i++) 
         {
            TempDataRow = EmployeeTable.NewRow();
            TempDataRow[0] = "Employee " + i.ToString();
            TempDataRow[1] = (i+1700);

            EmployeeTable.Rows.Add(TempDataRow);
         }

         // Create a table to store customer values.
         DataTable CustomerTable = new DataTable("Customer");

         // Define the columns for the Customer table.
         CustomerTable.Columns.Add(
            new DataColumn("CustomerName", typeof(string)));
         CustomerTable.Columns.Add(
            new DataColumn("CustomerID", typeof(int)));

         // Populate the Customer table.
         for (int i=1; i<=5; i++) 
         {
            TempDataRow = CustomerTable.NewRow();
            TempDataRow[0] = "Customer " + i.ToString();
            TempDataRow[1] = (i+1700);

            CustomerTable.Rows.Add(TempDataRow);
         }

         // Create a DataSet and add the Employee and Customer tables.
         DataSet ds = new DataSet();
         ds.Tables.Add(EmployeeTable);
         ds.Tables.Add(CustomerTable);

         return ds;

      }
             
      void Page_Load(Object sender, EventArgs e) 
      {

         // The data source only needs to be bound to the DataList  
         // control the first time the page is accessed.    
         if(!IsPostBack)
         {

            // Create the sample data for the DataList control.
            ItemsGrid.DataSource = CreateDataSet();

            // The data source in this example contains multiple tables. 
            // Specify which table to display in the DataList control. 
            ItemsGrid.DataMember = "Customer";

            // Bind the data source to the control.
            ItemsGrid.DataBind();

         }

      }

      void Index_Change(Object sender, EventArgs e) 
      {

         // Create the sample data for the DataList control.
         ItemsGrid.DataSource = CreateDataSet();

         // The data source in this example contains multiple tables. 
         // Specify which table to display in the DataList control 
         // based on the user's selection from the DropDownList control. 
         ItemsGrid.DataMember = SourceList.SelectedItem.Text;

         // Bind the data source to the control. 
         ItemsGrid.DataBind();

      }

   </script>

</head>
<body>

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

      <h3> BaseDataList DataMember Example </h3>
      
      <asp:DataGrid id="ItemsGrid"
           AutoGenerateColumns="True" 
           runat="server">

         <headerstyle backcolor="#00aaaa"/>
</asp:DataGrid>

      <br /><br />

      Select the data source: <br />

      <asp:DropDownList id="SourceList"
           AutoPostBack="True"
           OnSelectedIndexChanged="Index_Change"
           runat="server">

         <asp:Listitem Selected="True">Customer</asp:Listitem>
         <asp:Listitem>Employee</asp:Listitem>

      </asp:DropDownList>

   </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 runat="server">
    <title> BaseDataList DataMember Example </title>
<script runat="server">

      ' Create sample data for the DataGrid control with two tables,
      ' Employee and Customer.
      Function CreateDataSet() As DataSet
    
         ' Create a table to store employee values.
         Dim EmployeeTable As DataTable = New DataTable("Employee")
         Dim TempDataRow As DataRow
   
         ' Define the columns for the Employee table.
         EmployeeTable.Columns.Add( _
            New DataColumn("EmployeeName", GetType(String)))
         EmployeeTable.Columns.Add( _
            New DataColumn("EmployeeID", GetType(Integer)))

         ' Populate the Employee table.
         Dim i As Integer

         For i=1 To 5 
         
            TempDataRow = EmployeeTable.NewRow()
            TempDataRow(0) = "Employee " & i.ToString()
            TempDataRow(1) = (i+1700)

            EmployeeTable.Rows.Add(TempDataRow)

         Next

         ' Create a table to store customer values.
         Dim CustomerTable As DataTable = New DataTable("Customer")

         ' Define the columns for the Customer table.
         CustomerTable.Columns.Add( _
            New DataColumn("CustomerName", GetType(String)))
         CustomerTable.Columns.Add( _
            New DataColumn("CustomerID", GetType(Integer)))

         ' Populate the Customer table.
         For i=1 To 5  

            TempDataRow = CustomerTable.NewRow()
            TempDataRow(0) = "Customer " & i.ToString()
            TempDataRow(1) = (i+1700)

            CustomerTable.Rows.Add(TempDataRow)
         
         Next

         ' Create a DataSet and add the Employee and Customer tables.
         Dim ds As DataSet = New DataSet()
         ds.Tables.Add(EmployeeTable)
         ds.Tables.Add(CustomerTable)

         Return ds

      End Function
             
      Sub Page_Load(sender As Object, e As EventArgs) 

         ' The data source only needs to be bound to the DataList  
         ' control the first time the page is accessed.    
         If Not IsPostBack Then

            ' Create the sample data for the DataList control.
            ItemsGrid.DataSource = CreateDataSet()

            ' The data source in this example contains multiple tables.  
            ' Specify which table to display in the DataList control. 
            ItemsGrid.DataMember = "Customer"

            ' Bind the data source to the control.
            ItemsGrid.DataBind()

         End If

      End Sub

      Sub Index_Change(sender As Object, e As EventArgs) 

         ' Create the sample data for the DataList control.
         ItemsGrid.DataSource = CreateDataSet()

         ' The data source in this example contains multiple tables. 
         ' Specify which table to display in the DataList control 
         ' based on the user's selection from the DropDownList control. 
         ItemsGrid.DataMember = SourceList.SelectedItem.Text

         ' Bind the data source to the control. 
         ItemsGrid.DataBind()

      End Sub

   </script>

</head>
<body>

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

      <h3> BaseDataList DataMember Example </h3>
      
      <asp:DataGrid id="ItemsGrid"
           AutoGenerateColumns="True" 
           runat="server">

         <headerstyle backcolor="#00aaaa"/>
</asp:DataGrid>

      <br /><br />

      Select the data source: <br />

      <asp:DropDownList id="SourceList"
           AutoPostBack="True"
           OnSelectedIndexChanged="Index_Change"
           runat="server">

         <asp:Listitem Selected="True">Customer</asp:Listitem>
         <asp:Listitem>Employee</asp:Listitem>

      </asp:DropDownList>

   </form>
 
</body>

</html>

Commenti

Utilizzare la DataMember proprietà per specificare un membro da un'origine dati multimember per associare al controllo elenco. Ad esempio, se si dispone di un'origine DataSource dati con più tabelle specificate nella proprietà, utilizzare la DataMember proprietà per specificare la tabella da associare a un controllo elenco dati.

Questa proprietà non può essere impostata da temi oppure temi di fogli di stile. Per altre informazioni, vedere ThemeableAttribute e ASP.NET Temi e skin.

Si applica a

Vedi anche

DataSource