DataList.ShowHeader Proprietà

  • Riferimento

Definizione

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

Ottiene o imposta un valore che indica se la sezione dell'intestazione viene visualizzata nel controllo DataList.

public:
 virtual property bool ShowHeader { bool get(); void set(bool value); };
[System.ComponentModel.Bindable(true)]
public virtual bool ShowHeader { get; set; }
public virtual bool ShowHeader { get; set; }
[<System.ComponentModel.Bindable(true)>]
member this.ShowHeader : bool with get, set
member this.ShowHeader : bool with get, set
Public Overridable Property ShowHeader As Boolean

Valore della proprietà

Boolean

true se l'intestazione viene visualizzata; in caso contrario, false. Il valore predefinito è true. Questa proprietà viene tuttavia esaminata solo quando il valore della proprietà HeaderTemplate è diverso da null.

Attributi
BindableAttribute

Esempio

Nell'esempio di codice seguente viene illustrato come usare la ShowHeader proprietà per visualizzare la sezione intestazione nel DataList controllo.

Nota

L'esempio di codice seguente usa il modello di codice a file singolo e potrebbe non funzionare correttamente se copiato direttamente in un file code-behind. Questo esempio di codice deve essere copiato in un file di testo vuoto con un'estensione .aspx. Per altre informazioni sul modello di codice Web Forms, vedere ASP.NET modello di codice della pagina Web Forms.


<%@ 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" >
   <script runat="server">
 
      ICollection CreateDataSource() 
      {
      
         // Create sample data for the DataList control.
         DataTable dt = new DataTable();
         DataRow dr;
 
         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
         dt.Columns.Add(new DataColumn("StringValue", typeof(String)));
         dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
         dt.Columns.Add(new DataColumn("ImageValue", typeof(String)));
 
         // Populate the table with sample values.
         for (int i = 0; i < 9; i++) 
         {
            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = "Description for item " + i.ToString();
            dr[2] = 1.23 * (i + 1);
            dr[3] = "Image" + i.ToString() + ".jpg";
 
            dt.Rows.Add(dr);
         }
 
         DataView dv = new DataView(dt);
         return dv;
      }
  
      void Page_Load(Object sender, EventArgs e) 
      {

         // Load sample data only once, when the page is first loaded.
         if (!IsPostBack) 
         {
            ItemsList.DataSource = CreateDataSource();
            ItemsList.DataBind();
         }

      }

      void Selection_Change(Object sender, EventArgs e)
      {

         // Set whether to display the header and footer sections
         // of the DataList control.
         ItemsList.ShowHeader = ShowHeaderCheckBox.Checked;
         ItemsList.ShowFooter = ShowFooterCheckBox.Checked;

      }
 
   </script>
 
<head runat="server">
    <title>DataList ShowHeader and ShowFooter Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataList ShowHeader and ShowFooter Example</h3>

      Select whether to show or hide the header and footer sections.

      <br /><br />
 
      <asp:DataList id="ItemsList"
           BorderColor="black"
           CellPadding="5"
           CellSpacing="5"
           RepeatDirection="Vertical"
           RepeatLayout="Table"
           RepeatColumns="3"
           ShowHeader="True"
           ShowFooter="True"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <FooterStyle BackColor="#aaaadd">
         </FooterStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <HeaderTemplate>

            List of items

         </HeaderTemplate>

         <FooterTemplate>

            <asp:Image id="FooterImage"
                 GenerateEmptyAlternateText='true'
                 ImageUrl='FooterImage.jpg'
                 runat="server"/>

         </FooterTemplate>
               
         <ItemTemplate>

            Description: <br />
            <%# DataBinder.Eval(Container.DataItem, "StringValue") %>

            <br />

            Price: <%# DataBinder.Eval(Container.DataItem, "CurrencyValue", "{0:c}") %>

            <br />

            <asp:Image id="ProductImage"
                 AlternateText='<%# DataBinder.Eval(Container.DataItem, "StringValue") %>'
                 ImageUrl='<%# DataBinder.Eval(Container.DataItem, "ImageValue") %>'
                 runat="server"/>

         </ItemTemplate>
 
      </asp:DataList>

<hr />

      <table cellpadding="5">

         <tr>

            <td>

               <asp:CheckBox id="ShowHeaderCheckBox"
                    Text="Show header section"
                    Checked="True"
                    AutoPostBack="True"
                    OnCheckedChanged="Selection_Change"
                    runat="server"/>
 
            </td>

            <td>

               <asp:CheckBox id="ShowFooterCheckBox"
                    Text="Show footer section"
                    Checked="True"
                    AutoPostBack="True"
                    OnCheckedChanged="Selection_Change"
                    runat="server"/>

            </td>

         </tr>

      </table>
 
   </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" >
   <script runat="server">
 
      Function CreateDataSource() As ICollection 
      
         ' Create sample data for the DataList control.
         Dim dt As DataTable = New DataTable()
         dim dr As DataRow
 
         ' Define the columns of the table.
         dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
         dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
         dt.Columns.Add(New DataColumn("CurrencyValue", GetType(Double)))
         dt.Columns.Add(New DataColumn("ImageValue", GetType(String)))
 
         ' Populate the table with sample values.
         Dim i As Integer

         For i = 0 To 8 

            dr = dt.NewRow()
 
            dr(0) = i
            dr(1) = "Description for item " & i.ToString()
            dr(2) = 1.23 * (i + 1)
            dr(3) = "Image" & i.ToString() & ".jpg"
 
            dt.Rows.Add(dr)

         Next i
 
         Dim dv As DataView = New DataView(dt)
         Return dv

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

         ' Load sample data only once, when the page is first loaded.
         If Not IsPostBack Then 
     
            ItemsList.DataSource = CreateDataSource()
            ItemsList.DataBind()
         
         End If

      End Sub

      Sub Selection_Change(sender As Object, e As EventArgs)

         ' Set whether to display the header and footer sections
         ' of the DataList control.
         ItemsList.ShowHeader = ShowHeaderCheckBox.Checked
         ItemsList.ShowFooter = ShowFooterCheckBox.Checked

      End Sub
 
   </script>
 
<head runat="server">
    <title>DataList ShowHeader and ShowFooter Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataList ShowHeader and ShowFooter Example</h3>

      Select whether to show or hide the header and footer sections.

      <br /><br />
 
      <asp:DataList id="ItemsList"
           BorderColor="black"
           CellPadding="5"
           CellSpacing="5"
           RepeatDirection="Vertical"
           RepeatLayout="Table"
           RepeatColumns="3"
           ShowHeader="True"
           ShowFooter="True"
           runat="server">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <FooterStyle BackColor="#aaaadd">
         </FooterStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <HeaderTemplate>

            List of items

         </HeaderTemplate>

         <FooterTemplate>

            <asp:Image id="FooterImage"
                 GenerateEmptyAlternateText='true'
                 ImageUrl='FooterImage.jpg'
                 runat="server"/>

         </FooterTemplate>
               
         <ItemTemplate>

            Description: <br />
            <%# DataBinder.Eval(Container.DataItem, "StringValue") %>

            <br />

            Price: <%# DataBinder.Eval(Container.DataItem, "CurrencyValue", "{0:c}") %>

            <br />

            <asp:Image id="ProductImage"
                 AlternateText='<%# DataBinder.Eval(Container.DataItem, "StringValue") %>'
                 ImageUrl='<%# DataBinder.Eval(Container.DataItem, "ImageValue") %>'
                 runat="server"/>

         </ItemTemplate>
 
      </asp:DataList>

<hr />

      <table cellpadding="5">

         <tr>

            <td>

               <asp:CheckBox id="ShowHeaderCheckBox"
                    Text="Show header section"
                    Checked="True"
                    AutoPostBack="True"
                    OnCheckedChanged="Selection_Change"
                    runat="server"/>
 
            </td>

            <td>

               <asp:CheckBox id="ShowFooterCheckBox"
                    Text="Show footer section"
                    Checked="True"
                    AutoPostBack="True"
                    OnCheckedChanged="Selection_Change"
                    runat="server"/>

            </td>

         </tr>

      </table>
 
   </form>
 
</body>
</html>

Commenti

Utilizzare la ShowHeader proprietà per specificare se la sezione intestazione viene visualizzata nel DataList controllo.

È possibile controllare l'aspetto della sezione intestazione impostando la HeaderStyle proprietà. Il contenuto della sezione intestazione è controllato dalla HeaderTemplate proprietà .

Si applica a

Vedi anche