GridView.HeaderRow Proprietà

  • Riferimento

Definizione

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

Ottiene un oggetto GridViewRow che rappresenta la riga dell'intestazione in un controllo GridView.

public:
 virtual property System::Web::UI::WebControls::GridViewRow ^ HeaderRow { System::Web::UI::WebControls::GridViewRow ^ get(); };
[System.ComponentModel.Browsable(false)]
public virtual System.Web.UI.WebControls.GridViewRow HeaderRow { get; }
[<System.ComponentModel.Browsable(false)>]
member this.HeaderRow : System.Web.UI.WebControls.GridViewRow
Public Overridable ReadOnly Property HeaderRow As GridViewRow

Valore della proprietà

GridViewRow

Un oggetto GridViewRow che rappresenta la riga dell'intestazione in un controllo GridView.

Attributi
BrowsableAttribute

Esempio

Nell'esempio seguente viene illustrato come usare la proprietà per modificare a livello di codice il HeaderRow colore del carattere della riga di intestazione in base alla direzione di ordinamento.


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

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  
  void CustomersGridView_DataBound(Object sender, EventArgs e)
  {
    
    // Get the header row.
    GridViewRow headerRow = CustomersGridView.HeaderRow;   
    
    // Get the footer row.
    GridViewRow footerRow = CustomersGridView.FooterRow; 

    // Set the font color of the header and footer rows
    // based on the sort direction. 
    switch (CustomersGridView.SortDirection)
    {
      case SortDirection.Ascending:
        headerRow.ForeColor = System.Drawing.Color.Green;
        footerRow.ForeColor = System.Drawing.Color.Green;
        break;
      case SortDirection.Descending:
        headerRow.ForeColor = System.Drawing.Color.Red;
        footerRow.ForeColor = System.Drawing.Color.Red;
        break;
      default:
        headerRow.ForeColor = System.Drawing.Color.Black;
        footerRow.ForeColor = System.Drawing.Color.Black;
        break;
    }

    // Display the sort order in the footer row.
    footerRow.Cells[0].Text = "Sort Order = " + CustomersGridView.SortDirection.ToString();
      
  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView HeaderRow and FooterRow Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView HeaderRow and FooterRow Example</h3>

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSource" 
        autogeneratecolumns="true"
        emptydatatext="No data available." 
        allowsorting="true"
        allowpaging="true" 
        showheader="true"
        showfooter="true"
        ondatabound="CustomersGridView_DataBound"    
        runat="server">
        
        <headerstyle backcolor="LightCyan"
          forecolor="MediumBlue"/>
                    
        <footerstyle backcolor="LightCyan"
          forecolor="MediumBlue"/>
                        
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
        
    </form>
  </body>
</html>


<%@ Page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
  
  Sub CustomersGridView_DataBound(ByVal sender As Object, ByVal e As EventArgs)
      
    ' Get the header row.
    Dim headerRow As GridViewRow = CustomersGridView.HeaderRow
    
    ' Get the footer row.
    Dim footerRow As GridViewRow = CustomersGridView.FooterRow

    ' Set the font color of the header and footer rows
    ' based on the sort direction. 
    Select Case CustomersGridView.SortDirection

      Case SortDirection.Ascending
        headerRow.ForeColor = System.Drawing.Color.Green
        footerRow.ForeColor = System.Drawing.Color.Green
      Case SortDirection.Descending
        headerRow.ForeColor = System.Drawing.Color.Red
        footerRow.ForeColor = System.Drawing.Color.Red
      Case Else
        headerRow.ForeColor = System.Drawing.Color.Black
        footerRow.ForeColor = System.Drawing.Color.Black
        
    End Select

    ' Display the sort order in the footer row.
    footerRow.Cells(0).Text = "Sort Order = " & CustomersGridView.SortDirection.ToString()
      
  End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView HeaderRow and FooterRow Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView HeaderRow and FooterRow Example</h3>

      <asp:gridview id="CustomersGridView" 
        datasourceid="CustomersSource" 
        autogeneratecolumns="true"
        emptydatatext="No data available." 
        allowsorting="true"
        allowpaging="true" 
        showheader="true"
        showfooter="true"
        ondatabound="CustomersGridView_DataBound"    
        runat="server">
        
        <headerstyle backcolor="LightCyan"
          forecolor="MediumBlue"/>
                    
        <footerstyle backcolor="LightCyan"
          forecolor="MediumBlue"/>
                        
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects  -->
      <!-- to the Northwind sample database. Use an ASP.NET     -->
      <!-- expression to retrieve the connection string value   -->
      <!-- from the Web.config file.                            -->
      <asp:sqldatasource id="CustomersSource"
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
        
    </form>
  </body>
</html>

Commenti

Utilizzare la HeaderRow proprietà per accedere a livello di codice all'oggetto GridViewRow che rappresenta la riga di intestazione in un GridView controllo.

Nota

La HeaderRow proprietà è disponibile solo dopo che il GridView controllo crea la riga di intestazione nell'evento RowCreated .

Questa proprietà viene comunemente usata quando è necessario modificare a livello di codice la riga di intestazione, ad esempio quando si aggiunge contenuto personalizzato. Tutte le modifiche apportate alla HeaderRow proprietà devono essere eseguite dopo il rendering del GridView controllo. In caso contrario, il GridView controllo sovrascriverà eventuali modifiche.

Si applica a

Vedi anche