DataControlField.Visible Proprietà

Definizione

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

Ottiene o imposta un valore che indica se viene eseguito il rendering di un campo di controllo dati.Gets or sets a value indicating whether a data control field is rendered.

public:
 property bool Visible { bool get(); void set(bool value); };
public bool Visible { get; set; }
member this.Visible : bool with get, set
Public Property Visible As Boolean

Valore della proprietà

Boolean

true se DataControlField viene sottoposto a rendering; in caso contrario, false.true if the DataControlField is rendered; otherwise, false. Il valore predefinito è true.The default value is true.

Esempio

Nell'esempio di codice seguente viene illustrato come BoundField utilizzare ButtonField gli oggetti e, derivati da DataControlField , per visualizzare le righe in un DetailsView controllo.The following code example demonstrates how to use BoundField and ButtonField objects, which are derived from DataControlField, to display rows in a DetailsView control. La Visible proprietà dell' BoundField oggetto che visualizza la EmployeeID colonna è impostata su false e la colonna non viene sottoposta a rendering dal DetailsView controllo.The Visible property of the BoundField object that displays the EmployeeID column is set to false, and the column is not rendered by the DetailsView control.

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

<!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>ASP.NET Example</title>
</head>
<body>
  <form id="form1" runat="server">
    <asp:detailsview
      id="DetailsView1"
      runat="server"
      allowpaging="True"
      datasourceid="SqlDataSource1"
      autogeneraterows="False"
      width="312px"
      height="152px">
        <fields>
          <asp:boundfield
            visible="False"
            sortexpression="EmployeeID"
            datafield="EmployeeID">
          </asp:boundfield>

          <asp:boundfield
            sortexpression="LastName"
            datafield="LastName"
            headertext="LastName">
          </asp:boundfield>

          <asp:boundfield
            sortexpression="FirstName"
            datafield="FirstName"
            headertext="FirstName">
          </asp:boundfield>

          <asp:boundfield
            sortexpression="Title"
            datafield="Title"
            headertext="Title">
          </asp:boundfield>

          <asp:buttonfield text="Button">
            <controlstyle font-bold="True" forecolor="Red" />
          </asp:buttonfield>
        </fields>
    </asp:detailsview>

    <asp:sqldatasource
      id="SqlDataSource1"
      runat="server"
      selectcommand="SELECT * FROM Employees"
      connectionstring="<%$ ConnectionStrings:MyNorthwind%>">
    </asp:sqldatasource>

  </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">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>
  <form id="form1" runat="server">
    <asp:detailsview
      id="DetailsView1"
      runat="server"
      allowpaging="True"
      datasourceid="SqlDataSource1"
      autogeneraterows="False"
      width="312px"
      height="152px">
        <fields>
          <asp:boundfield
            visible="False"
            sortexpression="EmployeeID"
            datafield="EmployeeID">
          </asp:boundfield>

          <asp:boundfield
            sortexpression="LastName"
            datafield="LastName"
            headertext="LastName">
          </asp:boundfield>

          <asp:boundfield
            sortexpression="FirstName"
            datafield="FirstName"
            headertext="FirstName">
          </asp:boundfield>

          <asp:boundfield
            sortexpression="Title"
            datafield="Title"
            headertext="Title">
          </asp:boundfield>

          <asp:buttonfield text="Button">
            <controlstyle font-bold="True" forecolor="Red" />
          </asp:buttonfield>
        </fields>
    </asp:detailsview>

    <asp:sqldatasource
      id="SqlDataSource1"
      runat="server"
      selectcommand="SELECT * FROM Employees"
      connectionstring="<%$ ConnectionStrings:MyNorthwind%>">
    </asp:sqldatasource>

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

Commenti

Utilizzare la Visible proprietà per mostrare o nascondere DataControlField gli oggetti in un controllo con associazione a dati.Use the Visible property to show or hide DataControlField objects in a data-bound control.

Se la Visible proprietà è false , i valori dei dati non verranno visualizzati e non verrà eseguita una sequenza di andata e ritorno al client.If the Visible property is false, the data values are not displayed and do not make a round-trip to the client. Se si desidera eseguire il round trip dei dati per un campo non visibile, aggiungere il nome del campo alla DataKeyNames proprietà del controllo associato a dati.If you want to round-trip the data for a field that is not visible, add the field name to the DataKeyNames property of the data-bound control.

Si applica a