DataControlField.Visible DataControlField.Visible DataControlField.Visible DataControlField.Visible Property

Definizione

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

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.

Esempi

Nell'esempio di codice seguente viene illustrato come BoundField utilizzare ButtonField gli oggetti e, derivati da DataControlField, per visualizzare le DetailsView righe in un 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 EmployeeID proprietà falsedell'oggetto che visualizza la colonna è impostata su e la colonna non viene sottoposta a rendering DetailsView dal controllo. BoundFieldThe 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