DataControlFieldCollection.Add(DataControlField) Metodo

  • Riferimento

Definizione

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

Aggiunge l'oggetto DataControlField specificato alla fine dell'insieme.

public:
 void Add(System::Web::UI::WebControls::DataControlField ^ field);
public void Add (System.Web.UI.WebControls.DataControlField field);
member this.Add : System.Web.UI.WebControls.DataControlField -> unit
Public Sub Add (field As DataControlField)

Parametri

field
DataControlField

Oggetto DataControlField da aggiungere all'insieme.

Esempio

Nell'esempio di codice seguente viene illustrato come usare il Add metodo per aggiungere dinamicamente un CheckBoxField oggetto a un GridView controllo.


<%@ 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 Page_Load(Object sender, EventArgs e)
  {

    // The columns need to be created only the first time
    // the page is loaded.
    if(!IsPostBack)
    {
  
      // Dynamically create columns to display the desired
      // fields from the data source. Columns that are 
      // dynamically added to the GridView control are not persisted 
      // across posts and must be recreated each time the page is 
      // loaded.
  
      // Create a BoundField object to display an author's last name.
      BoundField lastNameBoundField = new BoundField();
      lastNameBoundField.DataField = "au_lname";
      lastNameBoundField.HeaderText = "Last Name";
    
      // Create a CheckBoxField object to indicate whether the author
      // is on contract.
      CheckBoxField contractCheckBoxField = new CheckBoxField();
      contractCheckBoxField.DataField = "contract";
      contractCheckBoxField.HeaderText = "Contract";
    
      // Add the columns to the Columns collection of the
      // GridView control.
      AuthorsGridView.Columns.Add(lastNameBoundField);
      AuthorsGridView.Columns.Add(contractCheckBoxField);

    }
  
  }

</script>

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

      <asp:gridview id="AuthorsGridView" 
        datasourceid="AuthorsSqlDataSource" 
        autogeneratecolumns="False"
        runat="server">                
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects -->
      <!-- to the Pubs sample database.                        -->
      <asp:sqldatasource id="AuthorsSqlDataSource"  
        selectcommand="SELECT [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
        connectionstring="server=localhost;database=pubs;integrated security=SSPI"
        runat="server">
      </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">
<script runat="server">

  Sub Page_Load(sender as Object, e As EventArgs)
  
    ' The columns need to be created only the first time
    ' the page is loaded.
    If Not IsPostBack Then

      ' Dynamically create columns to display the desired
      ' fields from the data source. Columns that are 
      ' dynamically added to the GridView control are not persisted 
      ' across posts and must be recreated each time the page is 
      ' loaded.
  
      ' Create a BoundField object to display an author's last name.
      Dim lastNameBoundField As BoundField = New BoundField
      lastNameBoundField.DataField = "au_lname"
      lastNameBoundField.HeaderText = "Last Name"
    
      ' Create a CheckBoxField object to indicate whether the author
      ' is on contract.
      Dim contractCheckBoxField As CheckBoxField = New CheckBoxField
      contractCheckBoxField.DataField = "contract"
      contractCheckBoxField.HeaderText = "Contract"
    
      ' Add the columns to the Columns collection of the
      ' GridView control.
      AuthorsGridView.Columns.Add(lastNameBoundField)
      AuthorsGridView.Columns.Add(contractCheckBoxField)

    End If
  
  End Sub

</script>

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

      <asp:gridview id="AuthorsGridView" 
        datasourceid="AuthorsSqlDataSource" 
        autogeneratecolumns="False"
        runat="server">                
      </asp:gridview>
            
      <!-- This example uses Microsoft SQL Server and connects -->
      <!-- to the Pubs sample database.                        -->
      <asp:sqldatasource id="AuthorsSqlDataSource"  
        selectcommand="SELECT [au_lname], [au_fname], [address], [city], [state], [zip], [contract] FROM [authors]"
        connectionstring="server=localhost;database=pubs;integrated security=SSPI"
        runat="server">
      </asp:sqldatasource>
            
    </form>
  </body>
</html>

Commenti

Utilizzare il Add metodo per aggiungere un DataControlField oggetto alla fine dell'insieme. Questa implementazione del metodo accetta l'oggetto DataControlField specificato dal field parametro e lo aggiunge alla raccolta.

Si applica a

Vedi anche