FormViewCommandEventArgs.CommandSource Propriété

  • Référence

Définition

Espace de noms:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Obtient le contrôle qui a déclenché l'événement.

public:
 property System::Object ^ CommandSource { System::Object ^ get(); };
public object CommandSource { get; }
member this.CommandSource : obj
Public ReadOnly Property CommandSource As Object

Valeur de propriété

Object

Object qui représente le contrôle qui a déclenché l'événement.

Exemples

L’exemple suivant montre comment utiliser la CommandSource propriété pour accéder aux propriétés du contrôle de bouton qui a déclenché l’événement ItemCommand .

Important

Cet exemple comprend une zone de texte qui accepte une entrée d'utilisateur, ce qui constitue une menace potentielle pour la sécurité. Par défaut, les pages web ASP.NET vérifient que l’entrée d’utilisateur n’inclut pas de script ou d’éléments HTML. Pour plus d’informations, consultez Vue d’ensemble des attaques de script.


<%@ 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 ProductFormView_ItemCommand(Object sender, FormViewCommandEventArgs e)
  {

    // The ItemCommand event is raised when any button within
    // the FormView control is clicked. Use the CommandName property 
    // to determine which button was clicked. 
    if (e.CommandName == "Add")
    {

      // Add the product to the ListBox control. 
      
      // Use the Row property to retrieve the data row.
      FormViewRow row = ProductFormView.Row;
      
      // Retrieve the ProductNameLabel control from
      // the data row.
      Label productNameLabel = (Label)row.FindControl("ProductNameLabel");

      // Retrieve the QuantityTextBox control from
      // the data row.
      TextBox quantityTextBox = (TextBox)row.FindControl("QuantityTextBox");

      if (productNameLabel != null && quantityTextBox != null)
      {    
        // Get the product name from the ProductNameLabel control.
        string name = productNameLabel.Text;
        
        // Get the quantity from the QuantityTextBox control.
        string quantity = quantityTextBox.Text;

        // Create the text to display in the ListBox control.
        string description = name + " - " + quantity + " Qty";

        // Create a ListItem object using the description and
        // product name.
        ListItem item = new ListItem(description, name);

        // Add the ListItem object to the ListBox.
        ProductListBox.Items.Add(item);

        // Use the CommandSource property to retrieve
        // the Add button. Disable the button after
        // the user adds the currently displayed employee
        // name to the ListBox control.
        Button addButton = (Button)e.CommandSource;
        addButton.Enabled = false;
      }

    }

  }

  void ProductFormView_DataBound(Object sender, EventArgs e)
  {
    
    // To prevent the user from adding duplicate items, 
    // disable the Add button if the item being bound to the 
    // FormView control is already in the ListBox control.
    
    // Use the Row property to retrieve the data row.
    FormViewRow row = ProductFormView.Row;

    // Retrieve the Add button from the data row.
    Button addButton = (Button)row.FindControl("AddButton");

    // Retrieve the ProductNameLabel control from
    // data row.
    Label productNameLabel = (Label)row.FindControl("ProductNameLabel");

    if (addButton != null && productNameLabel != null)
    {
      // Get the product name from the ProductNameLabel 
      // control.
      string name = productNameLabel.Text;

      // Use the FindByValue method to determine whether
      // the ListBox control already contains an entry for
      // the item.
      ListItem item = ProductListBox.Items.FindByValue(name);

      // Disable the Add button if the ListBox control
      // already contains the item.
      if (item != null)
      {
        addButton.Enabled = false;
      }
      else
      {
        addButton.Enabled = true;
      }
    }

  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewCommandEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewCommandEventArgs Example</h3>
                       
      <asp:formview id="ProductFormView"
        datasourceid="ProductSource"
        allowpaging="true"
        datakeynames="ProductID"
        onitemcommand="ProductFormView_ItemCommand"
        ondatabound="ProductFormView_DataBound"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td style="width:400px">
                <b>Description:</b>
                <asp:label id="ProductNameLabel"
                  text='<%# Eval("ProductName") %>'
                  runat='server'/>
                <br/>      
                <b>Price:</b>
                <asp:label id="PriceLabel"
                  text='<%# Eval("UnitPrice", "{0:c}") %>'
                  runat='server'/>
                <br/>  
                <asp:textbox id="QuantityTextBox"
                  width="50px"
                  maxlength="3" 
                  runat="server"/> Qty                   
              </td>
            </tr>
            <tr>
              <td>
                <asp:requiredfieldvalidator ID="QuantityRequiredValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter a quantity."
                  display="Static"
                  runat="server"/>
                <br/>
                <asp:CompareValidator id="QuantityCompareValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter an integer value."
                  display="Static"
                  type="Integer"
                  operator="DataTypeCheck"  
                  runat="server"/>    
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="AddButton"
                  text="Add"
                  commandname="Add"
                  runat="server"/>
              </td>
            </tr>
          </table>
        
        </itemtemplate>
                  
      </asp:formview>
      
      <br/><br/><hr/>
      
      Items:<br/>
      <asp:listbox id="ProductListBox"
        runat="server"/>
          
      <!-- 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="ProductSource"
        selectcommand="Select [ProductID], [ProductName], [UnitPrice] From [Products]"
        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 ProductFormView_ItemCommand(ByVal sender As Object, ByVal e As FormViewCommandEventArgs)

    ' The ItemCommand event is raised when any button within
    ' the FormView control is clicked. Use the CommandName property 
    ' to determine which button was clicked. 
    If e.CommandName = "Add" Then

      ' Add the product to the ListBox control. 
      
      ' Use the Row property to retrieve the data row.
      Dim row As FormViewRow = ProductFormView.Row
      
      ' Retrieve the ProductNameLabel control from
      ' the data row.
      Dim productNameLabel As Label = CType(row.FindControl("ProductNameLabel"), Label)

      ' Retrieve the QuantityTextBox control from
      ' the data row.
      Dim quantityTextBox As TextBox = CType(row.FindControl("QuantityTextBox"), TextBox)

      If productNameLabel IsNot Nothing And quantityTextBox IsNot Nothing Then
          
        ' Get the product name from the ProductNameLabel control.
        Dim name As String = productNameLabel.Text
        
        ' Get the quantity from the QuantityTextBox control.
        Dim quantity As String = quantityTextBox.Text

        ' Create the text to display in the ListBox control.
        Dim description As String = name & " - " & quantity & " Qty"

        ' Create a ListItem object using the description and
        ' product name.
        Dim item As new ListItem(description, name)

        ' Add the ListItem object to the ListBox.
        ProductListBox.Items.Add(item)

        ' Use the CommandSource property to retrieve
        ' the Add button. Disable the button after
        ' the user adds the currently displayed employee
        ' name to the ListBox control.
        Dim addButton As Button = CType(e.CommandSource, Button)
        addButton.Enabled = False
        
      End If

    End If

  End Sub

  Sub ProductFormView_DataBound(ByVal sender As Object, ByVal e As EventArgs)
    
    ' To prevent the user from adding duplicate items, 
    ' disable the Add button if the item being bound to the 
    ' FormView control is already in the ListBox control.
    
    ' Use the Row property to retrieve the data row.
    Dim row As FormViewRow = ProductFormView.Row

    ' Retrieve the Add button from the data row.
    Dim addButton As Button = CType(row.FindControl("AddButton"), Button)

    ' Retrieve the ProductNameLabel control from
    ' data row.
    Dim productNameLabel As Label = CType(row.FindControl("ProductNameLabel"), Label)

    If addButton IsNot Nothing And productNameLabel IsNot Nothing Then
    
      ' Get the product name from the ProductNameLabel 
      ' control.
      Dim name As String = productNameLabel.Text

      ' Use the FindByValue method to determine whether
      ' the ListBox control already contains an entry for
      ' the item.
      Dim item As ListItem = ProductListBox.Items.FindByValue(name)

      ' Disable the Add button if the ListBox control
      ' already contains the item.
      If item IsNot Nothing Then
      
        addButton.Enabled = False
      
      Else
      
        addButton.Enabled = True
        
      End If
      
    End If

  End Sub
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewCommandEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewCommandEventArgs Example</h3>
                       
      <asp:formview id="ProductFormView"
        datasourceid="ProductSource"
        allowpaging="true"
        datakeynames="ProductID"
        onitemcommand="ProductFormView_ItemCommand"
        ondatabound="ProductFormView_DataBound"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td style="width:400px">
                <b>Description:</b>
                <asp:label id="ProductNameLabel"
                  text='<%# Eval("ProductName") %>'
                  runat='server'/>
                <br/>      
                <b>Price:</b>
                <asp:label id="PriceLabel"
                  text='<%# Eval("UnitPrice", "{0:c}") %>'
                  runat='server'/>
                <br/>  
                <asp:textbox id="QuantityTextBox"
                  width="50px"
                  maxlength="3" 
                  runat="server"/> Qty                   
              </td>
            </tr>
            <tr>
              <td>
                <asp:requiredfieldvalidator ID="QuantityRequiredValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter a quantity."
                  display="Static"
                  runat="server"/>
                <br/>
                <asp:CompareValidator id="QuantityCompareValidator"
                  controltovalidate="QuantityTextBox"
                  text="Please enter an integer value."
                  display="Static"
                  type="Integer"
                  operator="DataTypeCheck"  
                  runat="server"/>    
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="AddButton"
                  text="Add"
                  commandname="Add"
                  runat="server"/>
              </td>
            </tr>
          </table>
        
        </itemtemplate>
                  
      </asp:formview>
      
      <br/><br/><hr/>
      
      Items:<br/>
      <asp:listbox id="ProductListBox"
        runat="server"/>
          
      <!-- 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="ProductSource"
        selectcommand="Select [ProductID], [ProductName], [UnitPrice] From [Products]"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

Remarques

Utilisez la CommandSource propriété pour accéder aux propriétés du contrôle qui a déclenché l’événement. Dans le cas d’un FormViewCommandEventArgs objet, le contrôle est le bouton sur lequel l’utilisateur a cliqué.

S’applique à

Voir aussi