FormViewDeleteEventArgs.Keys Propriedade

Definição

Obtém um dicionário ordenado de pares nome-valor do campo de chave do registro a ser excluído.Gets an ordered dictionary of key field name/value pairs for the record to delete.

public:
 property System::Collections::Specialized::IOrderedDictionary ^ Keys { System::Collections::Specialized::IOrderedDictionary ^ get(); };
public System.Collections.Specialized.IOrderedDictionary Keys { get; }
member this.Keys : System.Collections.Specialized.IOrderedDictionary
Public ReadOnly Property Keys As IOrderedDictionary

Valor da propriedade

IOrderedDictionary

Um OrderedDictionary que contém os pares de nome/valor do campo de chave para o registro a ser excluído.An OrderedDictionary that contains the key field name/value pairs for the record to delete.

Exemplos

O exemplo a seguir demonstra como usar a Keys propriedade para acessar o valor do campo de chave para o registro que está sendo excluído.The following example demonstrates how to use the Keys property to access the value of the key field for the record being deleted.


<%@ 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 EmployeeFormView_ItemDeleting(Object sender, FormViewDeleteEventArgs e)
  {
    // Get the employee ID, name, and job title from the Keys and Values
    // properties.
    String keyValue = e.Keys["EmployeeID"].ToString();
    String employeeName = e.Values["FirstName"].ToString() +
      " " + e.Values["LastName"].ToString();
    String title = e.Values["Title"].ToString();

    // Cancel the delete operation if the user attempts to 
    // delete a protected record. In this example, records for
    // employees with a "Sales Manager" job title are protected.
    if (title.Equals("Sales Manager"))
    {
      e.Cancel = true;
      MessageLabel.Text = "You cannot delete record " +
        e.RowIndex.ToString() + ". " + employeeName +
        " (Employee Number " + keyValue.ToString() +
        ") is protected.";
    }

  }
   
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewDeleteEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewDeleteEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        onitemdeleting="EmployeeFormView_ItemDeleting"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td>
                <asp:image id="EmployeeImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  runat="server"/>
              </td>
              <td>
                <asp:label id="FirstNameLabel"
                  text='<%#Bind("FirstName")%>'
                  font-bold="true"
                  runat="server"/>
                <asp:label id="LastNameLabel"
                  text='<%#Bind("LastName")%>'
                  font-bold="true"
                  runat="server"/>
                <br/>     
                <asp:label id="TitleLabel"
                  text='<%#Bind("Title")%>'
                  runat="server"/>        
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="DeleteButton"
                  text="Delete Record"
                  commandname="Delete"
                  runat="server" />
              </td>
            </tr>
          </table>
        
        </itemtemplate>         
                  
      </asp:formview>
      
      <asp:label id="MessageLabel"
        forecolor="Red"
        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="EmployeeSource"
        selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
        deletecommand="Delete [Employees] Where [EmployeeID]=@EmployeeID"
        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 EmployeeFormView_ItemDeleting(ByVal sender As Object, ByVal e As FormViewDeleteEventArgs)
  
    ' Get the employee ID, name, and job title from the Keys and Values
    ' properties.
    Dim keyValue As String = e.Keys("EmployeeID").ToString()
    Dim employeeName As String = e.Values("FirstName").ToString() & _
      " " & e.Values("LastName").ToString()
    Dim title As String = e.Values("Title").ToString()

    ' Cancel the delete operation if the user attempts to 
    ' delete a protected record. In this example, records for
    ' employees with a "Sales Manager" job title are protected.
    If Title.Equals("Sales Manager") Then
    
      e.Cancel = True
      MessageLabel.Text = "You cannot delete record " & _
        e.RowIndex.ToString() & ". " & employeeName & _
        " (Employee Number " & keyValue.ToString() & _
        ") is protected."
    
    End If

  End Sub
   
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewDeleteEventArgs Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewDeleteEventArgs Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        onitemdeleting="EmployeeFormView_ItemDeleting"  
        runat="server">
        
        <itemtemplate>
        
          <table>
            <tr>
              <td>
                <asp:image id="EmployeeImage"
                  imageurl='<%# Eval("PhotoPath") %>'
                  alternatetext='<%# Eval("LastName") %>' 
                  runat="server"/>
              </td>
              <td>
                <asp:label id="FirstNameLabel"
                  text='<%#Bind("FirstName")%>'
                  font-bold="true"
                  runat="server"/>
                <asp:label id="LastNameLabel"
                  text='<%#Bind("LastName")%>'
                  font-bold="true"
                  runat="server"/>
                <br/>     
                <asp:label id="TitleLabel"
                  text='<%#Bind("Title")%>'
                  runat="server"/>        
              </td>
            </tr>
            <tr>
              <td colspan="2">
                <asp:button id="DeleteButton"
                  text="Delete Record"
                  commandname="Delete"
                  runat="server" />
              </td>
            </tr>
          </table>
        
        </itemtemplate>         
                  
      </asp:formview>
      
      <asp:label id="MessageLabel"
        forecolor="Red"
        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="EmployeeSource"
        selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
        deletecommand="Delete [Employees] Where [EmployeeID]=@EmployeeID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>" 
        runat="server"/>
            
    </form>
  </body>
</html>

Comentários

A Keys propriedade contém os valores dos campos de chave listados na DataKeyNames propriedade de um FormView controle.The Keys property contains the values of the key fields listed in the DataKeyNames property of a FormView control. Use a Keys propriedade para acessar os valores do campo de chave ou campos para o registro a ser excluído.Use the Keys property to access the values of the key field or fields for the record to be deleted. Por exemplo, você pode usar esses valores para verificar o registro antes de excluí-lo, alterar o registro a ser excluído ou manter um log dos registros excluídos.For example, you can use these values to verify the record before deleting it, to change the record to delete, or to keep a log of deleted records.

Observação

Essa propriedade contém apenas os campos de chave.This property contains only the key fields. Para acessar os valores de pares nome/valor dos campos não chave, use a Values propriedade.To access the name/value pair values for the non-key fields, use the Values property.

A Keys propriedade retorna um OrderedDictionary objeto que implementa a System.Collections.Specialized.IOrderedDictionary interface.The Keys property returns an OrderedDictionary object that implements the System.Collections.Specialized.IOrderedDictionary interface. O OrderedDictionary objeto contém System.Collections.DictionaryEntry objetos que representam os campos de chave.The OrderedDictionary object contains System.Collections.DictionaryEntry objects that represent the key fields. Para acessar os nomes de campo de chave, use a Keys Propriedade do OrderedDictionary objeto.To access the key field names, use the Keys property of the OrderedDictionary object. Da mesma forma, você pode acessar os valores de campo de chave usando a Values propriedade.Similarly, you can access the key field values by using the Values property.

Observação

Como um atalho, você também pode usar o indexador do OrderedDictionary objeto para acessar os valores de campo de chave.As a shortcut, you can also use the indexer of the OrderedDictionary object to access the key field values. A vantagem de usar o indexador é que ele retorna valores de campo de chave diretamente.The advantage in using the indexer is that it returns key field values directly. Os controles da fonte de dados que dependem da ordem do campo (como AccessDataSource ) podem acessar valores de campo de chave somente por índice.Data source controls that rely on the field order (such as AccessDataSource) can access key field values only by index.

As Keys Values Propriedades e são somente leitura; no entanto, você pode modificar os valores de campo do OrderedDictionary objeto.The Keys and Values properties are read-only; however, you can modify the field values of the OrderedDictionary object. Se você alterar os valores de campo de chave e não chave, o registro correspondente será excluído da fonte de dados.If you change the key and non-key field values, the corresponding record will be deleted from the data source.

Aplica-se a

Confira também