FormViewDeletedEventArgs.Keys FormViewDeletedEventArgs.Keys FormViewDeletedEventArgs.Keys FormViewDeletedEventArgs.Keys Property

Определение

Возвращает упорядоченный словарь, содержащий пары "имя/значение" для ключевых полей удаленной записи.Gets an ordered dictionary of key field name/value pairs for the deleted record.

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

Значение свойства

Словарь OrderedDictionary, содержащий пары "имя-значение" для ключевых полей удаленной записи.An OrderedDictionary that contains key field name/value pairs for the deleted record.

Примеры

В следующем примере показано, как использовать Keys свойство для доступа к значениям ключевых полей удаленной записи.The following example demonstrates how to use the Keys property to access the values of the key fields for a deleted record.


<%@ 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_ItemDeleted(Object sender, FormViewDeletedEventArgs e)
  {
    // Display the values of the key fields in the Keys property.
    KeysMessageLabel.Text =
      "The key fields for the deleted record are: <br/>";

    foreach (DictionaryEntry entry in e.Keys)
    {
      DisplayValue(entry, KeysMessageLabel);
    }

    // Display the values of the non-key fields in the Values 
    // property.
    ValuesMessageLabel.Text =
      "The non-key fields for the deleted record are: <br/>";

    foreach (DictionaryEntry entry in e.Values)
    {
      DisplayValue(entry, ValuesMessageLabel);
    }

  }

  void DisplayValue(DictionaryEntry entry, Label displayLabel)
  {
    // Display the field name contained in the DictionaryEntry object.
    if (entry.Key != null)
    {
      displayLabel.Text += "Name=" + entry.Key.ToString() + ", ";
    }
    else
    {
      displayLabel.Text += "Name=null, ";
    }

    // Display the field value contained in the DictionaryEntry object.
    if (entry.Value != null)
    {
      displayLabel.Text += "Value=" + entry.Value.ToString() + "<br/>";
    }
    else
    {
      displayLabel.Text += "Value=null<br/>";
    }
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewDeletedEventArgs Keys and Values Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewDeletedEventArgs Keys and Values Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        onitemdeleted="EmployeeFormView_ItemDeleted"  
        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="KeysMessageLabel"
        forecolor="Red"
        runat="server"/>
          
      <br/><br/>
          
      <asp:label id="ValuesMessageLabel"
        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_ItemDeleted(ByVal sender As Object, ByVal e As FormViewDeletedEventArgs) Handles EmployeeFormView.ItemDeleted
  
    Dim entry As DictionaryEntry
    
    ' Display the values of the key fields in the Keys property.
    KeysMessageLabel.Text = _
      "The key fields for the deleted record are: <br/>"

    ' In Visual Basic, you cannot iterate through the DictionaryEntry objects
    ' in the Keys property directly. Use the CopyTo method to 
    ' copy the objects to an array first.
    Dim keysArray(e.Keys.Count - 1) As DictionaryEntry
    e.Keys.CopyTo(keysArray, 0)
    
    ' Iterate through the array and display its values.
    For Each entry In keysArray
    
      DisplayValue(entry, KeysMessageLabel)
    
    Next

    ' Display the values of the non-key fields in the Values 
    ' property.
    ValuesMessageLabel.Text = _
      "The non-key fields for the deleted record are: <br/>"

    Dim valuesArray(e.Values.Count - 1) As DictionaryEntry
    e.Values.CopyTo(valuesArray, 0)

    For Each entry In valuesArray
    
      DisplayValue(entry, ValuesMessageLabel)
    
    Next

  End Sub

  Sub DisplayValue(ByVal entry As DictionaryEntry, ByVal displayLabel As Label)
  
    ' Display the field name contained in the DictionaryEntry object.
    If entry.Key IsNot Nothing Then
    
      displayLabel.Text &= "Name=" & entry.Key.ToString() & ", "
    
    Else
    
      displayLabel.Text &= "Name=null, "
      
    End If

    ' Display the field value contained in the DictionaryEntry object.
    If entry.Value IsNot Nothing Then
    
      displayLabel.Text &= "Value=" & entry.Value.ToString() & "<br/>"
    
    Else
    
      displayLabel.Text &= "Value=null<br/>"
      
    End If
        
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>FormViewDeletedEventArgs Keys and Values Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>FormViewDeletedEventArgs Keys and Values Example</h3>
                       
      <asp:formview id="EmployeeFormView"
        datasourceid="EmployeeSource"
        allowpaging="true"
        datakeynames="EmployeeID"
        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="KeysMessageLabel"
        forecolor="Red"
        runat="server"/>
          
      <br/><br/>
          
      <asp:label id="ValuesMessageLabel"
        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>

Комментарии

Свойство содержит значения ключевых полей, перечисленных DataKeyNames в свойстве FormView элемента управления. KeysThe Keys property contains the values of the key fields listed in the DataKeyNames property of a FormView control. Используйте свойство для доступа к значениям ключевых полей (как указано в DataKeyNames свойстве) для удаленной записи. KeysUse the Keys property to access the values of the key fields (as specified by the DataKeyNames property) for a deleted record. Например, эти значения можно использовать для сохранения журнала удаленных записей.For example, you can use these values to keep a log of deleted records.

Примечание

Это свойство содержит только ключевые поля, DataKeyNames указанные в свойстве.This property contains only the key fields specified in the DataKeyNames property. Для доступа к неключевым полям используйте Values свойство.To access the non-key fields, use the Values property.

Свойство возвращает объект, реализующий System.Collections.Specialized.IOrderedDictionaryинтерфейс. Keys OrderedDictionaryThe Keys property returns an OrderedDictionary object that implements the System.Collections.Specialized.IOrderedDictionary interface. OrderedDictionary Объект содержитSystem.Collections.DictionaryEntry объекты, представляющие ключевые поля удаленной записи.The OrderedDictionary object contains System.Collections.DictionaryEntry objects that represent the key fields of the deleted record. Чтобы получить доступ к именам полей, Keys используйте свойство OrderedDictionary объекта.To access the field names, use the Keys property of the OrderedDictionary object. Аналогичным образом можно получить доступ к значениям полей с Values помощью свойства.Similarly, you can access the field values by using the Values property.

Примечание

Для доступа к значениям ключевого поля можно также использовать индексатор OrderedDictionary объекта в качестве ярлыка.As a shortcut, you can also use the indexer of the OrderedDictionary object to access the key field values. Преимущество использования индексатора заключается в том, что он возвращает значения ключевых полей напрямую.The advantage in using the indexer is that it returns key field values directly. Элементы управления источниками данных, зависящие от порядка полей ( AccessDataSourceнапример,), могут получать доступ к значениям полей ключей только по индексу.Data source controls that rely on the field order (such as AccessDataSource) can access key field values only by index.

Применяется к

Дополнительно