GridViewDeleteEventArgs.Keys Vlastnost

Definice

Získá slovník párů název pole/hodnota, který představuje primární klíč řádku, který se má odstranit.Gets a dictionary of field name/value pairs that represent the primary key of the row 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

Hodnota vlastnosti

IOrderedDictionary

Slovník obsahující páry název/hodnota pole, které reprezentují primární klíč řádku, který má být odstraněn.A dictionary that contains field name/value pairs that represent the primary key of the row to delete.

Příklady

Následující příklad ukazuje, jak použít Values vlastnost k získání hodnot klíčových polí pro řádek, který se má odstranit.The following example shows how to use the Values property to get the values of the key fields for the row to delete. Hodnoty se pak zapíší do souboru protokolu odstraněných záznamů.The values are then written to a log file of deleted records.


<%@ Page language="C#" %>
<%@ import namespace="System.IO" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  void CustomersGridView_RowDeleting(Object sender, GridViewDeleteEventArgs e)
  {

    // Record the delete operation in a log file.

    // Create the log text. 
    String logText = "";

    // Append the values of the key fields to the log text.
    foreach (DictionaryEntry keyEntry in e.Keys)
    {
      logText += keyEntry.Key + "=" + keyEntry.Value + ";";
    }

    // Append the values of the non-key fields to the log text.
    foreach (DictionaryEntry valueEntry in e.Values)
    {
      logText += valueEntry.Key + "=" + valueEntry.Value + ";";
    }

    // Display the log content.
    LogTextLabel.Text = logText;
    
    // Append the text to a log file.
    try
    {
      StreamWriter sw;
      sw = File.AppendText(Server.MapPath(null) + "\\deletelog.txt");
      sw.WriteLine(logText);
      sw.Flush();
      sw.Close();
    }
    catch(UnauthorizedAccessException ex)
    {
      // You must provide read/write access to the file using ACLs.
      LogErrorLabel.Text = "You do not have permission to write to the log.";
    }

  }
    
  void CustomersGridView_RowDeleted(Object sender, GridViewDeletedEventArgs e)
  {
    
    if (e.Exception == null)
    {
      // The delete operation succeeded. Clear the message label.
      Message.Text = "";
    }
    else
    {
      // The delete operation failed. Display an error message.
      Message.Text = e.AffectedRows.ToString() + " rows deleted. " + e.Exception.Message;
      e.ExceptionHandled = true;
    }
        
  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridViewDeleteEventArgs Keys and Values Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridViewDeleteEventArgs Keys and Values Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"          
        runat="server"/>
        
      <br/>
      
      <asp:label id="LogTextLabel"
        forecolor="Red"          
        runat="server"/>
        
      <br/>
        
      <asp:label id="LogErrorLabel"
        forecolor="Red"          
        runat="server"/>
                
      <br/>

      <asp:gridview id="CustomersGridView" 
        allowpaging="true"
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="true"
        autogeneratedeletebutton="true" 
        datakeynames="CustomerID"
        onrowdeleted="CustomersGridView_RowDeleted"
        onrowdeleting="CustomersGridView_RowDeleting"   
        runat="server">
        
      </asp:gridview>
            
      <!-- 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="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        deletecommand="Delete from Customers where CustomerID = @CustomerID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
            
    </form>
  </body>
</html>


<%@ Page language="VB" %>
<%@ import namespace="System.IO" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

  Sub CustomersGridView_RowDeleting(ByVal sender As Object, ByVal e As GridViewDeleteEventArgs)

    ' Record the delete operation in a log file.

    ' Create the log text. 
    Dim logText As String = ""

    ' Append the values of the key fields to the log text.
    Dim i As Integer
    For i = 0 To e.Keys.Count - 1
    
      logText &= e.Keys(i).ToString() & ";"
      
    Next

    ' Append the values of the non-key fields to the log text.
    For i = 0 To e.Values.Count - 1
    
      If e.Values(i) IsNot Nothing Then
        logText &= e.Values(i).ToString() & ";"
      Else
        logText &= "Nothing" & ";"
      End If
      
    Next
    
    ' Display the log content.
    LogTextLabel.Text = logText

    ' Append the text to a log file.
    Try
    
      Dim sw As StreamWriter
      sw = File.AppendText(Server.MapPath(Nothing) & "\deletelog.txt")
      sw.WriteLine(logText)
      sw.Flush()
      sw.Close()
    
    Catch ex As UnauthorizedAccessException
    
      ' You must provide read/write access to the file using ACLs.
      LogErrorLabel.Text = "You do not have permission to write to the log."
    
    End Try

  End Sub
    
  Sub CustomersGridView_RowDeleted(ByVal sender As Object, ByVal e As GridViewDeletedEventArgs)
    
    If e.Exception Is Nothing Then
    
      ' The delete operation succeeded. Clear the message label.
      Message.Text = ""
    
    Else
    
      ' The delete operation failed. Display an error message.
      Message.Text = e.AffectedRows.ToString() & " rows deleted. " & e.Exception.Message
      e.ExceptionHandled = True
      
    End If
        
  End Sub

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridViewDeleteEventArgs Keys and Values Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridViewDeleteEventArgs Keys and Values Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"          
        runat="server"/>
        
      <br/>
      
      <asp:label id="LogTextLabel"
        forecolor="Red"          
        runat="server"/>
        
      <br/>
        
      <asp:label id="LogErrorLabel"
        forecolor="Red"          
        runat="server"/>
                
      <br/>

      <asp:gridview id="CustomersGridView" 
        allowpaging="true"
        datasourceid="CustomersSqlDataSource" 
        autogeneratecolumns="true"
        autogeneratedeletebutton="true" 
        datakeynames="CustomerID"
        onrowdeleted="CustomersGridView_RowDeleted"
        onrowdeleting="CustomersGridView_RowDeleting"   
        runat="server">
        
      </asp:gridview>
            
      <!-- 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="CustomersSqlDataSource"  
        selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
        deletecommand="Delete from Customers where CustomerID = @CustomerID"
        connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
        runat="server">
      </asp:sqldatasource>
            
    </form>
  </body>
</html>

Poznámky

Když DataKeyNames GridView je nastavena vlastnost ovládacího prvku, použijte Keys vlastnost (Dictionary) k získání hodnoty primárního klíče nebo klíčů řádku, který se má odstranit.When the DataKeyNames property of a GridView control is set, use the Keys property (dictionary) to get the value of the primary key or keys of the row to delete.

Poznámka

Chcete-li získat hodnoty polí, která nejsou klíčová, použijte Values vlastnost.To get the values of the non-key fields, use the Values property.

KeysSlovník se automaticky vyplní páry název-hodnota pole nebo polí určených ve DataKeyNames Vlastnosti.The Keys dictionary is automatically populated with the name/value pairs of the field or fields specified in the DataKeyNames property. Pokud bude primární klíč tvořit více polí, do Keys slovníku pro každé pole klíče se přidá samostatná položka.If multiple fields form the primary key, a separate entry is added to the Keys dictionary for each key field.

Chcete-li určit název klíčového pole, použijte DictionaryEntry.Key vlastnost System.Collections.DictionaryEntry objektu ve Keys slovníku.To determine the name of a key field, use the DictionaryEntry.Key property of a System.Collections.DictionaryEntry object in the Keys dictionary. K určení hodnoty klíčového pole použijte DictionaryEntry.Value vlastnost.To determine the value of a key field, use the DictionaryEntry.Value property.

Platí pro

Viz také