GridViewDeleteEventArgs.Keys Propriedade
Definição
Importante
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Obtém um dicionário de pares nome/valor de campo que representam a chave primária da linha a ser excluída.
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.IOrderedDictionaryPublic ReadOnly Property Keys As IOrderedDictionaryValor da propriedade
Um dicionário que contém pares nome/valor de campo que representam a chave primária da linha a ser excluída.
Exemplos
O exemplo a seguir mostra como usar a Values propriedade para obter os valores dos campos de chave para a linha a ser excluída. Os valores são gravados em um arquivo de log de registros excluídos.
<%@ 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>
Comentários
Quando a DataKeyNames propriedade de um GridView controle for definida, use a Keys propriedade (dicionário) para obter o valor da chave primária ou das chaves da linha a ser excluída.
Observação
Para obter os valores dos campos não chave, use a Values propriedade.
O Keys dicionário é preenchido automaticamente com os pares nome/valor do campo ou campos especificados na DataKeyNames propriedade. Se vários campos formarem a chave primária, uma entrada separada será adicionada ao Keys dicionário para cada campo de chave.
Para determinar o nome de um campo de chave, use a DictionaryEntry.Key propriedade de um System.Collections.DictionaryEntry objeto no Keys dicionário. Para determinar o valor de um campo de chave, use a DictionaryEntry.Value propriedade.