GridViewUpdatedEventArgs.AffectedRows Eigenschaft
Definition
Wichtig
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Ruft die Anzahl der vom Aktualisierungsvorgang betroffenen Zeilen ab.
public:
property int AffectedRows { int get(); };public int AffectedRows { get; }member this.AffectedRows : intPublic ReadOnly Property AffectedRows As IntegerEigenschaftswert
Die Anzahl der vom Aktualisierungsvorgang betroffenen Zeilen.
Beispiele
Im folgenden Beispiel wird gezeigt, wie Sie die AffectedRows Eigenschaft verwenden, um zu überprüfen, ob ein Datensatz aktualisiert wurde.
<%@ 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 CustomersGridView_RowUpdated(Object sender, GridViewUpdatedEventArgs e)
{
// Use the Exception property to determine whether an exception
// occurred during the update operation.
if (e.Exception == null)
{
// Sometimes an error might occur that does not raise an
// exception, but prevents the update operation from
// completing. Use the AffectedRows property to determine
// whether the record was actually updated.
if (e.AffectedRows == 1)
{
// Use the Keys property to get the value of the key field.
String keyFieldValue = e.Keys["CustomerID"].ToString();
// Display a confirmation message.
Message.Text = "Record " + keyFieldValue +
" updated successfully. ";
// Display the new and original values.
DisplayValues((OrderedDictionary)e.NewValues, (OrderedDictionary)e.OldValues);
}
else
{
// Display an error message.
Message.Text = "An error occurred during the update operation.";
// When an error occurs, keep the GridView
// control in edit mode.
e.KeepInEditMode = true;
}
}
else
{
// Insert the code to handle the exception.
Message.Text = e.Exception.Message;
// Use the ExceptionHandled property to indicate that the
// exception is already handled.
e.ExceptionHandled = true;
e.KeepInEditMode = true;
}
}
void DisplayValues(OrderedDictionary newValues, OrderedDictionary oldValues)
{
Message.Text += "<br/></br>";
// Iterate through the new and old values. Display the
// values on the page.
for (int i = 0; i < oldValues.Count; i++)
{
Message.Text += "Old Value=" + oldValues[i].ToString() +
", New Value=" + newValues[i].ToString() + "<br/>";
}
Message.Text += "</br>";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewUpdatedEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewUpdatedEventArgs Example</h3>
<!-- The GridView control automatically sets the columns -->
<!-- specified in the datakeynames property as read-only. -->
<!-- No input controls are rendered for these columns in -->
<!-- edit mode. -->
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSqlDataSource"
autogeneratecolumns="true"
autogenerateeditbutton="true"
allowpaging="true"
datakeynames="CustomerID"
onrowupdated="CustomersGridView_RowUpdated"
runat="server">
</asp:gridview>
<br/>
<asp:label id="Message"
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="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server">
</asp:sqldatasource>
</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 CustomersGridView_RowUpdated(sender As Object, e As GridViewUpdatedEventArgs)
' Use the Exception property to determine whether an exception
' occurred during the update operation.
If e.Exception Is Nothing Then
' Sometimes an error might occur that does not raise an
' exception, but prevents the update operation from
' completing. Use the AffectedRows property to determine
' whether the record was actually updated.
If e.AffectedRows = 1 Then
' Use the Keys property to get the value of the key field.
Dim keyFieldValue As String = e.Keys("CustomerID").ToString()
' Display a confirmation message.
Message.Text = "Record " & keyFieldValue & _
" updated successfully. "
' Display the new and original values.
DisplayValues(CType(e.NewValues, OrderedDictionary), CType(e.OldValues, OrderedDictionary))
Else
' Display an error message.
Message.Text = "An error occurred during the update operation."
' When an error occurs, keep the GridView
' control in edit mode.
e.KeepInEditMode = True
End If
Else
' Insert the code to handle the exception.
Message.Text = e.Exception.Message
' Use the ExceptionHandled property to indicate that the
' exception is already handled.
e.ExceptionHandled = True
e.KeepInEditMode = True
End If
End Sub
Sub DisplayValues(ByVal newValues As OrderedDictionary, ByVal oldValues As OrderedDictionary)
Message.Text &= "<br/></br>"
' Iterate through the new and old values. Display the
' values on the page.
Dim i As Integer
For i = 0 To oldValues.Count - 1
Message.Text &= "Old Value=" & oldValues(i).ToString() & _
", New Value=" & newValues(i).ToString() & "<br/>"
Next
Message.Text &= "</br>"
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>GridViewUpdatedEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>GridViewUpdatedEventArgs Example</h3>
<!-- The GridView control automatically sets the columns -->
<!-- specified in the datakeynames property as read-only. -->
<!-- No input controls are rendered for these columns in -->
<!-- edit mode. -->
<asp:gridview id="CustomersGridView"
datasourceid="CustomersSqlDataSource"
autogeneratecolumns="true"
autogenerateeditbutton="true"
allowpaging="true"
datakeynames="CustomerID"
onrowupdated="CustomersGridView_RowUpdated"
runat="server">
</asp:gridview>
<br/>
<asp:label id="Message"
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="CustomersSqlDataSource"
selectcommand="Select [CustomerID], [CompanyName], [Address], [City], [PostalCode], [Country] From [Customers]"
updatecommand="Update Customers SET CompanyName=@CompanyName, Address=@Address, City=@City, PostalCode=@PostalCode, Country=@Country WHERE (CustomerID = @CustomerID)"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server">
</asp:sqldatasource>
</form>
</body>
</html>
Hinweise
Da in der Regel nur ein Datensatz aktualisiert wird, enthält diese Eigenschaft in der Regel einen Wert von 0 oder 1.
Ein Fehler kann während des Updatevorgangs auftreten, der keine Ausnahme auslöst. Sie können die AffectedRows Eigenschaft verwenden, um sicherzustellen, dass ein Datensatz aktualisiert wurde.