SqlDataSourceCommandEventArgs Class
Assembly: System.Web (in system.web.dll)
By adding an event handler delegate to handle the Updating, Inserting, or Deleting events, you can perform any additional preprocessing required or cancel the database command entirely.
Because the SqlDataSourceCommandEventArgs class is derived from the CancelEventArgs class, you can cancel a pending SqlDataSource database command by setting the Cancel property to true. You can examine and manipulate the CommandText, Parameters collection, and other command properties prior to running the command by accessing the DbCommand object exposed by the Command property.
The SqlDataSourceCommandEventArgs class is used in the OnUpdating, OnInserting, and OnDeleting methods to provide access to a SqlDataSource database command before it is run. The SqlDataSource control exposes many events that you can handle to work with the underlying data objects during the course of a data operation. The following table lists the events and associated EventArgs and event handler classes, to better guide you to the various events that correspond to the lifecycle of a data operation using the SqlDataSource control.
| Event | EventArgs | EventHandler |
|---|---|---|
| Selecting occurs before the data is retrieved. | ||
| Inserting, Updating, Deleting occur before an insert, update, or delete operation is performed. | SqlDataSourceCommandEventArgs | |
| Selected, Inserted, Updated, Deleted occur after the data retrieval, insert, update, or delete operations completes. |
The following code example demonstrates how to display data retrieved from a Microsoft SQL Server database in a DropDownList control, and update the record using a TextBox control. The example shows how you can use a DbTransaction object to add transaction context when using the SqlDataSource control to update data.
<%@Page Language="VJ#" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@Import Namespace="System.Diagnostics" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
private void On_Click(Object source, System.EventArgs e)
{
try {
SqlDataSource1.Update();
}
catch (System.Exception except) {
// Handle Exception
}
Label2.set_Text("The record was updated successfully!");
} //On_Click
private void OnSqlUpdate(Object source, SqlDataSourceCommandEventArgs e)
{
// Log the command in the Event Log on the Web server.
String logInfo = e.get_Command().get_CommandText()
+ " is being submitted to the database.";
IEnumerator ie = e.get_Command().get_Parameters().GetEnumerator();
while (ie.MoveNext()) {
DbParameter param = ((DbParameter)(ie.get_Current()));
logInfo = logInfo + " " + param.get_ParameterName()+ "="
+ param.get_Value();
}
EventLog log = new EventLog();
log.set_Log("Application");
log.set_Source("ASP.NET Example");
log.WriteEntry(logInfo);
} //OnSqlUpdate
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>ASP.NET Example</title>
</head>
<body>
<form id="form1" runat="server">
<asp:SqlDataSource
id="SqlDataSource1"
runat="server"
ConnectionString="Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;"
SelectCommand="SELECT EmployeeID, LastName, Address FROM Employees"
UpdateCommand="UPDATE Employees SET Address=@Address WHERE EmployeeID=@EmployeeID"
OnUpdating="OnSqlUpdate">
<UpdateParameters>
<asp:ControlParameter Name="Address" ControlId="TextBox1" PropertyName="Text"/>
<asp:ControlParameter Name="EmployeeID" ControlId="DropDownList1" PropertyName="SelectedValue"/>
</UpdateParameters>
</asp:SqlDataSource>
<asp:DropDownList
id="DropDownList1"
runat="server"
DataTextField="LastName"
DataValueField="EmployeeID"
DataSourceID="SqlDataSource1">
</asp:DropDownList>
<br />
<asp:Label id="Label1" runat="server" Text="Enter a new address for the selected user."
AssociatedControlID="TextBox1" />
<asp:TextBox id="TextBox1" runat="server" />
<asp:Button id="Submit" runat="server" Text="Submit" OnClick="On_Click" />
<br /><asp:Label id="Label2" runat="server" Text="" />
</form>
</body>
</html>
- AspNetHostingPermission for operating in a hosted environment. Demand value: LinkDemand; Permission value: Minimal.
- AspNetHostingPermission for operating in a hosted environment. Demand value: InheritanceDemand; Permission value: Minimal.
System.EventArgs
System.ComponentModel.CancelEventArgs
System.Web.UI.WebControls.SqlDataSourceCommandEventArgs
System.Web.UI.WebControls.SqlDataSourceSelectingEventArgs