Επεξεργασία

Κοινή χρήση μέσω


SqlDataSourceCommandEventArgs Class

Definition

Provides data for the Updating, Deleting and Inserting events of the SqlDataSource control.

public ref class SqlDataSourceCommandEventArgs : System::ComponentModel::CancelEventArgs
public class SqlDataSourceCommandEventArgs : System.ComponentModel.CancelEventArgs
type SqlDataSourceCommandEventArgs = class
    inherit CancelEventArgs
Public Class SqlDataSourceCommandEventArgs
Inherits CancelEventArgs
Inheritance
SqlDataSourceCommandEventArgs
Derived

Examples

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="C#" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@Import Namespace="System.Data.SqlClient" %>
<%@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, EventArgs e) {    
    SqlDataSource1.Update();
 }

 private void OnSqlUpdating(Object source, SqlDataSourceCommandEventArgs e) {
    DbCommand command = e.Command;
    DbConnection cx  = command.Connection;    
    cx.Open();    
    DbTransaction tx = cx.BeginTransaction();
    command.Transaction = tx;
 }

 private void OnSqlUpdated(Object source, SqlDataSourceStatusEventArgs e) {
    DbCommand command = e.Command;
    DbTransaction tx = command.Transaction;
    
    // In this code example the OtherProcessSucceeded variable represents
    // the outcome of some other process that occurs whenever the data is 
    // updated, and must succeed for the data change to be committed. For 
    // simplicity, we set this value to true. 
    bool OtherProcessSucceeded = true;
    
    if (OtherProcessSucceeded) {
        tx.Commit();
        Label2.Text="The record was updated successfully!";
    }
    else {
        tx.Rollback();
        Label2.Text="The record was not updated.";
    }
 }

</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="<%$ ConnectionStrings:MyNorthwind%>"
          SelectCommand="SELECT EmployeeID, LastName, Address FROM Employees"
          UpdateCommand="UPDATE Employees SET Address=@Address WHERE EmployeeID=@EmployeeID"
          OnUpdating="OnSqlUpdating"
          OnUpdated ="OnSqlUpdated">
          <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>
<%@Page  Language="VB" %>
<%@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">

 Sub On_Click(ByVal source As Object, ByVal e As EventArgs)
        SqlDataSource1.Update()
 End Sub 'On_Click

 Sub On_Sql_Updating(ByVal source As Object, ByVal e As SqlDataSourceCommandEventArgs)
     Dim command as DbCommand
     Dim connection as DbConnection
     Dim transaction as DbTransaction
     
     command    = e.Command
     connection = command.Connection     
     connection.Open()     
     transaction = connection.BeginTransaction()
     command.Transaction = transaction
 
 End Sub 'On_Sql_Updating
 
 Sub On_Sql_Updated(ByVal source As Object, ByVal e As SqlDataSourceStatusEventArgs)
 
    Dim command As DbCommand
    Dim transaction As DbTransaction
    
    command = e.Command
    transaction = command.Transaction
    
    ' In this code example the OtherProcessSucceeded variable represents
    ' the outcome of some other process that occurs whenever the data is 
    ' updated, and must succeed for the data change to be committed. For 
    ' simplicity, we set this value to true. 
    Dim OtherProcessSucceeded as Boolean = True
    
    If (OtherProcessSucceeded) Then
        transaction.Commit()
        Label2.Text="The record was updated successfully!"
    Else    
        transaction.Rollback()
        Label2.Text="The record was not updated."
    End If
 End Sub ' On_Sql_Updated
</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="<%$ ConnectionStrings:MyNorthwind%>"
          SelectCommand="SELECT EmployeeID, LastName, Address FROM Employees"
          UpdateCommand="UPDATE Employees SET Address=@Address WHERE EmployeeID=@EmployeeID"
          OnUpdating="On_Sql_Updating"
          OnUpdated ="On_Sql_Updated">
          <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>

Remarks

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. SqlDataSourceSelectingEventArgs SqlDataSourceSelectingEventHandler
Inserting, Updating, Deleting occur before an insert, update, or delete operation is performed. SqlDataSourceCommandEventArgs SqlDataSourceCommandEventHandler
Selected, Inserted, Updated, Deleted occur after the data retrieval, insert, update, or delete operations completes. SqlDataSourceStatusEventArgs SqlDataSourceStatusEventHandler

Constructors

SqlDataSourceCommandEventArgs(DbCommand)

Initializes a new instance of the SqlDataSourceCommandEventArgs class, using the specified database command object.

Properties

Cancel

Gets or sets a value indicating whether the event should be canceled.

(Inherited from CancelEventArgs)
Command

Gets the pending database command.

Methods

Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
ToString()

Returns a string that represents the current object.

(Inherited from Object)

Applies to

See also