SqlDataSourceCommandEventHandler Delegate

.NET Framework 2.0

Other Versions

Note: This delegate is new in the .NET Framework version 2.0.

Represents the method that will handle the Updating, Inserting, and Deleting events of the SqlDataSource control.

Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)

Syntax

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JScript

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'Declaration

Public Delegate Sub SqlDataSourceCommandEventHandler ( _
	sender As Object, _
	e As SqlDataSourceCommandEventArgs _
)

'Usage

Dim instance As New SqlDataSourceCommandEventHandler(AddressOf HandlerMethod)

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/** @delegate */
public delegate void SqlDataSourceCommandEventHandler (
	Object sender, 
	SqlDataSourceCommandEventArgs e
)

Parameters

sender: The source of the event, the SqlDataSource control.

e: A SqlDataSourceCommandEventArgs that contains the event data.

Remarks

When you create a SqlDataSourceCommandEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Consuming Events.

Example

The following code example demonstrates how to handle the Inserting event to perform any preprocessing steps, such as adding a parameter to the DbCommand object contained by the SqlDataSourceCommandEventArgs to capture the value of an output parameter, before a database action is performed. In this example an insert is performed by a DetailsView control in a classic master-detail scenario, using a stored procedure. The value of the output parameter, which represents the primary key of the newly inserted row, is examined when the Inserted event is raised after the operation completes.

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<%@Page  Language="VB" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!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_Inserting(ByVal sender As Object, ByVal e As SqlDataSourceCommandEventArgs)

    Dim insertedKey As SqlParameter  
    insertedKey = New SqlParameter("@PK_New", SqlDbType.Int)
    insertedKey.Direction    = ParameterDirection.Output     
    
    e.Command.Parameters.Add(insertedKey)

 End Sub 'On_Inserting

 Sub On_Inserted(ByVal sender As Object, ByVal e As SqlDataSourceStatusEventArgs)
    Dim command As DbCommand 
    command = e.Command
    
    ' The label displays the primary key of the recently inserted row.
    Label1.Text = command.Parameters("@PK_New").Value.ToString()    
    
    ' Explicitly call DataBind to refresh the data
    ' and show the newly inserted row.
    GridView1.DataBind()
 End Sub 'On_Inserted

</SCRIPT>

<HTML>
  <BODY>
    <FORM runat="server">

      <asp:GridView
        id="GridView1"
        runat="server"
        AutoGenerateColumns="False"
        DataKeyNames="EmployeeID"        
        DataSourceID="SqlDataSource1">
        <columns>          
          <asp:BoundField HeaderText="First Name" DataField="FirstName" />
          <asp:BoundField HeaderText="Last Name" DataField="LastName" />
          <asp:BoundField HeaderText="Title" DataField="Title" />
          <asp:ButtonField ButtonType="Link" CommandName="Select" Text="Details..." />
        </columns>
      </asp:GridView>

      <asp:SqlDataSource
        id="SqlDataSource1"
        runat="server"
        ConnectionString="<%$ ConnectionStrings:MyNorthwind %>"
        SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees">
      </asp:SqlDataSource>

      <HR>

      <asp:DetailsView
        id="DetailsView1"
        runat="server"
        DataSourceID="SqlDataSource2"
        AutoGenerateRows="False"
        AutoGenerateInsertButton="True">
        <fields>
          <asp:BoundField HeaderText="First Name" DataField="FirstName" ReadOnly="False"/>
          <asp:BoundField HeaderText="Last Name" DataField="LastName" ReadOnly="False"/>
          <asp:TemplateField HeaderText="Title">
            <ItemTemplate>
              <asp:DropDownList
                id="TitleDropDownList"
                runat="server"
                selectedvalue="<%# Bind('Title') %>" >
                <asp:ListItem Selected>Sales Representative</asp:ListItem>
                <asp:ListItem>Sales Manager</asp:ListItem>
                <asp:ListItem>Vice President, Sales</asp:ListItem>
              </asp:DropDownList>
            </ItemTemplate>
          </asp:TemplateField>
          <asp:BoundField HeaderText="Notes" DataField="Notes" ReadOnly="False"/>
        </fields>
      </asp:DetailsView>


      <asp:SqlDataSource
        id="SqlDataSource2"
        runat="server"
        ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
        SelectCommand="SELECT * FROM Employees"
        InsertCommandType = "StoredProcedure"
        InsertCommand="sp_insertemployee"        
        OnInserting="On_Inserting"
        OnInserted ="On_Inserted"
        FilterExpression="EmployeeID={0}">
        <FilterParameters>
          <asp:ControlParameter Name="EmployeeID" ControlId="GridView1" PropertyName="SelectedValue" />
        </FilterParameters>
      </asp:SqlDataSource>

<!-- 
     -- An example sp_insertemployee stored procedure that returns
     -- the primary key of the row that was inserted in an OUT parameter.
     CREATE PROCEDURE sp_insertemployee 
        @FirstName nvarchar(10), 
        @LastName nvarchar(20) , 
        @Title nvarchar(30), 
        @Notes nvarchar(200), 
        @PK_New int OUTPUT
      AS
        INSERT INTO Employees(FirstName,LastName,Title,Notes)VALUES (@FirstName,@LastName,@Title,@Notes)
        SELECT @PK_New = @@IDENTITY
        RETURN (1)    
      GO
-->      

      <asp:Label 
        id="Label1"
        runat="server" />
      
    </FORM>
  </BODY>
</HTML>

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<%@Page  Language="VJ#" %>
<%@Import Namespace="System.Data" %>
<%@Import Namespace="System.Data.Common" %>
<%@Import Namespace="System.Data.SqlClient" %>
<!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_Inserting(Object sender, SqlDataSourceCommandEventArgs e)
    {
        // Add the Title parameter from the TemplatedField.
        // Cast the first Item of the DetailsView to a Table.
        Table tbl = (Table)DetailsView1.get_Controls().get_Item(0);

        // Get row two (the third row) from the rows collection.
        // This is the row that the DropDownList is in.
        TableRowCollection rows = tbl.get_Rows();
        TableRow titleRow = rows.get_Item(2);
        
        // Cast the second item in the controls collection of cell one as a 
        // DropDownList.
        DropDownList title = (DropDownList)titleRow.get_Cells().get_Item(1).
            get_Controls().get_Item(1);
        SqlParameter titleParam = new SqlParameter(
            "@Title", title.get_SelectedValue());

        e.get_Command().get_Parameters().Add(titleParam);
    } //On_Inserting

    private void On_Inserted(Object sender, SqlDataSourceStatusEventArgs e)
    {
        // Explicitly call DataBind to refresh the data
        // and show the newly inserted row.
        GridView1.DataBind();
    } //On_Inserted
</SCRIPT>

<HTML>
  <BODY>
    <FORM runat="server">

      <asp:GridView
        id="GridView1"
        runat="server"
        AutoGenerateColumns="False"
        DataKeyNames="EmployeeID"
        SelectedIndex="0"
        DataSourceID="SqlDataSource1">
        <Columns>
          <asp:BoundField HeaderText="First Name" DataField="FirstName" />
          <asp:BoundField HeaderText="Last Name" DataField="LastName" />
          <asp:BoundField HeaderText="Title" DataField="Title" />
          <asp:ButtonField ButtonType="Link" CommandName="Select" Text="Details..." />
        </Columns>
      </asp:GridView>

      <asp:SqlDataSource
        id="SqlDataSource1"
        runat="server"
        ConnectionString="Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;"
        SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees">
      </asp:SqlDataSource>

      <HR>

      <asp:DetailsView
        id="DetailsView1"
        runat="server"
        DataSourceID="SqlDataSource2"
        AutoGenerateRows="False"
        AutoGenerateInsertButton="True">
        <Fields>
          <asp:BoundField HeaderText="First Name" DataField="FirstName" ReadOnly="False"/>
          <asp:BoundField HeaderText="Last Name" DataField="LastName" ReadOnly="False"/>
          <asp:TemplateField HeaderText="Title">
            <ItemTemplate>
              <asp:DropDownList
                runat="server">
                <asp:ListItem Selected>Sales Representative</asp:ListItem>
                <asp:ListItem>Sales Manager</asp:ListItem>
                <asp:ListItem>Vice President, Sales</asp:ListItem>
              </asp:DropDownList>
            </ItemTemplate>
          </asp:TemplateField>
          <asp:BoundField HeaderText="Notes" DataField="Notes" ReadOnly="False"/>
        </Fields>
      </asp:DetailsView>


      <asp:SqlDataSource
        id="SqlDataSource2"
        runat="server"
        ConnectionString="Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;"
        SelectCommand="SELECT * FROM Employees"
        InsertCommand="INSERT INTO Employees(FirstName,LastName,Title,Notes)VALUES (@FirstName,@LastName,@Title,@Notes)"
        OnInserting="On_Inserting"
        OnInserted="On_Inserted"
        FilterExpression="EmployeeID=@EmployeeID">
        <FilterParameters>
          <asp:ControlParameter Name="EmployeeID" ControlId="GridView1" PropertyName="SelectedDataKey.Value"/>
        </FilterParameters>
      </asp:SqlDataSource>

    </FORM>
  </BODY>
</HTML>

The following code example demonstrates how to handle the RowUpdating event raised by the GridView control, to possibly cancel a database action performed by a SqlDataSource control associated with the GridView control.

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JScript

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<%@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">

 ' Set helper text and cancel the update if the values submitted to update the row
 ' do not meet requirements.
 Sub OnRowUpdatingHandler(ByVal source As Object, ByVal e As GridViewUpdateEventArgs)
    If e.OldValues(0).Equals("Nancy") Then
        e.Cancel = "True"
        Label1.Text="This Row is Not Updatable!"
    End If
 End Sub 'OnRowUpdatingHandler

 ' Ensure any helper text is cleared.
 Sub OnRowCancellingHandler(ByVal source As Object, ByVal e As GridViewCancelEditEventArgs)
    Label1.Text=""
 End Sub 'OnRowCancellingHandler
</SCRIPT>


<HTML>
  <BODY>
    <FORM runat="server">

      <asp:SqlDataSource
          id="SqlDataSource1"
          runat="server"
          DataSourceMode="DataSet"
          ConnectionString="<%$ ConnectionStrings:MyNorthwind%>"
          SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees"
          UpdateCommand="Update Employees SET FirstName=@FirstName,LastName=@LastName,Title=@Title WHERE EmployeeID=@EmployeeID">
      </asp:SqlDataSource>

      <asp:GridView
          id="GridView1"
          runat="server"
          AutoGenerateColumns="False"
          DataKeyNames="EmployeeID"
          AutoGenerateEditButton="True"
          DataSourceID="SqlDataSource1"
          OnRowUpdating="OnRowUpdatingHandler"
          OnRowCancellingEdit="OnRowCancellingHandler">
          <columns>
              <asp:BoundField HeaderText="First Name" DataField="FirstName" />
              <asp:BoundField HeaderText="Last Name" DataField="LastName" />
              <asp:BoundField HeaderText="Title" DataField="Title" />
          </columns>
      </asp:GridView>

      <asp:Label
          id="Label1"
          runat="server">
      </asp:Label>

    </FORM>
  </BODY>
</HTML>

Copy

<%@Page  Language="VJ#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<SCRIPT runat="server">

    // Set helper text and cancel the update if the values submitted to update 
    // the row do not meet requirements.
    private void OnRowUpdatingHandler(Object source, GridViewUpdateEventArgs e)
    {
        // You can examine the values submitted by the user and perform 
        // additional processing as required.
        if (e.get_OldValues().get_Item(0).Equals("Nancy")) {
            e.set_Cancel(true);
            Label1.set_Text("This Row is Not Updatable!");
        }
    } //OnRowUpdatingHandler

    // Ensure any helper text is cleared.
    private void OnRowCancellingHandler(Object source, 
        GridViewCancelEditEventArgs e)
    {
        Label1.set_Text("");
    } //OnRowCancellingHandler

</SCRIPT>

<HTML>
  <BODY>
    <FORM runat="server">

      <asp:SqlDataSource
          id="SqlDataSource1"
          runat="server"
          DataSourceMode="DataSet"
          ConnectionString="Data Source=localhost;Integrated Security=SSPI;Initial Catalog=Northwind;"
          SelectCommand="SELECT EmployeeID,FirstName,LastName,Title FROM Employees"
          UpdateCommand="Update Employees SET FirstName=@FirstName,LastName=@LastName,Title=@Title WHERE EmployeeID=@EmployeeID">
      </asp:SqlDataSource>

      <asp:GridView
          id="GridView1"
          runat="server"
          AutoGenerateColumns="False"
          DataKeyNames="EmployeeID"
          AutoGenerateEditButton="True"
          DataSourceID="SqlDataSource1"
          OnRowUpdating="OnRowUpdatingHandler"
          OnRowCancellingEdit="OnRowCancellingHandler">
          <Columns>
              <asp:BoundField HeaderText="First Name" DataField="FirstName" />
              <asp:BoundField HeaderText="Last Name" DataField="LastName" />
              <asp:BoundField HeaderText="Title" DataField="Title" />
          </Columns>
      </asp:GridView>

      <asp:Label
          id="Label1"
          runat="server">
      </asp:Label>

    </FORM>
  </BODY>
</HTML>

Platforms

Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

Version Information

.NET Framework

Supported in: 2.0

Reference

System.Web.UI.WebControls Namespace
SqlDataSourceStatusEventHandler
SqlDataSource Class
OnUpdating
OnInserting
OnDeleting

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