GridViewCancelEditEventHandler Delegate

Definition

Represents the method that handles the RowCancelingEdit event of a GridView control.

C#
public delegate void GridViewCancelEditEventHandler(object sender, GridViewCancelEditEventArgs e);

Parameters

sender
Object

The source of the event.

e
GridViewCancelEditEventArgs

A GridViewCancelEditEventArgs object that contains the event data.

Examples

The following example demonstrates how to programmatically add a GridViewCancelEditEventHandler delegate to the RowCancelingEdit event of a GridView control.

ASP.NET (C#)

<%@ 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 Page_Load(Object sender, EventArgs e)
  {
        
    // Create a new GridView object.
    GridView customerGridView = new GridView();
         
    // Set the GridView object's properties.
    customerGridView.ID = "CustomersGridView";
    customerGridView.DataSourceID = "CustomersSqlDataSource";
    customerGridView.AutoGenerateColumns = true;
    customerGridView.AutoGenerateEditButton = true;
    customerGridView.DataKeyNames = new String[] { "CustomerID" };
        
    // Programmatically register the event-handling methods.
    customerGridView.RowCancelingEdit += new GridViewCancelEditEventHandler(this.CustomersGridView_RowCancelingEdit);
    customerGridView.RowUpdated += new GridViewUpdatedEventHandler(this.CustomersGridView_RowUpdated);
        
    // Add the GridView object to the Controls collection
    // of the PlaceHolder control.
    GridViewPlaceHolder.Controls.Add(customerGridView);
        
  }

  void CustomersGridView_RowCancelingEdit(Object sender, GridViewCancelEditEventArgs e)
  {
    
    // Display a message indicating that the update operation was canceled.
    Message.Text = "Update for row " + e.RowIndex.ToString() + " canceled."; 
    
  }

  void CustomersGridView_RowUpdated(Object sender, GridViewUpdatedEventArgs e)
  {

    // The update operation was successful. Clear the message label.
    Message.Text = "";

  }

</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridViewCancelEditEventHandler Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridViewCancelEditEventHandler Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"
        runat="server"/>
                
      <br/>
            
      <asp:placeholder id="GridViewPlaceHolder"
        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>

The following example demonstrates how to declaratively add a GridViewCancelEditEventHandler delegate to the RowCancelingEdit event of a GridView control.

ASP.NET (C#)

<%@ 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_RowCancelingEdit(Object sender, GridViewCancelEditEventArgs e)
  {
    
    // Retrieve the row that raised the event from the Rows
    // collection of the GridView control.
    GridViewRow row = CustomersGridView.Rows[e.RowIndex];
    
    // The update operation was canceled. Display the 
    // primary key of the row. In this example, the primary
    // key is displayed in the second column of the GridView
    // control. To access the text of the column, use the Cells
    // collection of the row.
    Message.Text = "Update for item " + row.Cells[1].Text + " Canceled."; 
    
  }

  void CustomersGridView_RowEditing(Object sender, GridViewEditEventArgs e)
  {

    // The GridView control is entering edit mode. Clear the message label.
    Message.Text = "";

  }
  
  void CustomersGridView_RowUpdated(Object sender, GridViewUpdatedEventArgs e)
  {

    // The update operation was successful. Clear the message label.
    Message.Text = "";

  }
    
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
  <head runat="server">
    <title>GridView RowCancelingEdit Example</title>
</head>
<body>
    <form id="form1" runat="server">
        
      <h3>GridView RowCancelingEdit Example</h3>
            
      <asp:label id="Message"
        forecolor="Red"
        runat="server"/>
                
      <br/>
      
      <!-- The GridView control automatically sets the columns     -->
      <!-- specified in the datakeynames attribute 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"
        onrowcancelingedit="CustomersGridView_RowCancelingEdit"
        onrowediting="CustomersGridView_RowEditing" 
        onrowupdated="CustomersGridView_RowUpdated"    
        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]"
        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>

Remarks

The RowCancelingEdit event is raised when the Cancel button of a row in edit mode is clicked, but before the row exits edit mode. This allows you to provide an event-handling method that performs a custom routine, such as stopping the cancel operation if it would put the row in an undesired state, whenever this event occurs.

When you create a GridViewCancelEditEventHandler 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 Handling and Raising Events.

Extension Methods

GetMethodInfo(Delegate)

Gets an object that represents the method represented by the specified delegate.

Applies to

Product Versions
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

See also