GridView.RowUpdating Event
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Occurs when a row's Update button is clicked, but before the GridView control updates the row.
public:
event System::Web::UI::WebControls::GridViewUpdateEventHandler ^ RowUpdating;public event System.Web.UI.WebControls.GridViewUpdateEventHandler RowUpdating;member this.RowUpdating : System.Web.UI.WebControls.GridViewUpdateEventHandler Public Custom Event RowUpdating As GridViewUpdateEventHandler Event Type
Examples
The following example demonstrates how to use the RowUpdating event to update the values in the data source object when the data source is set programmatically.
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
// Create a new table.
DataTable taskTable = new DataTable("TaskList");
// Create the columns.
taskTable.Columns.Add("Id", typeof(int));
taskTable.Columns.Add("Description", typeof(string));
taskTable.Columns.Add("IsComplete", typeof(bool) );
//Add data to the new table.
for (int i = 0; i < 20; i++)
{
DataRow tableRow = taskTable.NewRow();
tableRow["Id"] = i;
tableRow["Description"] = "Task " + i.ToString();
tableRow["IsComplete"] = false;
taskTable.Rows.Add(tableRow);
}
//Persist the table in the Session object.
Session["TaskTable"] = taskTable;
//Bind data to the GridView control.
BindData();
}
}
protected void TaskGridView_PageIndexChanging(object sender, GridViewPageEventArgs e)
{
TaskGridView.PageIndex = e.NewPageIndex;
//Bind data to the GridView control.
BindData();
}
protected void TaskGridView_RowEditing(object sender, GridViewEditEventArgs e)
{
//Set the edit index.
TaskGridView.EditIndex = e.NewEditIndex;
//Bind data to the GridView control.
BindData();
}
protected void TaskGridView_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
//Reset the edit index.
TaskGridView.EditIndex = -1;
//Bind data to the GridView control.
BindData();
}
protected void TaskGridView_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
//Retrieve the table from the session object.
DataTable dt = (DataTable)Session["TaskTable"];
//Update the values.
GridViewRow row = TaskGridView.Rows[e.RowIndex];
dt.Rows[row.DataItemIndex]["Id"] = ((TextBox)(row.Cells[1].Controls[0])).Text;
dt.Rows[row.DataItemIndex]["Description"] = ((TextBox)(row.Cells[2].Controls[0])).Text;
dt.Rows[row.DataItemIndex]["IsComplete"] = ((CheckBox)(row.Cells[3].Controls[0])).Checked;
//Reset the edit index.
TaskGridView.EditIndex = -1;
//Bind data to the GridView control.
BindData();
}
private void BindData()
{
TaskGridView.DataSource = Session["TaskTable"];
TaskGridView.DataBind();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>GridView example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="TaskGridView" runat="server"
AutoGenerateEditButton="True"
AllowPaging="true"
OnRowEditing="TaskGridView_RowEditing"
OnRowCancelingEdit="TaskGridView_RowCancelingEdit"
OnRowUpdating="TaskGridView_RowUpdating"
OnPageIndexChanging="TaskGridView_PageIndexChanging">
</asp:GridView>
</div>
</form>
</body>
</html>
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Data" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Protected Sub Page_Load()
If Not Page.IsPostBack Then
' Create a new table.
Dim taskTable As New DataTable("TaskList")
' Create the columns.
taskTable.Columns.Add("Id", GetType(Integer))
taskTable.Columns.Add("Description", GetType(String))
taskTable.Columns.Add("IsComplete", GetType(Boolean))
'Add data to the new table.
For i = 0 To 19
Dim tableRow = taskTable.NewRow()
tableRow("Id") = i
tableRow("Description") = "Task " + i.ToString()
tableRow("IsComplete") = False
taskTable.Rows.Add(tableRow)
Next
'Persist the table in the Session object.
Session("TaskTable") = taskTable
'Bind data to the GridView control.
BindData()
End If
End Sub
Protected Sub TaskGridView_PageIndexChanging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
TaskGridView.PageIndex = e.NewPageIndex
'Bind data to the GridView control.
BindData()
End Sub
Protected Sub TaskGridView_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
'Set the edit index.
TaskGridView.EditIndex = e.NewEditIndex
'Bind data to the GridView control.
BindData()
End Sub
Protected Sub TaskGridView_RowCancelingEdit()
'Reset the edit index.
TaskGridView.EditIndex = -1
'Bind data to the GridView control.
BindData()
End Sub
Protected Sub TaskGridView_RowUpdating(ByVal sender As Object, ByVal e As GridViewUpdateEventArgs)
'Retrieve the table from the session object.
Dim dt = CType(Session("TaskTable"), DataTable)
'Update the values.
Dim row = TaskGridView.Rows(e.RowIndex)
dt.Rows(row.DataItemIndex)("Id") = (CType((row.Cells(1).Controls(0)), TextBox)).Text
dt.Rows(row.DataItemIndex)("Description") = (CType((row.Cells(2).Controls(0)), TextBox)).Text
dt.Rows(row.DataItemIndex)("IsComplete") = (CType((row.Cells(3).Controls(0)), CheckBox)).Checked
'Reset the edit index.
TaskGridView.EditIndex = -1
'Bind data to the GridView control.
BindData()
End Sub
Private Sub BindData()
TaskGridView.DataSource = Session("TaskTable")
TaskGridView.DataBind()
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>GridView example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:GridView ID="TaskGridView" runat="server"
AutoGenerateEditButton="True"
AllowPaging="true"
OnRowEditing="TaskGridView_RowEditing"
OnRowCancelingEdit="TaskGridView_RowCancelingEdit"
OnRowUpdating="TaskGridView_RowUpdating"
OnPageIndexChanging="TaskGridView_PageIndexChanging">
</asp:GridView>
</div>
</form>
</body>
</html>
Remarks
The RowUpdating event is raised when a row's Update button is clicked, but before the GridView control updates the row. This enables you to provide an event-handling method that performs a custom routine, such as canceling the update operation, whenever this event occurs.
A GridViewUpdateEventArgs object is passed to the event-handling method, which enables you to determine the index of the current row and to indicate that the update operation should be canceled. To cancel the update operation, set the Cancel property of the GridViewUpdateEventArgs object to true. You can also manipulate the Keys, OldValues, and NewValues collections, if necessary, before the values are passed to the data source. A common way to use these collections is to HTML-encode the values supplied by the user before they are stored in the data source. This helps to prevent script injection attacks.
Note
The Keys, OldValues and NewValues collections are automatically populated only when the GridView control is bound to data by using the DataSourceID property.
For more information about how to handle events, see Handling and Raising Events.
