GridView.RowCancelingEdit Událost
Definice
Důležité
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Nastane při kliknutí na tlačítko Zrušit v řádku v režimu úprav, ale před ukončením režimu úprav.
public:
event System::Web::UI::WebControls::GridViewCancelEditEventHandler ^ RowCancelingEdit;public event System.Web.UI.WebControls.GridViewCancelEditEventHandler RowCancelingEdit;member this.RowCancelingEdit : System.Web.UI.WebControls.GridViewCancelEditEventHandler Public Custom Event RowCancelingEdit As GridViewCancelEditEventHandler Event Type
Příklady
Následující příklad ukazuje, jak použít RowCancelingEdit událost k zobrazení zprávy o zrušení, když uživatel zruší operaci aktualizace ovládacího prvku GridView .
<%@ 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>
<%@ 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">
Sub CustomersGridView_RowCancelingEdit(ByVal sender As Object, ByVal e As GridViewCancelEditEventArgs)
' Retrieve the row that raised the event from the Rows
' collection of the GridView control.
Dim row As GridViewRow = 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."
End Sub
Sub CustomersGridView_RowEditing(ByVal sender As Object, ByVal e As GridViewEditEventArgs)
' The GridView control is entering edit mode. Clear the message label.
Message.Text = ""
End Sub
Sub CustomersGridView_RowUpdated(ByVal sender As Object, ByVal e As GridViewUpdatedEventArgs)
' The update operation was successful. Clear the message label.
Message.Text = ""
End Sub
</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>
Následující příklad ukazuje, jak použít RowCancelingEdit událost ke zrušení operace aktualizace, když je zdroj dat nastaven programově.
<%@ 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>
Poznámky
Událost RowCancelingEdit se vyvolá při kliknutí na tlačítko Zrušit řádku v režimu úprav, ale před ukončením režimu úprav. To vám umožní poskytnout metodu zpracování událostí, která provádí vlastní rutinu, například zastavení operace zrušení, pokud by se řádek dostal do nežádoucího stavu, kdykoli dojde k této události.
GridViewCancelEditEventArgs Objekt je předán metodě zpracování událostí, která umožňuje určit index aktuálního řádku a označit, že operace zrušení by měla být zastavena. Pokud chcete zastavit operaci zrušení, nastavte Cancel vlastnost objektu GridViewCancelEditEventArgs na truehodnotu .
Další informace o zpracování událostí najdete v tématu Zpracování a vyvolávání událostí.
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