ASPxCardView.CardUpdating Event

Enables you to prevent a card from being updated.

Namespace: DevExpress.Web

Assembly: DevExpress.Web.v18.2.dll

Declaration

C#

public event ASPxDataUpdatingEventHandler CardUpdating

VB.NET

Public Event CardUpdating As ASPxDataUpdatingEventHandler

Event Data

The CardUpdating event's data class is ASPxDataUpdatingEventArgs. The following properties provide information specific to this event:

Property	Description
Cancel	Gets or sets a value indicating whether the event should be canceled. Inherited from CancelEventArgs.
Keys	Gets a dictionary of field name/value pairs that represent the primary key of the row to update.
NewValues	Gets a dictionary that contains the values of the non-key field name/value pairs in the row to be updated.
OldValues	Gets a dictionary that contains the original field name/value pairs in the row to be updated.

Remarks

The CardUpdating event occurs when an end-user has changed cell values and tries to pass them to the data source by clicking the Update command. To cancel the update operation, set the event parameter’s Cancel property to true.

If you use edit form templates, you must process the update manually in the CardUpdating event handler.

After a card has been updated, the ASPxCardView.CardUpdated event is raised.

Example

The example illustrates how to delete selected cards of the ASPxCardView bound with an in-memory DataSource.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-delete-aspxcardview-selected-cards-t271569

Default.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Data;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using DevExpress.Web;

public partial class _Default : System.Web.UI.Page
{
    DataTable table = null;
    protected void Page_Init(object sender, EventArgs e)
    {
        if (!IsPostBack && !IsCallback)
        {
            table = new DataTable();
            table.Columns.Add("ID", typeof(int));
            table.Columns.Add("Data", typeof(string));
            table.PrimaryKey = new DataColumn[] { table.Columns["ID"] };
            for (int i = 0; i < 10; i++)
            {
                table.Rows.Add(new object[] { i, "row " + i.ToString() });
            }
            Session["table"] = table;
        }
        else
            table = (DataTable)Session["table"];
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsCallback && !IsPostBack) ASPxCardView1.DataBind();
    }
    protected void ASPxCardView1_CellEditorInitialize(object sender, DevExpress.Web.ASPxCardViewEditorEventArgs e)
    {
        ASPxCardView grid2 = (ASPxCardView)sender;
        if (e.Column.FieldName == "ID")
        {
            ASPxTextBox textBox = (ASPxTextBox)e.Editor;
            textBox.ClientEnabled = false;
            if (grid2.IsNewCardEditing)
            {
                table = (DataTable)Session["table"];
                textBox.Text = GetNewId().ToString();
            }
        }
    }
    protected void ASPxCardView1_CardInserting(object sender, DevExpress.Web.Data.ASPxDataInsertingEventArgs e)
    {
        table = (DataTable)Session["table"];
        ASPxCardView cv = (ASPxCardView)sender;
        DataRow row = table.NewRow();
        row["ID"] = e.NewValues["ID"];
        row["Data"] = e.NewValues["Data"];
        cv.CancelEdit();
        e.Cancel = true;
        table.Rows.Add(row);
    }
    protected void ASPxCardView1_CardUpdating(object sender, DevExpress.Web.Data.ASPxDataUpdatingEventArgs e)
    {
        table = (DataTable)Session["table"];
        DataRow row = table.Rows.Find(e.Keys[0]);
        row["Data"] = e.NewValues["Data"];
        ASPxCardView1.CancelEdit();
        e.Cancel = true;
    }

    protected void ASPxCardView1_DataBinding(object sender, EventArgs e)
    {
        ASPxCardView1.DataSource = table;
    }
    #region #CustomCallbackMethod
    protected void ASPxCardView1_CustomCallback(object sender, DevExpress.Web.ASPxCardViewCustomCallbackEventArgs e)
    {
        if (e.Parameters == "Delete")
        {
            table = (DataTable)Session["table"];
            List<Object> selectItems = ASPxCardView1.GetSelectedFieldValues("ID");
            foreach (object selectItemId in selectItems)
            {
                table.Rows.Remove(table.Rows.Find(selectItemId));
            }
            ASPxCardView1.DataBind();
            ASPxCardView1.Selection.UnselectAll();
        }
    }
    #endregion #CustomCallbackMethod
    private int GetNewId()
    {
        table = (DataTable)Session["table"];
        if (table.Rows.Count == 0) return 0;
        int max = Convert.ToInt32(table.Rows[0]["ID"]);
        for (int i = 1; i < table.Rows.Count; i++)
        {
            if (Convert.ToInt32(table.Rows[i]["ID"]) > max)
                max = Convert.ToInt32(table.Rows[i]["ID"]);
        }
        return max + 1;
    }
}

Default.aspx (C#)

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<%@ Register assembly="DevExpress.Web.v15.1, Version=15.1.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" namespace="DevExpress.Web" tagprefix="dx" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <script type="text/javascript">
        function OnClickButtonDel(s, e) {
            card.PerformCallback('Delete');
        }
    </script>
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

        <dx:ASPxCardView ID="ASPxCardView1" KeyFieldName="ID" AutoGenerateColumns="False" runat="server" OnCellEditorInitialize="ASPxCardView1_CellEditorInitialize" OnCardInserting="ASPxCardView1_CardInserting" OnCardUpdating="ASPxCardView1_CardUpdating" ClientInstanceName="card" OnCustomCallback="ASPxCardView1_CustomCallback" OnDataBinding="ASPxCardView1_DataBinding">
            <Columns>
                <dx:CardViewTextColumn FieldName="ID" VisibleIndex="0">
                </dx:CardViewTextColumn>
                <dx:CardViewTextColumn FieldName="Data" VisibleIndex="1">
                </dx:CardViewTextColumn>
            </Columns>
            <CardLayoutProperties>
                <Items>
                    <dx:CardViewCommandLayoutItem HorizontalAlign="Right" ShowSelectCheckbox="True">
                    </dx:CardViewCommandLayoutItem>
                    <dx:CardViewColumnLayoutItem ColumnName ="ID" >
                    </dx:CardViewColumnLayoutItem>
                    <dx:CardViewColumnLayoutItem ColumnName="Data" >
                    </dx:CardViewColumnLayoutItem>
                    <dx:EditModeCommandLayoutItem HorizontalAlign="Right">
                    </dx:EditModeCommandLayoutItem>
                </Items>
            </CardLayoutProperties>
        </dx:ASPxCardView>
        <dx:ASPxButton ID="ASPxButton1" runat="server" ClientInstanceName="btn1" AutoPostBack="false" Text="Delete">
            <ClientSideEvents Click="OnClickButtonDel"/>
        </dx:ASPxButton>


    </div>
    </form>
</body>
</html>

Default.aspx (VB.NET)

<%@ Page Language="vb" AutoEventWireup="true" CodeFile="Default.aspx.vb" Inherits="_Default" %>

<%@ Register assembly="DevExpress.Web.v15.1, Version=15.1.4.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" namespace="DevExpress.Web" tagprefix="dx" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <script type="text/javascript">
        function OnClickButtonDel(s, e) {
            card.PerformCallback('Delete');
        }
    </script>
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>

        <dx:ASPxCardView ID="ASPxCardView1" KeyFieldName="ID" AutoGenerateColumns="False" runat="server" OnCellEditorInitialize="ASPxCardView1_CellEditorInitialize" OnCardInserting="ASPxCardView1_CardInserting" OnCardUpdating="ASPxCardView1_CardUpdating" ClientInstanceName="card" OnCustomCallback="ASPxCardView1_CustomCallback" OnDataBinding="ASPxCardView1_DataBinding">
            <Columns>
                <dx:CardViewTextColumn FieldName="ID" VisibleIndex="0">
                </dx:CardViewTextColumn>
                <dx:CardViewTextColumn FieldName="Data" VisibleIndex="1">
                </dx:CardViewTextColumn>
            </Columns>
            <CardLayoutProperties>
                <Items>
                    <dx:CardViewCommandLayoutItem HorizontalAlign="Right" ShowSelectCheckbox="True">
                    </dx:CardViewCommandLayoutItem>
                    <dx:CardViewColumnLayoutItem ColumnName ="ID" >
                    </dx:CardViewColumnLayoutItem>
                    <dx:CardViewColumnLayoutItem ColumnName="Data" >
                    </dx:CardViewColumnLayoutItem>
                    <dx:EditModeCommandLayoutItem HorizontalAlign="Right">
                    </dx:EditModeCommandLayoutItem>
                </Items>
            </CardLayoutProperties>
        </dx:ASPxCardView>
        <dx:ASPxButton ID="ASPxButton1" runat="server" ClientInstanceName="btn1" AutoPostBack="false" Text="Delete">
            <ClientSideEvents Click="OnClickButtonDel"/>
        </dx:ASPxButton>


    </div>
    </form>
</body>
</html>

Default.aspx.vb

Imports System
Imports System.Collections.Generic
Imports System.Linq
Imports System.Data
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports DevExpress.Web

Partial Public Class _Default
    Inherits System.Web.UI.Page

    Private table As DataTable = Nothing
    Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
        If (Not IsPostBack) AndAlso (Not IsCallback) Then
            table = New DataTable()
            table.Columns.Add("ID", GetType(Integer))
            table.Columns.Add("Data", GetType(String))
            table.PrimaryKey = New DataColumn() { table.Columns("ID") }
            For i As Integer = 0 To 9
                table.Rows.Add(New Object() { i, "row " & i.ToString() })
            Next i
            Session("table") = table
        Else
            table = DirectCast(Session("table"), DataTable)
        End If
    End Sub
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
        If (Not IsCallback) AndAlso (Not IsPostBack) Then
            ASPxCardView1.DataBind()
        End If
    End Sub
    Protected Sub ASPxCardView1_CellEditorInitialize(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxCardViewEditorEventArgs)
        Dim grid2 As ASPxCardView = DirectCast(sender, ASPxCardView)
        If e.Column.FieldName = "ID" Then
            Dim textBox As ASPxTextBox = CType(e.Editor, ASPxTextBox)
            textBox.ClientEnabled = False
            If grid2.IsNewCardEditing Then
                table = DirectCast(Session("table"), DataTable)
                textBox.Text = GetNewId().ToString()
            End If
        End If
    End Sub
    Protected Sub ASPxCardView1_CardInserting(ByVal sender As Object, ByVal e As DevExpress.Web.Data.ASPxDataInsertingEventArgs)
        table = DirectCast(Session("table"), DataTable)
        Dim cv As ASPxCardView = DirectCast(sender, ASPxCardView)
        Dim row As DataRow = table.NewRow()
        row("ID") = e.NewValues("ID")
        row("Data") = e.NewValues("Data")
        cv.CancelEdit()
        e.Cancel = True
        table.Rows.Add(row)
    End Sub
    Protected Sub ASPxCardView1_CardUpdating(ByVal sender As Object, ByVal e As DevExpress.Web.Data.ASPxDataUpdatingEventArgs)
        table = DirectCast(Session("table"), DataTable)
        Dim row As DataRow = table.Rows.Find(e.Keys(0))
        row("Data") = e.NewValues("Data")
        ASPxCardView1.CancelEdit()
        e.Cancel = True
    End Sub

    Protected Sub ASPxCardView1_DataBinding(ByVal sender As Object, ByVal e As EventArgs)
        ASPxCardView1.DataSource = table
    End Sub
    #Region "#CustomCallbackMethod"
    Protected Sub ASPxCardView1_CustomCallback(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxCardViewCustomCallbackEventArgs)
        If e.Parameters = "Delete" Then
            table = DirectCast(Session("table"), DataTable)
            Dim selectItems As List(Of Object) = ASPxCardView1.GetSelectedFieldValues("ID")
            For Each selectItemId As Object In selectItems
                table.Rows.Remove(table.Rows.Find(selectItemId))
            Next selectItemId
            ASPxCardView1.DataBind()
            ASPxCardView1.Selection.UnselectAll()
        End If
    End Sub
    #End Region ' #CustomCallbackMethod
    Private Function GetNewId() As Integer
        table = DirectCast(Session("table"), DataTable)
        If table.Rows.Count = 0 Then
            Return 0
        End If
        Dim max As Integer = Convert.ToInt32(table.Rows(0)("ID"))
        For i As Integer = 1 To table.Rows.Count - 1
            If Convert.ToInt32(table.Rows(i)("ID")) > max Then
                max = Convert.ToInt32(table.Rows(i)("ID"))
            End If
        Next i
        Return max + 1
    End Function
End Class