ASPxCardView.CardUpdating Event

Enables you to prevent a card from being updated.

Namespace: DevExpress.Web

Assembly: DevExpress.Web.v24.2.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 to an in-memory DataSource.

function OnClickButtonDel(s, e) {
    card.PerformCallback('Delete');
}

Default.aspx

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

Default.aspx.cs

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;
}
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();
    }
}
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.vb

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
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
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