ASPxPivotGrid.LoadCollapsedStateFromStream(Stream) Method

Restores the collapsed state of field values from the specified stream.

Namespace: DevExpress.Web.ASPxPivotGrid

Assembly: DevExpress.Web.ASPxPivotGrid.v24.2.dll

Declaration

C#

public void LoadCollapsedStateFromStream(
    Stream stream
)

VB.NET

Public Sub LoadCollapsedStateFromStream(
    stream As Stream
)

Parameters

Name	Type	Description
stream	Stream	A Stream descendant from which the collapsed state of field values is read. If null (Nothing in Visual Basic), an exception is raised.

Remarks

Use the LoadCollapsedStateFromStream method to load the collapsed state of field values that has been written to a stream, via the ASPxPivotGrid.SaveCollapsedStateToStream method.

The collapsed states of field values can only be restored in the same layout they were saved in. If the control layout was changed after saving the collapsed states (for instance, some fields have been reordered or hidden), the LoadCollapsedStateFromStream method may have no effect, or may restore the collapsed states incorrectly. To ensure that the collapsed states are loaded correctly, prevent end-users from changing the control layout (use the PivotGridOptionsCustomization.AllowDrag property), or save and load the field values’ collapsed states together with the control layout (use the ASPxPivotGrid.SaveLayoutToStream and ASPxPivotGrid.LoadLayoutFromStream methods).

Note

The LoadCollapsedStateFromStream method has no effect if used when data is not loaded (i.e. the ASPxPivotGrid.DataSource property is not initialized).

Note

The collapsed states for server mode and regular data sources are stored in different formats and not compatible with each other. Some issues can appear on restoring the collapsed state from different data source modes.

Example

Field values' collapsed states can be restored only in the same layout they have been saved in. This example shows how to save and load a control's layout together with collapsed states to ensure that the states are loaded in the appropriate layout.

Default.aspx.cs

using System;
using System.IO;
using System.Web.UI;
using DevExpress.Utils;
using DevExpress.Web.ASPxPivotGrid;

namespace ASPxPivotGrid_SaveLoadCollapsedState {
    public partial class _Default : Page {
        protected void btnSave_Click(object sender, EventArgs e) {
            Session["Layout"] = ASPxPivotGrid1.SaveLayoutToString( PivotGridWebOptionsLayout.DefaultLayout );
            MemoryStream collapseStateStream = (MemoryStream)(Session["CollapseStateStream"]);
            if (collapseStateStream != null) {
                collapseStateStream.Dispose();
            }
            collapseStateStream = new MemoryStream();
            ASPxPivotGrid1.SaveCollapsedStateToStream(collapseStateStream);
            Session["CollapseStateStream"] = collapseStateStream;
        }
        protected void btnLoad_Click(object sender, EventArgs e) {
            MemoryStream collapseStateStream = (MemoryStream)(Session["CollapseStateStream"]);
            string layout = (string)(Session["Layout"]);
            if (layout == null ||
                collapseStateStream == null) {
                return;
            }
            ASPxPivotGrid1.LoadLayoutFromString(layout, PivotGridWebOptionsLayout.DefaultLayout  );
            collapseStateStream.Seek(0, SeekOrigin.Begin);
            ASPxPivotGrid1.LoadCollapsedStateFromStream(collapseStateStream);
        }
        protected void btnClear_Click(object sender, EventArgs e) {
            ASPxPivotGrid1.Fields.Clear();
        }
    }
}

Default.aspx (C#)

<%@ Page Language="C#" AutoEventWireup="true" Codebehind="Default.aspx.cs"
    Inherits="ASPxPivotGrid_SaveLoadCollapsedState._Default" %>
<%@ Register Assembly="DevExpress.Web.v13.1, Version=13.1.8.0,
    Culture=neutral, PublicKeyToken=b88d1754d700e49a"
    Namespace="DevExpress.Web.ASPxEditors"
    TagPrefix="dx" %>
<%@ Register Assembly="DevExpress.Web.ASPxPivotGrid.v13.1, Version=13.1.8.0,
    Culture=neutral, PublicKeyToken=b88d1754d700e49a"
    Namespace="DevExpress.Web.ASPxPivotGrid"
    TagPrefix="dx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <table>
                <tbody>
                    <tr>
                        <td>
                            <dx:ASPxButton ID="btnSave" runat="server" Text="Save"
                            OnClick="btnSave_Click" />
                        </td>
                        <td>
                            <dx:ASPxButton ID="btnLoad" runat="server" Text="Load"
                            OnClick="btnLoad_Click" />
                        </td>
                        <td>
                            <dx:ASPxButton ID="btnClear" runat="server" Text="Clear"
                            OnClick="btnClear_Click" />
                        </td>
                    </tr>
                </tbody>
            </table>
            <dx:ASPxPivotGrid ID="ASPxPivotGrid1" runat="server" DataSourceID="AccessDataSource1"
                Width="677px" OptionsView-ShowHorizontalScrollBar="true">
                <Fields>
                    <dx:PivotGridField ID="fieldProductName" Area="RowArea" AreaIndex="0"
                        Caption="Product Name" FieldName="ProductName">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldYear" Area="ColumnArea" AreaIndex="0" Caption="Year"
                        FieldName="OrderDate" GroupIndex="0" GroupInterval="DateYear"
                        InnerGroupIndex="0" UnboundFieldName="fieldYear">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldExtendedPrice" Area="DataArea" AreaIndex="0"
                        Caption="Extended Price" FieldName="ExtendedPrice">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldQuantity" Area="DataArea" AreaIndex="1"
                        Caption="Quantity" FieldName="Quantity">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldMonth" Area="ColumnArea" AreaIndex="2" Caption="Month"
                        FieldName="OrderDate" GroupIndex="0" InnerGroupIndex="2"
                        GroupInterval="DateMonth" UnboundFieldName="fieldMonth">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldQuarter" Area="ColumnArea" AreaIndex="1"
                        Caption="Quarter" FieldName="OrderDate" GroupIndex="0"
                        GroupInterval="DateQuarter" InnerGroupIndex="1"
                        UnboundFieldName="fieldQuarter">
                    </dx:PivotGridField>
                </Fields>
                <Groups>
                    <dx:PivotGridWebGroup />
                </Groups>
            </dx:ASPxPivotGrid>
            <asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="~/nwind.mdb"
                SelectCommand="SELECT [ProductName], [ExtendedPrice], [Quantity],
                [OrderDate] FROM [Invoices]">
            </asp:AccessDataSource>
        </div>
    </form>
</body>
</html>

Default.aspx (VB.NET)

<%@ Page Language="vb" AutoEventWireup="true" Codebehind="Default.aspx.vb"
    Inherits="ASPxPivotGrid_SaveLoadCollapsedState._Default" %>
<%@ Register Assembly="DevExpress.Web.v13.1, Version=13.1.8.0,
    Culture=neutral, PublicKeyToken=b88d1754d700e49a"
    Namespace="DevExpress.Web.ASPxEditors"
    TagPrefix="dx" %>
<%@ Register Assembly="DevExpress.Web.ASPxPivotGrid.v13.1, Version=13.1.8.0,
    Culture=neutral, PublicKeyToken=b88d1754d700e49a"
    Namespace="DevExpress.Web.ASPxPivotGrid"
    TagPrefix="dx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <table>
                <tbody>
                    <tr>
                        <td>
                            <dx:ASPxButton ID="btnSave" runat="server" Text="Save"
                            OnClick="btnSave_Click" />
                        </td>
                        <td>
                            <dx:ASPxButton ID="btnLoad" runat="server" Text="Load"
                            OnClick="btnLoad_Click" />
                        </td>
                        <td>
                            <dx:ASPxButton ID="btnClear" runat="server" Text="Clear"
                            OnClick="btnClear_Click" />
                        </td>
                    </tr>
                </tbody>
            </table>
            <dx:ASPxPivotGrid ID="ASPxPivotGrid1" runat="server" DataSourceID="AccessDataSource1"
                Width="677px" OptionsView-ShowHorizontalScrollBar="true">
                <Fields>
                    <dx:PivotGridField ID="fieldProductName" Area="RowArea" AreaIndex="0"
                        Caption="Product Name" FieldName="ProductName">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldYear" Area="ColumnArea" AreaIndex="0" Caption="Year"
                        FieldName="OrderDate" GroupIndex="0" GroupInterval="DateYear"
                        InnerGroupIndex="0" UnboundFieldName="fieldYear">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldExtendedPrice" Area="DataArea" AreaIndex="0"
                        Caption="Extended Price" FieldName="ExtendedPrice">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldQuantity" Area="DataArea" AreaIndex="1"
                        Caption="Quantity" FieldName="Quantity">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldMonth" Area="ColumnArea" AreaIndex="2" Caption="Month"
                        FieldName="OrderDate" GroupIndex="0" InnerGroupIndex="2"
                        GroupInterval="DateMonth" UnboundFieldName="fieldMonth">
                    </dx:PivotGridField>
                    <dx:PivotGridField ID="fieldQuarter" Area="ColumnArea" AreaIndex="1"
                        Caption="Quarter" FieldName="OrderDate" GroupIndex="0"
                        GroupInterval="DateQuarter" InnerGroupIndex="1"
                        UnboundFieldName="fieldQuarter">
                    </dx:PivotGridField>
                </Fields>
                <Groups>
                    <dx:PivotGridWebGroup />
                </Groups>
            </dx:ASPxPivotGrid>
            <asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="~/nwind.mdb"
                SelectCommand="SELECT [ProductName], [ExtendedPrice], [Quantity],
                [OrderDate] FROM [Invoices]">
            </asp:AccessDataSource>
        </div>
    </form>
</body>
</html>

Default.aspx.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.IO
Imports System.Web.UI
Imports DevExpress.Utils
Imports DevExpress.Web.ASPxPivotGrid

Namespace ASPxPivotGrid_SaveLoadCollapsedState
    Partial Public Class _Default
        Inherits Page
        Protected Sub btnSave_Click(ByVal sender As Object, ByVal e As EventArgs)
            Session("Layout") = ASPxPivotGrid1.SaveLayoutToString(PivotGridWebOptionsLayout.DefaultLayout)
            Dim collapseStateStream As MemoryStream = CType(Session("CollapseStateStream"), MemoryStream)
            If collapseStateStream IsNot Nothing Then
                collapseStateStream.Dispose()
            End If
            collapseStateStream = New MemoryStream()
            ASPxPivotGrid1.SaveCollapsedStateToStream(collapseStateStream)
            Session("CollapseStateStream") = collapseStateStream
        End Sub
        Protected Sub btnLoad_Click(ByVal sender As Object, ByVal e As EventArgs)
            Dim collapseStateStream As MemoryStream = CType(Session("CollapseStateStream"), MemoryStream)
            Dim layout As String = CStr(Session("Layout"))
            If layout Is Nothing OrElse collapseStateStream Is Nothing Then
                Return
            End If
            ASPxPivotGrid1.LoadLayoutFromString(layout, PivotGridWebOptionsLayout.DefaultLayout)
            collapseStateStream.Seek(0, SeekOrigin.Begin)
            ASPxPivotGrid1.LoadCollapsedStateFromStream(collapseStateStream)
        End Sub
        Protected Sub btnClear_Click(ByVal sender As Object, ByVal e As EventArgs)
            ASPxPivotGrid1.Fields.Clear()
        End Sub
    End Class
End Namespace