PivotGridControl.LoadCollapsedStateFromFile(String) Method

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

Namespace: DevExpress.XtraPivotGrid

Assembly: DevExpress.XtraPivotGrid.v19.1.dll

Declaration

C#

public void LoadCollapsedStateFromFile(
    string path
)

VB.NET

Public Sub LoadCollapsedStateFromFile(
    path As String
)

Parameters

Name	Type	Description
path	String	A String value that specifies the path to the file from which the collapsed state of field values is read. If the specified file does not exist, an exception is raised.

Remarks

Use the LoadCollapsedStateFromFile method to load the collapsed state of field values that has been written to a file via the PivotGridControl.SaveCollapsedStateToFile 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 LoadCollapsedStateFromFile 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 and PivotGridOptionsCustomization.AllowHideFields properties), or save and load the field values’ collapsed states together with the control layout (use the PivotGridControl.SaveLayoutToXml and PivotGridControl.RestoreLayoutFromXml methods).

Note

The LoadCollapsedStateFromFile method has no effect if used when data is not loaded (i.e. the PivotGridControl.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.This example displays a pivot grid control and three buttons: Save, Load and Clear. When the Save button is clicked, the control layout and field values' collapsed states are saved to streams via the SaveLayoutToStream and SaveCollapsedStateToStream methods, respectively. On the Load button click, the RestoreLayoutFromStream method is firstly called to restore the layout, and then the collapsed states are loaded using the LoadCollapsedStateFromStream method. This ensures that even if you remove all fields from the pivot grid via the Clear button, the control's state will be restored when you click the Load button.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-save-load-field-values-collapsed-states-together-with-pivot-grids-layout-e20014

Form1.cs

using System;
using System.IO;
using System.Windows.Forms;
using DevExpress.Utils;

namespace XtraPivotGrid_SaveLoadCollapsedState {
    public partial class Form1 : Form {
        MemoryStream layoutStream = new MemoryStream();
        MemoryStream collapseStateStream = new MemoryStream();
        public Form1() {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e) {
            nwindDataSetTableAdapters.ProductReportsTableAdapter adapter =
                new nwindDataSetTableAdapters.ProductReportsTableAdapter();
            pivotGridControl1.DataSource = adapter.GetData();
        }
        private void btnSave_Click(object sender, EventArgs e) {
            layoutStream.Dispose();
            layoutStream = new MemoryStream();
            pivotGridControl1.SaveLayoutToStream(layoutStream, OptionsLayoutBase.FullLayout);
            collapseStateStream.Dispose();
            collapseStateStream = new MemoryStream();
            pivotGridControl1.SaveCollapsedStateToStream(collapseStateStream);
        }
        private void btnLoad_Click(object sender, EventArgs e) {
            layoutStream.Seek(0, SeekOrigin.Begin);
            pivotGridControl1.RestoreLayoutFromStream(layoutStream, OptionsLayoutBase.FullLayout);
            collapseStateStream.Seek(0, SeekOrigin.Begin);
            pivotGridControl1.LoadCollapsedStateFromStream(collapseStateStream);
        }
        private void btnClear_Click(object sender, EventArgs e) {
            pivotGridControl1.Fields.Clear();
        }
    }
}

Form1.vb

Imports Microsoft.VisualBasic
Imports System
Imports System.IO
Imports System.Windows.Forms
Imports DevExpress.Utils

Namespace XtraPivotGrid_SaveLoadCollapsedState
    Partial Public Class Form1
        Inherits Form
        Private layoutStream As New MemoryStream()
        Private collapseStateStream As New MemoryStream()
        Public Sub New()
            InitializeComponent()
        End Sub
        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
            Dim adapter As New nwindDataSetTableAdapters.ProductReportsTableAdapter()
            pivotGridControl1.DataSource = adapter.GetData()
        End Sub
        Private Sub btnSave_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSave.Click
            layoutStream.Dispose()
            layoutStream = New MemoryStream()
            pivotGridControl1.SaveLayoutToStream(layoutStream, OptionsLayoutBase.FullLayout)
            collapseStateStream.Dispose()
            collapseStateStream = New MemoryStream()
            pivotGridControl1.SaveCollapsedStateToStream(collapseStateStream)
        End Sub
        Private Sub btnLoad_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnLoad.Click
            layoutStream.Seek(0, SeekOrigin.Begin)
            pivotGridControl1.RestoreLayoutFromStream(layoutStream, OptionsLayoutBase.FullLayout)
            collapseStateStream.Seek(0, SeekOrigin.Begin)
            pivotGridControl1.LoadCollapsedStateFromStream(collapseStateStream)
        End Sub
        Private Sub btnClear_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnClear.Click
            pivotGridControl1.Fields.Clear()
        End Sub
    End Class
End Namespace