Log In
Home
Support
Demos
Documentation
Blogs
Training
Webinars
[Expand]General Information
[Collapse]WinForms Controls
  Prerequisites
 [Expand]What's Installed
 [Expand]Build an Application
 [Collapse]Controls and Libraries
  [Expand]Forms and User Controls
  [Expand]Messages, Notifications and Dialogs
  [Expand]Editors and Simple Controls
  [Expand]Ribbon, Bars and Menu
  [Expand]Application UI Manager
  [Expand]Docking Library
  [Expand]Data Grid
  [Expand]Vertical Grid
  [Collapse]Pivot Grid
   [Expand]Getting Started
   [Expand]Fundamentals
   [Collapse]Binding to Data
     Binding to Data Overview
    [Expand]Data Source Configuration Wizard
    [Expand]OLAP Data Source
    [Expand]Database Server Mode
     Unbound Fields
     Local Data Stores
     Asynchronous Mode
   [Expand]Data Shaping
   [Expand]Data Analysis
   [Expand]Layout
   [Expand]Focus and Navigation
   [Expand]Printing and Exporting
   [Expand]Appearance
   [Expand]Design-time Features
   [Expand]Miscellaneous
   [Expand]UI Elements
   [Expand]End-User Capabilities
   [Expand]Examples
   [Expand]Member Tables
  [Expand]Tree List
  [Expand]Chart Control
  [Expand]Diagrams
  [Expand]Gauges
  [Expand]Map Control
  [Expand]Scheduler
  [Expand]Spreadsheet
  [Expand]Rich Text Editor
  [Expand]Spell Checker
  [Expand]Form Layout Managers
  [Expand]Navigation Controls
  [Expand]Printing-Exporting
  [Expand]PDF Viewer
   Reporting
  [Expand]Snap
  [Expand]TreeMap Control
 [Expand]Common Features
  Get More Help
 [Expand]API Reference
[Expand]ASP.NET Controls and MVC Extensions
[Expand]ASP.NET Bootstrap Controls
[Expand]ASP.NET Core Bootstrap Controls
[Expand]WPF Controls
[Expand]Xamarin Controls
[Expand]Windows 10 App Controls
[Expand]Document Server
[Expand]Reporting
[Expand]Report Server
[Expand]Dashboard
[Expand]eXpressApp Framework
[Expand]CodeRush
[Expand]CodeRush Classic
[Expand]Cross-Platform Core Libraries
[Expand]Tools and Utilities
 End-User Documentation

Asynchronous Mode

The PivotGridControl can perform data-aware operations (retrieving data from the server, sorting, grouping, filtering data and calculating summaries) in a background thread, allowing the entire application to stay responsive while these operations are in progress.

Expanded Overview

If the Pivot Grid Control is working with a large dataset, retrieving data from a data source as well as performing various data-aware operations, such as sorting or filtering data, may take a considerable amount of time. In a standard (synchronous) mode, the entire application would not respond to user actions until the Pivot Grid Control completes the required operations, since the primary UI thread is busy. End-users may notice a small or considerable application freeze.

In asynchronous mode, only the Pivot Grid Control is frozen. The application continues interacting with an end-user, while the control processes data in a background thread. While processing data, the Pivot Grid Control displays a loading panel to indicate that this control is busy, and will not respond to user actions until the operation is completed.

Expanded Asynchronous Operations

End-User Operations

You can specify whether data-aware operations caused by end-user actions run synchronously or asynchronously. To do this, use the PivotGridOptionsBehaviorBase.UseAsyncMode property. If this property is set to true, all operations performed via the UI are asynchronous.

Operations Run In Code

In code, you can perform both synchronous and asynchronous operations, regardless of the UI settings. All methods whose names end with ...Async are asynchronous, i.e., they start executing the related operation in a background thread and return control.

The Pivot Grid Control does not allow the calling of asynchronous methods while an asynchronous operation is in progress. You can check the PivotGridControl.IsAsyncInProgress property to determine whether or not an asynchronous operation is in progress. The PivotGridControl.UserAction property returns which operation is performed.

Note

You can perform a data-aware operation asynchronously even if there is no special ...Async method implemented. The Pivot Grid Control provides the PivotGridControl.EndUpdateAsync method, which allows you to apply the changes made to the control in a background thread. For instance, you can customize the Pivot Grid Control via its properties, wrap the code in the PivotGridControl.BeginUpdate and PivotGridControl.EndUpdateAsync method calls, and the control will be updated asynchronously.

To ensure that the PivotGridControl.EndUpdateAsync method is executed even if an exception occurs, wrap calls to the PivotGridControl.BeginUpdate and PivotGridControl.EndUpdateAsync methods in a try..finally statement.

Note that you cannot start a data-aware operation in code while another operation is running in a background thread.

Subsequent Actions and Operation Result

Each asynchronous method has an overload that allows you to specify custom actions to be performed after the asynchronous operation is completed. To do this, pass an AsyncCompletedHandler delegate that performs the required actions as the asyncCompleted parameter.

If an asynchronous method returns data (an operation result), you must pass a delegate to obtain this data. The delegate's result parameter returns an AsyncOperationResult instance. Use the AsyncOperationResult.Value property to obtain the operation result, and the AsyncOperationResult.Exception property to determine whether or not an exception has been thrown during operation execution.

Execution of Asynchronous Operations

The Pivot Grid Control performs the following actions after an asynchronous operation has been triggered:

  1. closes all popup menus and windows, disables the UI and loses focus (if it was focused);
  2. raises the PivotGridControl.AsyncOperationStarting event;
  3. locks access to pivot grid data through an API, shows a loading panel and runs background calculations.

After background calculations are finished, the Pivot Grid Control does the following:

  1. unlocks access to pivot grid data through an API, hides the loading panel and activates the UI;
  2. raises the PivotGridControl.AsyncOperationCompleted event;
  3. performs internal handling of the operation results;
  4. executes a custom delegate (if one has been passed).

Expanded Event Handling Specifics

In an asynchronous mode, custom painting events are raised before the pivot grid is displayed, and handled in the primary thread while the pivot grid is performing background calculations. This applies to the following events.

For thread safety, you cannot directly access event data while an asynchronous operation is being executed. Otherwise, an exception will be thrown.

When handling custom painting events, use the pivot grid's IThreadSafeAccessible.IsAsyncInProgress property to determine whether the pivot grid is performing background calculations. If this property returns false, you can access event data as you would normally do. Otherwise, you should use a thread-safe event parameter to access it.

Use the event parameter's ThreadSafeArgs property to obtain a thread-safe event parameter. It provides read-only access to basic event parameter members, allowing you to obtain event data when an asynchronous operation is in progress. Event parameter members that cannot be accessed during asynchronous operation do not have corresponding thread-safe event parameter members.

Note

When handling custom painting events, you cannot use PivotGridControl members to access pivot grid data. Use the IThreadSafeAccessible interface members implemented by the PivotGridControl class instead. They allow you to obtain field and group collections, as well as text displayed in field value and data cells.

Expanded Member Tables

This section lists methods exposed by the Pivot Grid Control that perform various operations asynchronously.

Data Binding

Method Description
PivotGridControl.RefreshDataAsync Reloads data from the control data source and recalculates summaries asynchronously.
PivotGridControl.RetrieveFieldsAsync Creates PivotGridField objects for all fields in a data source, and moves them to the specified area, making them visible or hidden. Performs these actions asynchronously.
PivotGridControl.SetDataSourceAsync Sets a data source for Pivot Grid Control and loads data asynchronously.
PivotGridControl.SetOLAPConnectionStringAsync Sets a connection string to a cube in an MS Analysis Services database, and loads data from the cube asynchronously.

Sorting

Method Description
PivotGridControl.ChangeFieldSortOrderAsync Toggles the sort order of the specified field asynchronously.
PivotGridControl.ClearFieldSortingAsync Clears field sorting asynchronously in OLAP mode.
PivotGridControl.SetFieldSortingAsync Sets the specified sort order for the specified field asynchronously.

Layout Operations

Method Description
PivotGridControl.ChangeFieldExpandedAsync Expands or collapses all values of the specified field asynchronously.
PivotGridControl.CollapseAllAsync Collapses all columns and rows in a Pivot Grid Control asynchronously.
PivotGridControl.CollapseAllColumnsAsync Collapses all columns asynchronously.
PivotGridControl.CollapseAllRowsAsync Collapses all rows asynchronously.
PivotGridControl.CollapseValueAsync Collapses the specified column or row asynchronously.
PivotGridControl.ExpandAllAsync Expands all columns and rows in the Pivot Grid Control asynchronously.
PivotGridControl.ExpandAllColumnsAsync Expands all columns asynchronously.
PivotGridControl.ExpandAllRowsAsync Expands all rows asynchronously.
PivotGridControl.ExpandValueAsync Expands the specified column or row asynchronously.

Drill-Down Operations

Method Description
PivotGridControl.CreateDrillDownDataSourceAsync Returns a list of records used to calculate a summary value for the specified cell asynchronously. Allows you to limit the number of records to be returned.
PivotGridControl.CreateOLAPDrillDownDataSourceAsync In OLAP mode, returns a list of records used to calculate a summary value for the specified cell asynchronously. Allows you to specify which columns should be returned.

Control Update

Method Description
PivotGridControl.EndUpdateAsync Unlocks the Pivot Grid Control after the BeginUpdate method call, and starts an asynchronous update.

How would you rate this topic?​​​​​​​