PivotGridControl.CreateDrillDownDataSourceAsync(Int32, Int32, AsyncCompletedHandler) Method

Returns a list of records used to calculate a summary value for the specified cell asynchronously.

Namespace: DevExpress.XtraPivotGrid

Assembly: DevExpress.XtraPivotGrid.v18.2.dll

Declaration

C#

public void CreateDrillDownDataSourceAsync(
    int columnIndex,
    int rowIndex,
    AsyncCompletedHandler asyncCompleted
)

VB.NET

Public Sub CreateDrillDownDataSourceAsync(
    columnIndex As Integer,
    rowIndex As Integer,
    asyncCompleted As AsyncCompletedHandler
)

Parameters

Name	Type	Description
columnIndex	Int32	A zero-based integer which identifies the visible index of the column. Pass -1 as a column index to obtain the column’s Grand Total.
rowIndex	Int32	A zero-based integer which identifies the visible index of the row. Pass -1 as a row index to obtain the row’s Grand Total.
asyncCompleted	AsyncCompletedHandler	A AsyncCompletedHandler delegate referencing a method that should be executed after the operation is completed. The drill-down data source is passed to this method as a parameter.

Remarks

The CreateDrillDownDataSourceAsync method is asynchronous. It starts executing the related operation in a background thread, and immediately returns control. The primary UI thread is not blocked, allowing the application to continue responding to end-user actions. For more information about the asynchronous mode, see Asynchronous Mode.

The drill-down data source (a PivotDrillDownDataSource instance) is passed to the asyncCompleted delegate via the result parameter. This parameter returns an AsyncOperationResult instance. Use the AsyncOperationResult.Value property to obtain the drill-down data source.

To create a drill-down data source synchronously, use the PivotGridControl.CreateDrillDownDataSource method.

Note

In OLAP mode, calling this method is equivalent to calling the PivotGridControl.CreateOLAPDrillDownDataSourceAsync method with the customColumns parameter set to null.

Note

Calling the CreateDrillDownDataSourceAsync method from the PivotGridControl.CustomSummary and PivotGridControl.CustomUnboundFieldData event handlers may result in the stack overflow exception. To provide custom cell values that require obtaining the underlying data to be calculated, handle the PivotGridControl.CustomCellValue event, and call the CreateDrillDownDataSourceAsync method in the event handler.

Example

This example shows how to use asynchronous operations that return the result.

In this example, the PivotGridControl.CellClick event is handled to generate a drill-down data source for a specific cell using the PivotGridControl.CreateDrillDownDataSourceAsync method. The AsyncCompletedHandler delegate is passed as a method parameter. The referenced method is executed after the operation is completed, allowing to obtain the result via the result parameter of the delegate. This parameter returns an AsyncOperationResult instance.

The AsyncOperationResult.Value property is used to obtain a record set associated with the clicked cell. Then, the PivotDrillDownDataSource.RowCount property is used to determine the number of records in the data source for this cell.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-use-asynchronous-operations-that-return-the-result-e4567

Form1.cs

using System;
using System.Windows.Forms;
using DevExpress.XtraPivotGrid;

namespace XtraPivotGrid_CreateDrillDownDataSourceAsync {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e) {

            // Binds the pivot grid to data.
            this.salesPersonTableAdapter.Fill(this.nwindDataSet.SalesPerson);
        }

        private void pivotGridControl1_CellClick(object sender, 
            DevExpress.XtraPivotGrid.PivotCellEventArgs e) {
            PivotGridControl pivot = sender as PivotGridControl;

            //Checks whether an asynchronous operation is in progress.
            if (!pivot.IsAsyncInProgress)

                // Gets the record set associated with the clicked cell.
                // The delegate is passed to obtain this record set.
                pivot.CreateDrillDownDataSourceAsync(e.ColumnIndex, e.RowIndex, result => {

                    // The 'result' parameter of the delegate returns an AsyncOperationResult instance.
                    // The AsyncOperationResult.Value property is used to obtain the record set, 
                    // the PivotDrillDownDataSource.RowCount property is used to obtain the number 
                    // of records in the data source.
                    label1.Text = "RowCount = " + ((PivotDrillDownDataSource)result.Value).RowCount;
                });
        }
    }
}

Form1.vb

Imports System
Imports System.Windows.Forms
Imports DevExpress.XtraPivotGrid

Namespace XtraPivotGrid_CreateDrillDownDataSourceAsync
    Partial Public Class Form1
        Inherits Form

        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load

            ' Binds the pivot grid to data.
            Me.salesPersonTableAdapter.Fill(Me.nwindDataSet.SalesPerson)
        End Sub

        Private Sub pivotGridControl1_CellClick(ByVal sender As Object, ByVal e As DevExpress.XtraPivotGrid.PivotCellEventArgs) Handles pivotGridControl1.CellClick
            Dim pivot As PivotGridControl = TryCast(sender, PivotGridControl)

            'Checks whether an asynchronous operation is in progress.
            If Not pivot.IsAsyncInProgress Then

                ' Gets the record set associated with the clicked cell.
                ' The delegate is passed to obtain this record set.
                pivot.CreateDrillDownDataSourceAsync(e.ColumnIndex, e.RowIndex, Sub(result) label1.Text = "RowCount = " & CType(result.Value, PivotDrillDownDataSource).RowCount)
            End If
                    ' The 'result' parameter of the delegate returns an AsyncOperationResult instance.
                    ' The AsyncOperationResult.Value property is used to obtain the record set, 
                    ' the PivotDrillDownDataSource.RowCount property is used to obtain the number 
                    ' of records in the data source.
        End Sub
    End Class
End Namespace

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the CreateDrillDownDataSourceAsync(Int32, Int32, AsyncCompletedHandler) method.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

winforms-pivot-grid-create-the-underlying-data-source-asynchronously/CS/XtraPivotGrid_CreateDrillDownDataSourceAsync/Form1.cs#L26

// The delegate is passed to obtain this record set.
pivot.CreateDrillDownDataSourceAsync(e.ColumnIndex, e.RowIndex, result => {

VB.NET

winforms-pivot-grid-create-the-underlying-data-source-asynchronously/VB/XtraPivotGrid_CreateDrillDownDataSourceAsync/Form1.vb#L28

    ' of records in the data source.
    If Not pivot.IsAsyncInProgress Then pivot.CreateDrillDownDataSourceAsync(e.ColumnIndex, e.RowIndex, Sub(result) label1.Text = "RowCount = " & CType(result.Value, PivotDrillDownDataSource).RowCount)
End Sub