PivotGridControl.CreateDrillDownDataSourceAsync(AsyncCompletedHandler) Method

Returns a list of records used to calculate summary values for all cells asynchronously.

Namespace: DevExpress.XtraPivotGrid

Assembly: DevExpress.XtraPivotGrid.v20.1.dll

Declaration

public void CreateDrillDownDataSourceAsync(
    AsyncCompletedHandler asyncCompleted
)
Public Sub CreateDrillDownDataSourceAsync(
    asyncCompleted As AsyncCompletedHandler
)

Parameters

Name Type Description
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 obtain underlying data for a particular cell, use other overloads of the CreateDrillDownDataSourceAsync method that take the columnIndex and rowIndex parameters.

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

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.

Examples

This example performs an asynchronous operation that creates a drill-down data source for the selected PivotGrid cell and gets the operation result - the underlying data source.

In this example, the PivotGrid control is bound to the LinqServerModeSource data source and operates in server mode.

The PivotGridControl.CellClick event handler calls the PivotGridControl.CreateDrillDownDataSourceAsync method to generate a drill-down data source for the selected cell. The method parameter specifies the number of records to return. The method also specifies the columns to add to the the data set.

The last item in the method's parameter list is the AsyncCompletedHandler delegate. The delegate is executed when the operation is complete. The delegate's result parameter is the AsyncOperationResult instance whose Value property contains the result of the operation.

The operation's result is cast to the PivotDrillDownDataSource and the GridControl displays the underlying records in the auxiliary DrillDown form.

NOTE

The complete sample project How to Create the Underlying Data Source (Drill-Down) in an Asynchronous Operation is available in the DevExpress Examples repository.

using DevExpress.XtraPivotGrid;
using System;
using System.Collections.Generic;

namespace XtraPivotGrid_CreateDrillDownDataSourceAsync {
    public partial class Form1 : DevExpress.XtraEditors.XtraForm
    {
        DrillDownForm dForm;
        public Form1()
        {
            InitializeComponent();
            this.Load += Form1_Load;
            pivotGridControl1.CellClick += pivotGridControl1_CellClick;
            // This line of code is generated by Data Source Configuration Wizard
            linqServerModeSource1.QueryableSource = new XtraPivotGrid_CreateDrillDownDataSourceAsync.DataClasses1DataContext().Invoices;
        }
        private void pivotGridControl1_CellClick(object sender, 
            DevExpress.XtraPivotGrid.PivotCellEventArgs e) {
            PivotGridControl pivot = sender as PivotGridControl;
            if (dForm.IsDisposed) LoadDrillDownForm();

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

                // Get the record set associated with the clicked cell.
                pivot.CreateDrillDownDataSourceAsync(e.ColumnIndex, e.RowIndex, 25, new List<string> { "ProductName","Quantity" }, result => {
                    // The 'result' parameter of the delegate returns an AsyncOperationResult instance.
                    // The AsyncOperationResult.Value property contains a record set.
                    dForm.DataSource = (PivotDrillDownDataSource)result.Value;
                });
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            LoadDrillDownForm();
        }
        private void LoadDrillDownForm()
        {
            dForm = new DrillDownForm();
            dForm.Show();
        }
    }
}
See Also